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1
BONGETTA, DANIELE. "Fluorescein-aided neurosurgery." Doctoral thesis, Università degli studi di Pavia, 2018. http://hdl.handle.net/11571/1227773.
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Neurosurgery made enormous advances over the last century. Moving from a meticulous anatomical knowledge of the cerebral structures and passing through the “microscope revolution” we arrived in the modern neuronavigation era in which we can render and correlate real-time the preoperative imaging to the patient. Real life, though, is way different from simulation and technological promises. In fact, some tumours are still almost undistinguishable from the brain in normal vision and our individual estimate of vessel patency may be proved way wrong at the ischemic post operative imaging. Sometimes, even with all the best resources, we are blindly performing life-saving procedures. The development of fluorescent intra-operative tracers tried to address these issues. This PhD thesis is, basically, the synthesis of three years of personal clinical experience on the experimental use of intra-operative Fluorescein in Neurosurgery.
Briefly, I will describe the optical and pharmaceutical properties of Fluorescein and explain how I assembled a low-cost fluorescence detection system. Then I will go through all the fields of Neurosurgery in which I applied this technology.
Firstly, I will report the preliminary results of an ongoing Clinical Trial on the use of Fluorescein as an intra-operative contrast enhancer of the borders of high grade glioma tumours.
Then, the potential advantages of fluorescein use in vascular neurosurgery will be discussed. In particular the use of fluorescein for the evaluation of the exclusion of intra-cerebral aneurysms will be illustrated by means of an explicative case. Similarly, I will report the usefulness of intra-operative fluorescence detection in a case of intra-cerebral cavernoma. Lastly, I will describe the experience of fluorescein staining in the field of Hereditary hemorrhagic telangiectasia and explain the potential advantages of this technique in arteriovenous malformations.
Eventually, I will describe the usefulness of dedicated endoscopic filters for fluorescein detection in trans-nasal skull base procedures. The rationale and preliminary results of the use of fluorescein as an intra-operative contrast medium in pituitary adenoma surgery will be presented. CSF leak detection and pedicled flaps' perfusion evaluation techniques will be also described in detail.Neurosurgery made enormous advances over the last century. Moving from a meticulous anatomical knowledge of the cerebral structures and passing through the “microscope revolution” we arrived in the modern neuronavigation era in which we can render and correlate real-time the preoperative imaging to the patient. Real life, though, is way different from simulation and technological promises. In fact, some tumours are still almost undistinguishable from the brain in normal vision and our individual estimate of vessel patency may be proved way wrong at the ischemic post operative imaging. Sometimes, even with all the best resources, we are blindly performing life-saving procedures. The development of fluorescent intra-operative tracers tried to address these issues. This PhD thesis is, basically, the synthesis of three years of personal clinical experience on the experimental use of intra-operative Fluorescein in Neurosurgery. Briefly, I will describe the optical and pharmaceutical properties of Fluorescein and explain how I assembled a low-cost fluorescence detection system. Then I will go through all the fields of Neurosurgery in which I applied this technology. Firstly, I will report the preliminary results of an ongoing Clinical Trial on the use of Fluorescein as an intra-operative contrast enhancer of the borders of high grade glioma tumours. Then, the potential advantages of fluorescein use in vascular neurosurgery will be discussed. In particular the use of fluorescein for the evaluation of the exclusion of intra-cerebral aneurysms will be illustrated by means of an explicative case. Similarly, I will report the usefulness of intra-operative fluorescence detection in a case of intra-cerebral cavernoma. Lastly, I will describe the experience of fluorescein staining in the field of Hereditary hemorrhagic telangiectasia and explain the potential advantages of this technique in arteriovenous malformations. Eventually, I will describe the usefulness of dedicated endoscopic filters for fluorescein detection in trans-nasal skull base procedures. The rationale and preliminary results of the use of fluorescein as an intra-operative contrast medium in pituitary adenoma surgery will be presented. CSF leak detection and pedicled flaps' perfusion evaluation techniques will be also described in detail.
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Bergqvist, Saga. "Raman spectroscopy in neurosurgery." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-78665.
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Brain tumors or brain cancer is a disease than affects people of all ages. The median age of a person living with a brain tumor is 60 years, it is however a disease that affects children and young adults in high grade. Brain cancer is the second most common type of cancer among children and is also the most common cause of cancer related death among this group. To ensure that the damages on the brain is as small as possible, it is important that a tumor can be diagnosed and removed as early as possible. Previous methods of diagnosis is based on biopsy where a part of the tumor is removed and examinated by a pathologist. This is a time consuming process that also is biased by the human factor, there is therefore a need for a method that can be used \textit{in situ} with an unbiased result. One method that have shown great promise is photensitation with 5-Aminolevoluic acid (5-ALA). However, this method have shown to only work properly on tumors of high malignancy in adults. As a comlpiment to photosentisation, Raman spectroscopy have shown good promise in previous studies. This study was conducted to investigate the use of Raman spectroscopy as a tool for \textit{in situ} brain tumor diagnostics. The use of Raman spectroscopy was tested by comparing two previously performed studies, where they looked at a number of Raman bands from biological markers that are known to change in cancerous tissue as well as the intensity ratio between some Raman bands. A measurement system for Raman spectroscopy was designed and built at Luleå University of Technology where the system were evaluated on tissue samples from conventional meat i.e. pork and beef to ensure that is was possible to achieve spectroscopic information of protein and lipid content in tissue. The measurement system was then transported to Linköpings University where the measurements on six brain tissue samples where performed. The samples came from five different tumors of which one tumor was thought to come from a high malignant tumor based on preliminary histopathological analysis and four from low malignant or benign tumors. Two samples where obtained from the high malignant tumor that was photosentisized with 5-Aminolevoluic acid and one of the samples where illuminated with blue light prior to the Raman spectroscopic measurements. The spectroscopic data was pre-processed before analysis using conventional methods. The analysed spectra from the brain tissue samples showed presence of the Raman bands associated with brain tissue. It was also possible to see Raman bands associated with 5-ALA in the samples that had been photosentisized, however when the tissue had been illuminated with blue light it was also possible to see distinct Raman bands associated with brain tissue. One tissue sample also showed presence of reduced Neuroglobin (NGB). The composition of NGB is also known to change in tumorous tissue and could therefore be used in future work as a biological marker for brain tumors. When comparing the results obtained in this study with the two previously performed, one of the studies showed that two samples were from a tumor of high malignancy and the other from low malignant or benign tumors. This result was in accordance with the preliminary histopathological assessment of the brain tissue samples. When comparing the results to the other study, the results where contradictory and indicated that all tissue samples where from low malignant or benign tumors. The conclusion of this work is that Raman spectroscopy is possible to use as a tool for brain tumor diagnostics. It would be desirable to use this method in combination with 5-ALA staining since the Raman bands from brain tissue could be resolved when the tissue had been illuminated with blue light.Hjärntumörer kan drabba människor i alla åldrar, medelåldern för människor som lever med en hjärntumör är 60 år, men det är ett tillstånd som även drabbar barn och unga i stor utsträckning. Hjärntumörer är den näst vanligaste cancerformen hos barn och är även den främsta orsaken till cancerrelaterad död i den åldergruppen. För att minimera skadorna på hjärnan är det viktigt att en tumör kan lokaliseras och tas bort så tidigt som möjligt. De metoder som används idag bygger framför allt på biopsi, där en del av tumören tas bort och undersöks av en histopatalog. Det är en process som tar lång tid och även påverkas av den mänskliga faktorn, det finns därmed ett behov av en metod som kan avändas \textit{in situ} som ger ett resultat som inte påverkas av den mänskliga faktorn. En metod som har visat lovande resultat är fotosensibilisering med 5-Aminolevulinsyra (5-ALA). Desvärre har den metoden bara visat sig fungera bra för högmaligna tumörer hos vuxna. Som ett komplement till fotosensibilisering har Ramanspektroskopi visat lovande resultat i tidigare genomförda studier. Det här arbetet genomfördes för att undersöka användningen av Ramanspektroskopi som ett verktyg för diagnostisering av hjärntumörer. Som grund användes två tidigare genomförda studier där de undersökte Ramanband från biologiska markörer i hjärnvävnad som ändras i cancerogen vävnad. De undersökte även hur den biokemiska sammansättningen av hjärnvävnaden ändrades genom att jämföra intensiteten av olika Ramanband. Ett mätsystem för Ramanspektroskopi designades och byggdes upp på Luleå Tekniska Universitet där det även testades på vävnad från kött (fläsk och biff). Därefter transporterades mätsystemet till Linköpings Universitet för att genomföra mätningar på sex olika vävnadsprov från fem hjärntumörer av olika malignitet. Baserat på en preliminär histopatalogisk bedömning var en av tumörerna högmalignt och de fyra andra tumörerna var antingen lågmalignta eller benigna. Två av proverna som undersöktes kom från den högmalignta tumören som även var fotosensibilierad med 5-Aminolevulinsyra, varav ett av proverna var belyst med blått ljus innan de Ramanspektroskopiska mätningarna genomfördes. Innan resultatet från Ramanspektroskopiska mätningarna analyserades behandlades datan med konventionella metoder i MatLab. I de resulterade spektrumen gick det att se tydliga Ramanband associerade med hjärnvävnad. Det gick även att se Ramanband associerade med 5-ALA i de två prover som var fotosensibiliserade och i det provet som var belyst med blått ljus innan de spektroskopiska mätningarna gjordes gick det även att se tydliga Ramanband associerade med hjärnvävnad. När resultatet analyserades gick det även att se spektra associerat med reducerat Neuroglobin (NGB) i ett av proverna. Sammansättningen av NGB är också någonting som ändras i cancerogen vävnad och skulle därför också kunna användas som en bilogisk markör för hjärntumörer i framtida studier. När resultaten från den här studien jämfördes med de tidigare studierna indikerade den ena studien att två av vävnadsproverna kom från en högmalignt tumör och att de resterande fyra från lågmaligna eller benigna tumörer, vilket stämmer överens med den preliminära diagnosticeringen av tumörerna. När resultatet istället jämfördes med den andra studien stämde inte resultatet lika bra med den preliminära diagnosticeringen av tumörerna. Metoden presenterad av Zhou m.fl. indikerade att alla tumörer kom från lågmaligna eller benigna tumörer. Slutsaten av det här arbetet är att Ramanspektroskopi skulle kunna användas som en metod för diagnosticering av hjärntumörer. Metoden skulle även fungera bra som ett komplement till fotosensibilisering med 5-ALA eftersom att det var möjligt att se Ramanband associerade med hjärnvävnad när vävnaden hade belysts med blått ljus.
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Hirabayashi, Hidehiro. "Stereotactic imaging in functional neurosurgery." Doctoral thesis, Umeå universitet, Klinisk neurovetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-55141.
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Background: The birth of stereotactic functional neurosurgery in 1947 was to a great extent dependent on the development of ventriculography. The last decades have witnessed a renaissance of functional stereotactic neurosurgery in the treatment of patients with movement disorders. Initially, these procedures were largely based on the same imaging technique that had been used since the birth of this technique, and that is still used in some centers. The introduction of new imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) provided new potentials, but also new challenges for accurate identification and visualisation of the targets in the basal ganglia and the thalamus with an urge to thoroughly evaluate and optimize the stereotactic targeting technique, as well as evaluate accurately in stereotactic space the location and extent of stereotactic Radiofrequency (RF) lesions and the position of deep brain stimulation (DBS) electrodes. Aims: To study the differences between CT and MRI regarding indirect atlas coordinates in thalamic and pallidal procedures and to evaluate and validate visualisation of the pallidum and the subthalamic nucleus in view of direct targeting irrespective of atlas-derived coordinates. Furthermore, to evaluate the contribution of RF parameters on the size of stereotactic lesions, as well as the impact of size and location on clinical outcome. Method: The coordinates in relation to the landmarks of the 3rd ventricle of the targets in the pallidum and ventrolateral thalamus were compared between CT and MRI in 34 patients. In another 48 patients direct visualization of the pallidum was evaluated and compared to indirect atlas based targeting. The possibility and versatility of visualizing the Subthalamic Nucleus (STN) on short acquisition MRI were evaluated in a multicentre study, and the use of alternative landmarks in identification of the STN was demonstrated in another study. In 46 patients CT and MRI were compared regarding the volume of the visible RF lesions. The volume was analysed with regard to coagulation parameters, and the location and size of the lesions were further evaluated concerning the clinical outcome. Results:Minor deviations were seen between MRI and CT coordinates of brain targets. The rostro-caudal direction of these deviations were such that they would be easily accounted for during surgery, why MRI can obviate the need for CT in these procedures. MRI using a proton density sequence provided detailed images of the pallidal structures, which demonstrated considerable inter-individual variations in relation to the landmarks of the 3rd ventricle. By using a direct visualization of the target, each patient will act as his or her own atlas, avoiding the uncertainties of atlas-based targeting. The STN could be visualized on various brands of MRI machines in 8 centers in 6 countries with good discrimination and with a short acquisition time, allowing direct visual targeting. The same scanning technique could be used for postoperative localization of the implanted electrodes. In cases where the lateral and inferior borders of the STN cannot be easily distinguished on MRI the Sukeroku sign and the dent internal-capsule-sign signs might be useful. The volume of a stereotactic RF lesion could be as accurately assessed by CT as by MRI. The lesion´s size was most strongly influenced by the temperature used for coagulation. The lesions´ volumes were however rather scattered and difficult to predict in the individual patient based solely on the coagulation parameters. For thalamotomy, the results on tremor was not related to the lesion´s volume. For pallidotomy, larger and more posterior-ventral lesions had better effect on akinesia while effects on tremor and dyskinesias were not related to size or location of the lesions. Conclusions: The minor deviations of MRI from CT coordinates can be accounted for during surgery, why MRI can obviate the need of CT in these procedures. Direct visualized targeting on MRI of the pallidum is superior to atlas based targeting. The targets in the pallidum and the STN, as well as the location of the electrodes, can be well visualized with short acquisition MRI. When borders of the STN are poorly defined on MRI the Sukeroku sign and the dent internal-capsule-sign signs proved to be useful. The volumes of RF lesions can be accurately assessed by both stereotactic thin slice CT and MRI. The size of these lesions is most strongly influenced by the temperature of coagulation, but difficult to predict in the individual patient based on the coagulation parameters. Within certain limits, there were no clear relationships between lesions´ volume and location and clinical effects of thalamotomies and pallidotomies.
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Diepenbrock, Stefan, Jörg-Stefan Praßni, Florian Lindemann, Hans-Werner Bothe, and Timo Ropinski. "Interactive Visualization Techniques for Neurosurgery Planning." University of Münster, Germany, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-92863.
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We present concepts for pre-operative planning of brain tumor resections. The proposed system uses a combination of traditional and novel visualization techniques rendered in real-time on modern GPUs in order to support neurosurgeons during intervention planning. A set of multimodal 2D and 3D renderings conveys the relation between the lesion and the various structures at risk and also depicts data uncertainty. To facilitate efficient interactions while providing a comprehensible visualization, all employed views are linked. Furthermore, the system allows the surgeon to interactively define the access path by clicking in the 3D views as well as to perform distance measurements in 2D and 3D.Short paper
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Kochan, Martin. "Enhancing registration for image-guided neurosurgery." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10045247/.
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Pharmacologically refractive temporal lobe epilepsy and malignant glioma brain tumours are examples of pathologies that are clinically managed through neurosurgical intervention. The aims of neurosurgery are, where possible, to perform a resection of the surgical target while minimising morbidity to critical structures in the vicinity of the resected brain area. Image-guidance technology aims to assist this task by displaying a model of brain anatomy to the surgical team, which may include an overlay of surgical planning information derived from preoperative scanning such as the segmented resection target and nearby critical brain structures. Accurate neuronavigation is hindered by brain shift, the complex and non-rigid deformation of the brain that arises during surgery, which invalidates assumed rigid geometric correspondence between the neuronavigation model and the true shifted positions of relevant brain areas. Imaging using an interventional MRI (iMRI) scanner in a next-generation operating room can serve as a reference for intraoperative updates of the neuronavigation. An established clinical image processing workflow for iMRI-based guidance involves the correction of relevant imaging artefacts and the estimation of deformation due to brain shift based on non-rigid registration. The present thesis introduces two refinements aimed at enhancing the accuracy and reliability of iMRI-based guidance. A method is presented for the correction of magnetic susceptibility artefacts, which affect diffusion and functional MRI datasets, based on simulating magnetic field variation in the head from structural iMRI scans. Next, a method is presented for estimating brain shift using discrete non-rigid registration and a novel local similarity measure equipped with an edge-preserving property which is shown to improve the accuracy of the estimated deformation in the vicinity of the resected area for a number of cases of surgery performed for the management of temporal lobe epilepsy and glioma.
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Greger, Klaus. "OligoChannel spectral analysis in stereotactic laser neurosurgery." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=967776384.
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Livingstone, Alison A. "Neuropsychological outcome following neurosurgery for mental disorder." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/28446.
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Neurosurgery for mental disorder (NMD) continues to exist as one of a range of treatments available to individuals who experience severe and intractable psychiatric illness. Historically, this particular use of ablative neurosurgery has attracted a considerable amount of interest and controversy. Despite modern advances in both technical procedure and understanding of the disorders for which NMD is indicated, the irreversibility of these procedures continues to attract attention from both public and professional groups alike. To date, indisputable evidence regarding the efficacy and frequency of adverse effects has not been established. Therefore, the primary aim of the present study was to investigate the neuropsychological outcome following neurosurgery for mental disorder. In light of previous research, the specific aims were designed to elucidate the impact of such procedures on aspects of both general and executive functioning, through means of clinical and computerised neuropsychological assessments. As such, pre- and post-operative performance scores of an entire population of surgical candidates at a national centre for the provision of NMD were examined. The principle investigation focussed on a group of 22 individuals of mixed diagnostic categories, all of whom had undergone treatment by anterior capsulotomy. Within-subjects comparisons revealed the overall stability of post-operative performance as measured by tests of general cognitive and executive function, at follow-up periods of two weeks, one year, and in a sub-group of individuals, two and a half years post-operatively. A small number of statistically significant improvements and impairments were noted, and along with the general trend of improvement observed at long term follow-up, are discussed in the light of related research.
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Clonda, Diego. "Automatic thalamic labeling for image-guided neurosurgery." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0007/MQ44150.pdf.
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Munger, Patrice. "Accuracy considerations in MR image-guided neurosurgery." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22780.
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This thesis studies various aspects of the accuracy issue in image-guided neurosurgery (IGNS). Factors such as registration, MR geometrical distortions and accuracy of digitizing device, are theoretically described in a general model of IGNS.The means of registering the patient to its image data is then studied, starting with the definition of registration error. Computer simulations of registration by homologous point matching are described along with a clinical study comparing homologous point matching and surface matching registration methods.
A 3-D MR geometrical distortion experiment performed on a stereotactic frame is presented. These measurements demonstrate the discrepancy that can be observed in the geometry of the frame when imaged with differing read-out gradient directions, and quantitatively evaluate the geometrical distortion associated with the image of the frame of known geometry.
Since geometrical distortion of MR images can adversely affect the accuracy of IGNS, the three-point-Dixon MR pulse sequence is evaluated as a means of estimating the magnetic field inhomogeneity, and hence potential geometrical errors in images.
Finally, an experimental comparison of mechanical and optical localizing devices is described, resulting in a quantitative estimate of the precision and accuracy of both systems.
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François, Quentin. "Microrobot guidance through neuronavigation for microrobotic neurosurgery." Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS314.
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Tandis que les outils neurochirurgicaux, dont le diamètre est supérieur à 1.2mm, permettent uniquement de se déplacer en ligne droite, les systèmes microrobotiques deviennent de plus en plus robustes [...]While neurosurgical tools, whose diameter are above 1.2 mm, allow neurosurgeons to move only in a straight line, the microrobotic field has seen huge advances [...]
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Vathalloor, Mathew Manoj. "Neuron guidance and nano-neurosurgery using optical tools." Doctoral thesis, Universitat Politècnica de Catalunya, 2009. http://hdl.handle.net/10803/33075.
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Akram, Harith. "Application of MRI connectivity in stereotactic functional neurosurgery." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10052005/.
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This thesis examines potential applications of advanced MRI-connectivity studies in stereotactic functional neurosurgery. Several new analysis methodologies are employed to: (1) build predictive models of DBS surgery outcome; (2) refine the surgical target and (3) help build a better understanding of the pathogenesis of the treated conditions and the mechanism of action of DBS therapy. The experimental component is divided into three main parts focusing on the following pathologies: (1) Parkinson’s disease (PD), (2) tremor and (3) trigeminal autonomic cephalalgias (TAC). Section I: In the first experiment (chapter 3), resting state fMRI was used to find radiological biomarkers predictive of response to L-DOPA in 19 patients undergoing subthalamic nucleus (STN) DBS for PD. A greater improvement in UPDRS-III scores following L-DOPA administration was characterized by higher resting state functional connectivity (fcMRI) between the prefrontal cortex and the striatum (p=0.001) and lower fcMRI between the pallidum (p=0.001), subthalamic nucleus (p=0.003) and the paracentral lobule. In the second experiment (chapter 4), structural (diffusion) connectivity was used to map out the influence of the hyperdirect pathways on outcome and identify the therapeutic ‘sweet spots’ in twenty PD patients undergoing STN-DBS. Clusters corresponding to maximum improvement in symptoms were in the posterior, superior and lateral portion of the STN. Greater connectivity to the primary motor area, supplementary motor area and prefrontal cortex was predictive of higher improvement in tremor, bradykinesia and rigidity, and rigidity respectively. The third experiment (chapter 5) examined pyramidal tract (PT) activation in 20 PD patients with STN-DBS. Volume of tissue activation (VTA) around DBS contacts were modelled in relation to the PT. VTA/ PT overlap predicted EMG activation thresholds. Sections II: Pilot data suggest that probabilistic tractography techniques can be used to segment the ventrolateral (VL) and ventroposterior (VP) thalamus based on cortical and cerebellar connectivity in nine patients who underwent thalamic DBS for tremor (chapter 6). The thalamic area, best representing the ventrointermedialis nucleus (VIM), was connected to the contralateral dentate cerebellar nucleus. Streamlines corresponding to the dentato-rubro-thalamic tract (DRT) connected M1 to the contralateral dentate nucleus via the dentato-thalamic area. Good response was seen when the active contact’s VTA was in the thalamic area with the highest connectivity to the contralateral dentate nucleus. Section III: The efficacy and safety of DBS in the ventral tegmental area (VTa) in the treatment of chronic cluster headache (CH) and short lasting unilateral neuralgiform headache attacks (SUNA) were examined (chapters 7 and 8). The optimum stimulation site within the VTa that best controls symptoms was explored (chapter 9). The average responders’ deep brain stimulation activation volume lay on the trigemino-hypothalamic tract, connecting the trigeminal system and other nociceptive brainstem nuclei, with the hypothalamus, and the prefrontal and mesial temporal areas.
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Daga, P. "Towards efficient neurosurgery : image analysis for interventional MRI." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1449559/.
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Interventional magnetic resonance imaging (iMRI) is being increasingly used for performing imageguided neurosurgical procedures. Intermittent imaging through iMRI can help a neurosurgeon visualise the target and eloquent brain areas during neurosurgery and lead to better patient outcome. MRI plays an important role in planning and performing neurosurgical procedures because it can provide highresolution anatomical images that can be used to discriminate between healthy and diseased tissue, as well as identify location and extent of functional areas. This is of significant clinical utility as it helps the surgeons maximise target resection and avoid damage to functionally important brain areas. There is clinical interest in propagating the pre-operative surgical information to the intra-operative image space as this allows the surgeons to utilise the pre-operatively generated surgical plans during surgery. The current state of the art neuronavigation systems achieve this by performing rigid registration of pre-operative and intra-operative images. As the brain undergoes non-linear deformations after craniotomy (brain shift), the rigidly registered pre-operative images do not accurately align anymore with the intra-operative images acquired during surgery. This limits the accuracy of these neuronavigation systems and hampers the surgeon’s ability to perform more aggressive interventions. In addition, intra-operative images are typically of lower quality with susceptibility artefacts inducing severe geometric and intensity distortions around areas of resection in echo planar MRI images, significantly reducing their utility in the intraoperative setting. This thesis focuses on development of novel methods for an image processing workflow that aims to maximise the utility of iMRI in neurosurgery. I present a fast, non-rigid registration algorithm that can leverage information from both structural and diffusion weighted MRI images to localise target lesions and a critical white matter tract, the optic radiation, during surgical management of temporal lobe epilepsy. A novel method for correcting susceptibility artefacts in echo planar MRI images is also developed, which combines fieldmap and image registration based correction techniques. The work developed in this thesis has been validated and successfully integrated into the surgical workflow at the National Hospital for Neurology and Neurosurgery in London and is being clinically used to inform surgical decisions.
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Depaoli, Damon, and Damon Depaoli. "Guiding deep brain stimulation neurosurgery with optical spectroscopy." Doctoral thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/37637.
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Savoir différiencier les différentes types de tissus représente un aspect important lors d’interventions médicales, que ce soit pour aider au diagnostic d’une maladie ou pour le guidage chirurgical. Il est généralement très difficile de distinguer les tissus sains des tissus pathologiques à l’oeil nu et la navigation chirurgicale peut parfois être difficile dans les grands organes où la structure ciblé se trouve enfouie profondément. De nouvelles méthodes susceptibles d’accroître la réussite de telles interventions médicales suscitent actuellement de l’intérêt chez les professionnels de la santé. La spectroscopie optique, en analysant les interactions lumière-tissu dans une plage spectrale définie, est un outil permettant de différencier les tissus avec une résolution et une sensibilité bien supérieures à celles de l’oeil humain. Tout au long de cette thèse, je détaillerai comment la spectroscopie optique a été utilisée pour créer et améliorer un système de guidage optique utilisé pour la stimulation cérébrale profonde en neurochirurgie, en particulier pour le traitement de la maladie de Parkinson. Pour commencer, je montrerai comment les informations spectroscopiques peuvent fournir une rétroaction peropératoire en temps réel à un neurochirurgien, au cours de la phase d’implantation de la procédure, avec une sonde qui n’induit aucune invasion supplémentaire. Je présenterai l’investigation de deux modalités spectroscopiques différentes pour la discrimination tissulaire pour le guidage, soit la spectroscopie à réflectance diffuse et la spectroscopie de diffusion Raman anti-Stokes cohérente. Les avantages et les inconvénients des deux techniques, ainsi que leurs aptitude à la traduction prometteuse pour cette application seront abordés. Par la suite, je présenterai une nouvelle technique d’analyse de données pour extraire l’oxygénation des tissus à partir de spectres de réflectance diffus dans le but d’améliorer la précision de mesure en spectroscopie rétinienne et ultimement de porter un diagnostique. Bien que conçu pour la rétine, l’algorithme peut également être utilisé pour analyser les spectres acquis lors d’une neurochirurgie afin de fournir des informations à la fois discriminantes et diagnostiques. Finalement, je montrerai des preuves de diffusion anisotrope de la lumière dans les axones myélinisés de la moelle épinière et discuterai des conséquences que cela pourrait avoir sur les simulations actuelles de la propagation des photons dans le cerveau, qui feront partie intégrante d’un guidage optique efficace.Savoir différiencier les différentes types de tissus représente un aspect important lors d’interventions médicales, que ce soit pour aider au diagnostic d’une maladie ou pour le guidage chirurgical. Il est généralement très difficile de distinguer les tissus sains des tissus pathologiques à l’oeil nu et la navigation chirurgicale peut parfois être difficile dans les grands organes où la structure ciblé se trouve enfouie profondément. De nouvelles méthodes susceptibles d’accroître la réussite de telles interventions médicales suscitent actuellement de l’intérêt chez les professionnels de la santé. La spectroscopie optique, en analysant les interactions lumière-tissu dans une plage spectrale définie, est un outil permettant de différencier les tissus avec une résolution et une sensibilité bien supérieures à celles de l’oeil humain. Tout au long de cette thèse, je détaillerai comment la spectroscopie optique a été utilisée pour créer et améliorer un système de guidage optique utilisé pour la stimulation cérébrale profonde en neurochirurgie, en particulier pour le traitement de la maladie de Parkinson. Pour commencer, je montrerai comment les informations spectroscopiques peuvent fournir une rétroaction peropératoire en temps réel à un neurochirurgien, au cours de la phase d’implantation de la procédure, avec une sonde qui n’induit aucune invasion supplémentaire. Je présenterai l’investigation de deux modalités spectroscopiques différentes pour la discrimination tissulaire pour le guidage, soit la spectroscopie à réflectance diffuse et la spectroscopie de diffusion Raman anti-Stokes cohérente. Les avantages et les inconvénients des deux techniques, ainsi que leurs aptitude à la traduction prometteuse pour cette application seront abordés. Par la suite, je présenterai une nouvelle technique d’analyse de données pour extraire l’oxygénation des tissus à partir de spectres de réflectance diffus dans le but d’améliorer la précision de mesure en spectroscopie rétinienne et ultimement de porter un diagnostique. Bien que conçu pour la rétine, l’algorithme peut également être utilisé pour analyser les spectres acquis lors d’une neurochirurgie afin de fournir des informations à la fois discriminantes et diagnostiques. Finalement, je montrerai des preuves de diffusion anisotrope de la lumière dans les axones myélinisés de la moelle épinière et discuterai des conséquences que cela pourrait avoir sur les simulations actuelles de la propagation des photons dans le cerveau, qui feront partie intégrante d’un guidage optique efficace.
Differentiating tissue types is an important aspect of guiding medical interventions whether it be for disease diagnosis or for surgical guidance. However, diseased and healthy tissues are often hard to discriminate by human vision alone and surgical navigation can be difficult to accomplish in large organs where the target structure lies deep within the body. New methods that can increase certainty in such medical interventions are therefore of great interest to healthcare professionals. Optical spectroscopy is a tool which can be exploited to probe discriminatory information in tissue by analyzing light-tissue interactions with a spectral range, resolution and sensitivity much greater than the human eye. Throughout this thesis, I will explain how I have leveraged optical spectroscopy to create, and improve, an optical guidance system for deep brain stimulation neurosurgery, specifically for the treatment of Parkinson’s disease. I will begin by describing how spectroscopic information can provide real-time feedback to a surgeon during the procedure, in the hopes of ultimately improving treatment outcome. To this end, I will present the investigation of two different spectroscopic modalities for optical guidance: diffuse reflectance spectroscopy, and coherent anti-Stokes Raman scattering spectroscopy. The advantages and disadvantages of both techniques will be discussed along with their promising translatability for this application. Following this, I will present a novel data analysis technique for extracting the tissue oxygenation from diffuse reflectance spectra with the aim of improved diagnostic information in retinal spectroscopy. While designed for the retina, the algorithm can also be used to analyze spectra acquired during a neurosurgery to provide both discriminatory and diagnostic information. Lastly, I will show evidence of anisotropic light scattering in the myelinated axons of the spinal cord and discuss the implications this may have on current photon propagation simulations in the brain, which will be integral for effective optical guidance.
Differentiating tissue types is an important aspect of guiding medical interventions whether it be for disease diagnosis or for surgical guidance. However, diseased and healthy tissues are often hard to discriminate by human vision alone and surgical navigation can be difficult to accomplish in large organs where the target structure lies deep within the body. New methods that can increase certainty in such medical interventions are therefore of great interest to healthcare professionals. Optical spectroscopy is a tool which can be exploited to probe discriminatory information in tissue by analyzing light-tissue interactions with a spectral range, resolution and sensitivity much greater than the human eye. Throughout this thesis, I will explain how I have leveraged optical spectroscopy to create, and improve, an optical guidance system for deep brain stimulation neurosurgery, specifically for the treatment of Parkinson’s disease. I will begin by describing how spectroscopic information can provide real-time feedback to a surgeon during the procedure, in the hopes of ultimately improving treatment outcome. To this end, I will present the investigation of two different spectroscopic modalities for optical guidance: diffuse reflectance spectroscopy, and coherent anti-Stokes Raman scattering spectroscopy. The advantages and disadvantages of both techniques will be discussed along with their promising translatability for this application. Following this, I will present a novel data analysis technique for extracting the tissue oxygenation from diffuse reflectance spectra with the aim of improved diagnostic information in retinal spectroscopy. While designed for the retina, the algorithm can also be used to analyze spectra acquired during a neurosurgery to provide both discriminatory and diagnostic information. Lastly, I will show evidence of anisotropic light scattering in the myelinated axons of the spinal cord and discuss the implications this may have on current photon propagation simulations in the brain, which will be integral for effective optical guidance.
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Majithia, Vishal. "Intersubject surface mapping with nonrigid registration for neurosurgery." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013325.
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Aswapathi, Ramesh Ganesh Gautham. "Set Screw Break-Off Study In Spinal Neurosurgery." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1885431371&sid=7&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Eriksson, Ola. "Characterisation and modelling of radiofrequency lesioning in functional neurosurgery /." Linköping : Univ, 2001. http://www.bibl.liu.se/liupubl/disp/disp2001/tek693s.pdf.
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Mjoli, Ntethelelo. "Brain arteriovenous malformations presenting with haemorrhage." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/2886.
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Semple, Patrick Lyle. "Pituitary apoplexy : can histopathology, radiological imaging and predisposing factors be used in predicting outcome?" Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/2890.
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Includes abstract.Includes bibliographical references (leaves 98-112).
Pituitary apoplexy is an uncommon, yet potentially fatal illness, usually the result of infarction, hemorrhage or a combination of both in a pituitary tumor. The management of pituitary apoplexy consists of replacement therapy and in the majority of patients, surgical decompression, although some cases may be treated conservatively. Up to now no study has attempted to separate the two histopathological types of pituitary apoplexy or to analyze their clinical and radiological significance on presentation and outcome.
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Leng, Jeanette Anne. "Neuropsychological sequelae of paediatric posterior fossa brain tumours : the effect on quality of life." Doctoral thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/2885.
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Padayachy, Llewellyn. "Ultrasound as a non-invasive diagnostic tool in paediatric neurosurgery : relationship between the optic nerve sheath diameter (ONSD) and intracranial pressure (ICP)." Doctoral thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/16787.
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Includes bibliographical referencesBackground: Assessment of intracranial pressure (ICP) is an essential aspect in the management of most neurosurgical conditions in children. While invasive ICP monitoring is considered the criterion standard, the need for a reliable, non-invasive, easy-to-use and accurate method to detect and monitor raised ICP has inspired the development of many useful techniques. The present study examined the relationship between transorbital ultrasound measurement of the optic nerve sheath diameter (ONSD) and invasively measured ICP in children, as well as the influence of relevant physiological and demographic variables on this relationship. Methodology: ONSD measurement was performed using a high frequency, small footprint linear array probe, and prior to invasive ICP measurement. All patients were under general anaesthesia and being mechanically ventilated. Physiological variables including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse rate, temperature, respiratory rate and end tidal carbon dioxide (ETCO2) level were recorded at the time of ONSD measurement. The ONSD measurements were analysed for repeatability, intra- and inter-observer variability as well for correlation between images acquired in different planes and those obtained from either eye. The diagnostic accuracy of ONSD measurement for detecting ICP at different thresholds of 20, 15, 10 and 5 mmHg was analysed. This analysis included evaluation of age-related thresholds for defining different ONSD cut-off values in children. Dynamic image acquisition was performed and analysed to evaluate the relevant pulsatile motion of the ONS as a marker of the sheath stiffness. Results: One hundred and seventy four children undergoing diagnostic or therapeutic surgical procedures were included in this study. ONSD measurement demonstrated good correlation with ICP across the entire patient cohort (r = 0.66, p < 0.001), but was better in children > 1 year or with a closed anterior fontanelle (AF) (r = 0.7, p < 0.001). Age above and below 1 year was found to be an appropriate age threshold for defining two different sets of ONSD cut-off values. The study however, supported using patency of the AF as a stronger clinical marker for describing different ONSD cut-off values in children. The second part of this work described a dynamic technique for analysing the pulsatile motion of the ONS. Analysis of the deformability index (DI) as an indirect marker of ONS stiffness, revealed a statistically significant relationship with ICP (sensitivity of 90%, specificity of 87% for detecting ICP ≥ 20 mmHg). Conclusion: Measurement of the ONSD is a sensitive surrogate marker of raised ICP, but demonstrated poorer specificity. This relationship was more reliable in older children, particularly when the AF was closed. Analysis of the dynamic characteristics of the ONS appeared to provide useful additional information as an independent marker, and may contribute to our overall understanding of ONSD measurement in raised ICP.
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Figaji, Anthony A. "Multimodality monitoring in paediatric severe traumatic brain injury : the contributions of brain oxygen, transcranial doppler and autoregulation monitoring to conventional methods on monitoring." Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/2882.
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Includes abstract.Includes bibliographical references (p. 175-218).
Traumatic brain injury (TBI) is a highly complex clinical condition in the most complex organ of the body. The foundation of care of the patient with severe TBI is the prevention of secondary insults to the brain. This relies on conventional monitoring tools to identify patients at risk, but often these may fail to detect important secondary insults. Moreover, the therapies that are used commonly in the critical care environment all have potential adverse effects, many of which may not be evident. TBI treatment in children is further complicated by changing thresholds with age, and the much smaller evidence base compared to their adult counterparts.
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Nair, Omesan. "Profiling medulloblastoma and juvenile pilocytic astrocytoma brain tumours in a South African paediatric cohort." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/26896.
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Brain tumours in children are one of the most challenging diseases to treat, and so outcomes are variable and often lacking. There are currently no reliable data of presentation of disease, the spectrum of tumours treated, how these are treated, and what the outcomes are for children in South Africa, and certainly no molecular biology data. In this respect, this thesis investigated the two commonest types of childhood brain tumour, the highly malignant Medulloblastoma (MB) and the generally less aggressive Juvenile Pilocytic Astrocytoma (JPA) with relation to their molecular biology and their clinical correlates to begin to address this gap and build capacity for further molecular-based studies in an African context. The study design in this thesis takes a systematic approach and is structured into MB and JPA biochemical characterisation followed by 4 studies of their respective proteomic profiles. The study design involved creating appropriate patient cohorts and determining sample characteristics for interpretation of results. The statistical power achieved in this thesis showed a minimum of 2-fold difference for a power greater than 0.8 in each case. Proteomic clustering was used to validate or delineate any discrepancies in subtype assignments for MB. Molecular profiles together with proteomic data of MB and JPA cases in this thesis provide evidence for some novel molecular pathways, proteins and peptides associated with pathogenesis. This work therefore provides extensive data that is hypothesis generating for further studies that could build upon molecular understanding in a South African and larger African context.
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Fieggen, Anthony Graham. "The Cape Town Stereotactic pointer clinical development and Applications." Doctoral thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/2881.
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This dissertation describes the development and clinical use of a novel stereotactic neurosurgical system, the Cape Town Stereotactic Pointer (CTSP). This system has four main components; a halo containing three fiducials also serves as the platform for a tripod pointing device which is set with the aid of a 3D phantom or a printed setting diagram, and software which enables transformation of imaging space into patient space. Laboratory tests indicated an application accuracy of 1.9 +/- 0.6mm using the 3D phantom to set the tripod. From the first clinical application, the system underwent a series of iterations which could broadly be divided into four successive phases of refinement. This took place over a six year period, encompassing one hundred patients who underwent 115 stereotactic procedures. Indications for surgery included biopsy (62.6%), aspiration (15.7%) and cannulation (21.7%) and the surgical objective was realized in 101/109 cases (92.7%). Given the fact that six of the eight failures represented errors of surgical judgment that could not be ascribed to the device, and each of two system errors resulted in a significant modification to the system, the CTSP demonstrated a satisfactory level of accuracy in the clinical setting. This was accomplished at an acceptable complication rate, with one death five days after surgery attributable to a stereotactic procedure (mortality 0.9%) and major morbidity in two cases (1.7%); thirteen patients experienced minor complications, all of which proved to be transient (11.3%). A simple protocol for use of the CTSP evolved over the course of this study, making it easier for neurosurgeons from varying backgrounds to introduce stereotaxis into their practice with the help of this system. In addition to satisfactory levels of clinical reliability and safety, the system was versatile and also well tolerated by patients. It is hoped that the CTSP provides a costeffective alternative for neurosurgeons working in under-resourced settings. Sixty units of the production version of the CTSP have been sold and the system is now in use in ten countries.
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Padayachy, L. C. "The prevalence of cerebral hypoxia/ischemia in pediatric severe traumatic brain injury." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/2887.
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Pillay, Robin. "Adult neoplastic spinal cord compression." Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/2888.
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Bibliography : leaves 91-107.Spinal cord compression ( SCC ) constitutes a neurological emergency, and if left untreated, can result in permanent irreversible neurological dysfunction. Disabilities can range from mild weakness to complete quadriplegia with the inherent associated mental, physical and emotional suffering .The burden of cost to the individual and community is enormous.
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Figaji, Anthony Aaron. "Decompressive craniectomy in children with traumatic brain injury." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/2883.
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Includes bibliographical references (leaves 58-72).Although the conventional role of the operation was that of a salvage procedure when medical therapy failed in the treatment of raised intracranial pressure (ICP), two important concepts have emerged in the recent literature that appear to challenge that approach. In addition to the lack of evidence supporting benefit from current forms of treament, evidence from diverse studies that use data from magnetic resonance images, cerebral owygenation and cerebral blood flow measurements have highlighted potential adverse effects that may occur with these therapies.
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Wegoye, Emmanuel. "Radiotherapy for head and neck paragangliomas: A 10 year retrospective review 2005-2014 at Groote Schuur Hospital and UCT Private academic hospital." Master's thesis, Faculty of Health Sciences, 2019. http://hdl.handle.net/11427/30840.
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Objective. Over the last two decades there has been increasing evidence that radiosurgery and radiotherapy management of skull-base paragangliomas is as effective as microsurgical resection and carries less morbidity. This 10 year retrospective review of 24 patients in a single institution, treated over 10 years assesses tumour control rates and morbidity associated with radiosurgery and radiotherapy treatment. Method. Patients with a radiological diagnosis of skull-base paragangliomas were treated with different techniques of stereotactic and image-guided radiotherapy delivering hypo fractionated irradiation. Techniques used included conventional radiotherapy or intensity modulated radiotherapy (IMRT), dynamic arc (DA) and volumetric modulated arc therapy (VMAT). Analysis of local tumour control was performed using RECIST criteria and the KaplanMeier method. 69% of patients received 14-16gy in 1-3 fractions while 31% received 48- 50gy in 25 fractions. Radiation-associated toxicity was graded according to the commonly used Radiation therapy Oncology group (RTOG) toxicity criteria. Results. 24 patients with skull-base paragangliomas were treated with a median follow up of 43 months. One patient lost to follow up and was excluded. Tumour control was achieved in 96% of patients. 76% of patients treated reported no radiation associated toxicity. 24% of patients had some radiation associated toxicity: the conventional group 12%, stereotactic radiosurgery 8% and stereotactic radiotherapy 4%. 43% of patients in the conventional group had progression of hearing loss in the affected ear. One patient in the radiosurgery group developed osteonecrosis of the temporal bone at 5 year follow up. Conclusion. Radiosurgery and radiotherapy are efficacious in achieving tumour control with minimal morbidity. Tumour control rates in the study are similar to control rates in literature. Radiation associated toxicities are mainly minor. Study is limited by the retrospective nature and limited duration of follow up.
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Thompson, Crispin. "Hyperextension injury of the cervical spine with central cord syndrome." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/2892.
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Taylor, Allan Grant. "Advantages of delayed ventriculoperitoneal shunting in post haemorrhagic hydrocephalus seen in low birth weight infants." Master's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/26759.
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INTRODUCTION: The incidence of intraventricular hemorrhage (IVH) in very low birth weight infants is between 25 and 50%. Approximately 13-60% of these patients will develop progressive post hemorrhagic hydrocephalus (PHH) and of these 22- 70% will require CSF diversion. The most common therapeutic intervention is insertion of a ventriculoperitoneal shunt but there is considerable controversy surrounding the timing of the operation. Most authors promote early surgery to prevent secondary injury from hydrocephalus but it was our impression that this was associated with a higher incidence of shunt complications. METHOD: The incidence of shunt complications in 36 patients shunted for PHH were retrospectively reviewed. Patients were treated at Red Cross Children's Hospital over an 8 year period. RESULTS: Nine (25%) of the 36 patients required shunt revision for obstruction, seven required revision during the initial admission. Shunt infection occurred in 4 patients (11 %) all during the initial hospital admission. Four patients died, one from a shunt related complication. There was a clear relationship between the timing of surgery and the incidence of complications (chi square test p,0.01 ). Nineteen patients underwent surgery before 5 weeks of age and 9 developed early shunt complications. Of those shunted after 5 weeks none had an early complication. Groups were matched for weight and grade of IVH. DISCUSSION: A possible explanation for these results is that shunt complications are related to the quantity of blood present in the CSF at the time of shunting. A short delay before intervention is recommended in an effort to reduce the morbidity of shunt complications.
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Enslin, Johannes Marthinus Nicolaas. "Outcomes of decompressive craniectomy in adults with severe traumatic brain injury: the Groote Schuur Hospital experience." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13110.
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Includes bibliographical references.Object: The aim of this study was to assess outcome following decompressive craniectomy in adults with severe traumatic brain injury (TBI) in a South African neurosurgical unit. Methods: During a 78 month period (January 2005 – June 2011), 76 patients that underwent decompressive craniectomy for TBI in an attempt to lower raised intracranial pressure (ICP) were reviewed . All were older than 14 years and mass lesions were included. Thirty nine point four percent of the patients sustained blunt, low velocity injuries to the head and 19% were involved in motor vehicle accidents. Unilateral hemi-craniectomies were carried out in 81% of patients and 54 (75%) were done as primary decompressive craniectomies. Survivors were followed up for a period of at least six months and functional outcomes were measured using the Glasgow outcomes score. To simplify outcomes the patients were then dichotomised into outcome groups of good (GOS 4 and 5 ), and poor (GOS 1- 3). Results: At six months follow up 24 patients (33.3%) had a good outcome (GOS 4 or 5) and 48 patients (66.7%) had a poor outcome (GOS 1- 3). 32 patients (44.4%) died (GOS 1). There were 16 survivors in the poor group. Sixty percent o f survivors had a good outcome after decompressive craniectomy. Eighteen patients underwent secondary decompressive craniectomies and 54 (75%) primary decompressive craniectomies. Thirty - five percent of patients that underwent primary decompressive cranie ctomy had a good outcome, versus 38% in the secondary decompression group. Mortality was slightly higher in the primary decompression group (43%) than the secondary group (33%) . Factors that showed significant correlation with outcome were age, admission GCS and good response of ICP to decompressive craniectomy. Complications were encountered in 18% of patients with sepsis being the most common (11%). Conclusion: Decompressive craniectomy was associated with a functional outcome that was better than exp ected in patients with severe TBI and should still form part of salvage therapy in adults with TBI and elevated ICP.
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Roytowski, David. "Intracranial pressure monitoring as an early predictor of third ventriculostomy outcome." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/5935.
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Mankahla, Ncedile. "The Changing Face of Craniopharyngioma Treatment in Young Children and its Challenges at a Single Centre in a Developing World Context." Master's thesis, Faculty of Health Sciences, 2019. http://hdl.handle.net/11427/31106.
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Objective: To retrospectively review our institutional experience with the
treatment of paediatric craniopharygiomas and assess the evolution in
management and influence on patient outcomes.
Patients and Methods: A retrospective review from January 1995 to
December 2015 of children age <14 treated at a single institution. Data
collected included admission clinical features, endocrine function, surgery
performed, surgical outcome, intracystic therapy and radiotherapy. Long-term
functional outcome was calculated considering hormonal dependence, level of
independence and schooling.
Results: There were 41 patients with a mean age of 84.2 months: 57% were
female. Primary surgical resection was performed in 36 patients: 80.5% had
subtotal resection, 11% had gross total resection and the rest had biopsy
only. Of surgical approaches, 60,7% had pterional craniotomy and 39,2%
supraorbital keyhole craniotomy. No surgical mortalities occurred but 2
patients had new post-operative neurological deficits. Stereotactic placement
of intracystic catheters transitioned to endoscopic. Intracystic treatments
transitioned from Yttrium (1) to Bleomycin (6) to Interferon Alpha (6).
Radiotherapy was given in 30 patients, median dose 54Gy. Final Wen
functional outcome was 21,8% Class I, 32% Class II and 46% Class III. There
were no early deaths in the series but 5 patients died more than 6 years after
diagnosis, mostly due to endocrine crises from poor chronic care.
Conclusion: The findings reflect a multidisciplinary team approach consisting
of maximal safe resection with radiotherapy, intracystic agents and endocrine
support. For a cohort limited to young children, our results are similar in
number and outcomes to other published series. Mortality remains low but
lifelong dependence on endocrine replacement is a significant contributor to
long-term morbidity and mortality. This has important implications for patients
referred from large distances and where primary and secondary follow up
care is poor.
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Semple, Patrick Lyle. "Severe head injuries in children." Master's thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/26252.
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The aim of this dissertation is to review the current literature on severe head injuries in children, with particular respect to epidemiology, clinical features and investigation, pathophysiology, management and outcome. In addition a retrospective study was carried out on severe head injuries at Red Cross War Memorial Children's Hospital. Finally, the findings of this study are discussed in the light of the experience of other neurosurgical and trauma centres. In this way similarities as well as features peculiar to our setting can be identified with the aim of improving the understanding and management of severe head injuries in children in the Western Cape.
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Ssenyonga, Peter Kato. "The endovascular treatment of traumatic cranio-cervical vascular injuries." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/2891.
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Ben, Husien Mohammed. "Symptomatic developmental venous anomalies." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20556.
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Developmental Venous Anomalies are a normal variant that may be associated with other cerebral vascular malformation. They have bean previously referred to Venous angiomas. DVAs are the most frequently encountered cerebral vascular malformation and their incidence is reported to be high as2.6%. DVAs are classified into two types based on draining veins. Either deep or superficial. Those that drain into sub-ependymal veins are classified as deep and those that drain into cortical pial veins are classified as superficial. The trans-cerebral veins join either the deep or superficial venous systems by crossing a varying length of the brain parenchyma. Controversy surrounds their exact clinical significance, as DVAs are rarely symptomatic. The symptoms displayed by a patient can be related to a lesion that is associated with DVAs, such as a cavernoma. To describe the patients presenting to a single unit over a 10-year period with symptoms attributable to aDVA. Out of 19 patients in the database with the diagnosis of DVA, 10 were identified where the clinical presentation was directly related to the DVA. Seven of the patients presented with haemorrhage, 6 had parenchymal bleeds and one was intraventricular. Two patients had neurological deficit, 1 was transient and one was progressive. One patient had sudden severe headache with no evidence of haemorrhage on CT scan. The age range was from 14 to 55 with a mean of 32,7 years. Four patients were male and 6 were female. Of the patients that presented with haemorrhage only one had a fistula, three other patients with haemorrhage had evidence on DSA of stenosis of the large collector vein, In the remaining 3 patients no reason for the bleed could be detected. One patient presented with left hemianopia that resolved after several hours, DSA showed minimal caput medusa with delayed filling of the collector vein. The other patient that presented with progressive neurological deficit in the form of progressive leg spasticity and dysarthria, Angiography showed a large collecting vein that drains in the jugular bulb was stenosed. The last patient that presented with sudden severe headaches, with no haemorrhage identified on CT scan, On DSA there was early filling of the DVA veins compared to other cerebral veins and two prominent posterior communicating thalamoperforating vessels were seen.
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Yoshida, Jun. "Molecular Neurosurgery Using Gene Therapy to Treat Malignant Glinoma." 名古屋大学医学部, 1996. http://hdl.handle.net/2237/6179.
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Uff, Christopher. "The evaluation of advanced ultrasound elastographic techniques in neurosurgery." Thesis, Institute of Cancer Research (University Of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543946.
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Gerard, Ian. "An analysis of tracking error in image guided neurosurgery." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=121328.
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Each year, thousands of Canadians undergo neurosurgery to areas of the brain that are critical to movement, vision, sensation, or language. Recent literature demonstrates a significantly increased survival benefit with complete resection of primary and secondary brain tumours. Image guided neurosurgery uses technology that tracks a patient and special tools simultaneously to use preoperative images in order to help guide a surgeon through the surgery. There are many different types of errors that can arise during these types of interventions related to technical, physical and biological factors. The aim of this study was to quantify some of the technical and physical factors that contribute to error in these interventions. Errors associated with tracking, tool calibration and registration between a physical object and a corresponding image were all investigated and compared to theoretical descriptions of these errors. A precision milled linear testing apparatus was constructed to perform the bulk of the measurements which were broken into three categories: the fiducial localization errors (FLE), the fiducial registration errors (FRE) and the target registration errors (TRE). The fiducial localization errors deal with errors in locating a physical point and correspond to the tracking error and tool calibration errors. The tracking error (jitter) was measured as the camera's ability to consistently report the proper location of a tool and was shown to increase in a quadratic fashion with distance normal to the camera and the jitter ranged between 0.15 mm – 0.6 mm. The tool calibration error was measured and showed to increase as a function of distance from the camera as well as distance from the reference tool with calibrations ranging from 0.2 mm – 0.7 mm for the NDI pointer and 0.2 mm – 0.8 mm for the Traxtal pointer. The fiducial registration error was investigated by registering a custom built Linear Testing Apparatus (LTA) to a corresponding image volume. The FRE was shown to improve when more points were used up until a plateau value was reached which corresponded to the total FLE. This value was on the order of 0.8 mm. The distributions of the TRE were investigated for four camera-pointer pairs and two fiducial configurations and were shown to follow a chi squared distribution with the highest error generally around fiducial points and the highest variation of the TRE also around the fiducial points. Most of the results observed in this work agreed well with the previously established theory.Chaque année, des milliers de Canadiens subissent une intervention chirurgicale à proximité de zones du cerveau qui sont essentielles au mouvement, à la vision, à la sensation ou au langage. Cela crée deux contraintes contradictoires qui doivent être équilibrées pendant la chirurgie pour chaque patient. Il faut maximiser la résection de la lésion tout en minimisant le déficit neurologique pour le patient. La neurochirurgie guidée par l'image utilise une technologie qui permet de suivre simultanément la position d'outils spéciaux et du patient pour guider le chirurgien sur des images préopératoires durant la chirurgie. Il y a plusieurs types d'erreurs qui peuvent survenir lors de ce type d'intervention. Ces erreurs sont liées à des facteurs techniques, physiques et biologiques. Le but de cette étude est de quantifier certains des facteurs techniques et physiques qui contribuent à l'imprécision de ces interventions. Les erreurs liées au suivi des outils, au calibrage des outils et au recallage entre un objet physique et une image correspondante ont tous été étudiées et comparées à leurs descriptions théoriques. Un montage de test linéaire (LTA) a été usiné avec précision pour effectuer la majeure partie des mesures qui ont été divisés en trois catégories: les FLE, les FRE et les TRE. Les FLE sont des erreurs de la localisation d'un point de vue physique et correspondent à des erreurs de suivi et des erreurs de calibrage des outils. L'erreur de suivi d'un outil (jitter) a été mesurée comme étant la capacité de l'appareil à rapporter systématiquement la position exacte d'un outil et il a été démontré qu'il augmente de façon quadratique avec la distance le long de l'axe de la caméra et que sa valeur se situe entre 0,15 mm et 0,6 mm. L'erreur de calibrage des outils a été mesurée et il a été démontré qu'elle augmente en fonction de la distance de la caméra ainsi que de la distance à de l'outil de référence avec une erreur de calibration allant de 0,2 mm - 0,7 mm pour le pointeur NDI et 0,2 mm - 0,8 mm pour le pointeur Traxtal. Le FRE a été étudié en recallant la LTA sur une image volumétrique correspondante. Il a été démontré que le FRE s'améliorer avec le nombre de points utilisés jusqu'à ce qu'une valeur de seuil ait été atteinte, valeur qui correspond au FLE total. Cette valeur est de l'ordre de 0,8 mm. Les distributions du TRE ont été étudiés pour quatre paires de caméra-pointeur et deux configurations de points et il a été démontré qu'elles suivent une distribution chi carré avec la plus grande erreur généralement autour des points de référence et la variation la plus élevée de la TRE également autour des points de référence. La plupart des résultats obtenus pour cet étude concordent avec la théorie établie précédemment.
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Morgan, Paul Simon. "Spatial distortion in MRI with application to stereotactic neurosurgery." Thesis, University of Nottingham, 1999. http://eprints.nottingham.ac.uk/13091/.
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The aim of this work was to implement a thorough method for quantifying the errors introduced to frame-based neurosurgical stereotactic procedures by the use of MRI. Chang & Fitzpatrick's reversed gradient distortion correction method was used, in combination with a phantom, to measure these errors. Spatial distortion in MR images of between 1 mm and 2 mm was measured. Further analysis showed that this typically introduced an additional error in the coordinate of the actual treatment point of 0.7 mm. The implications of this are discussed. The main source of distortion in the MR images used for stereotaxis was found to be the head ring. A comparison between imaging sequences and MR scanners revealed that the spatial distortion depends mainly on the bandwidth per pixel of the sequence rather than other differences in the imaging sequences. By comparison with a phase map distortion correction technique, the imaging parameters required to allow successful distortion correction with the reversed gradient method were identified. The most important was the use of full Fourier spin echo acquisitions. The reversed gradient correction method was applied to two contemporary EPI techniques. Considerable improvement was seen in the production of ADC maps after the images had been corrected for distortion. The method also was shown to be valid in application to BOLD fMRI data.
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Whittle, Ian Roger. "Clinical applications of somatosensory evoked potentials in pediatric neurosurgery /." Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09MD/09mdw627.pdf.
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Rofes, Adria. "Verbs and nouns in awake neurosurgery: needs and answers." Doctoral thesis, Università degli studi di Trento, 2015. https://hdl.handle.net/11572/368730.
Full textAbstract:
Awake surgery is a surgical procedure applied to people with brain tumors. Patients are kept awake during surgery to perform language tasks during electrical stimulation of cortico-subcortical brain structures. When the application of electrical pulses to the brain repeatedly triggers errors, this is taken as an indication that the area is critically involved in the language skills probed by the task, and therefore should not be removed, as this would result in postoperative language deficits. In this thesis, we focused on the role of production tasks using finite verbs and the evaluation of their ability to assess language processing in comparison with the current gold standard (i.e., object naming). As a preliminary step in the development of novel, controlled object and verb production tasks, we critically reviewed the literature. We discussed published studies that proposed intraoperative tasks requiring the production of verbs in isolation and in sentences, and we graphically represented the stimulation sites and error types that were reported in each study. Subsequently, we discussed the advantages and disadvantages of each from a cognitive neuroscience and neurolinguistic perspective. With this information in mind, we constructed and validated two naming tasks for native speakers of Italian undergoing awake surgery – an object naming task and a finite verb production task. We administered the finite verb production task and other picture naming tasks to subjects with post-stroke aphasia, and established that a task that uses finite verbs shows a strong correlation with communicative abilities in daily life. Also, we introduced and compared our standardized finite verb task in the operating theater and compared it with an object naming task. Our tests are currently and successfully used in different surgery wards in Italy and overseas. This work can be extended to other neurological populations such as stroke, dementias, and epilepsy.
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Rofes, Adria. "Verbs and nouns in awake neurosurgery: needs and answers." Doctoral thesis, University of Trento, 2015. http://eprints-phd.biblio.unitn.it/1572/1/151008Rofes_phdthesis.pdf.
Full textAbstract:
Awake surgery is a surgical procedure applied to people with brain tumors. Patients are kept awake during surgery to perform language tasks during electrical stimulation of cortico-subcortical brain structures. When the application of electrical pulses to the brain repeatedly triggers errors, this is taken as an indication that the area is critically involved in the language skills probed by the task, and therefore should not be removed, as this would result in postoperative language deficits. In this thesis, we focused on the role of production tasks using finite verbs and the evaluation of their ability to assess language processing in comparison with the current gold standard (i.e., object naming). As a preliminary step in the development of novel, controlled object and verb production tasks, we critically reviewed the literature. We discussed published studies that proposed intraoperative tasks requiring the production of verbs in isolation and in sentences, and we graphically represented the stimulation sites and error types that were reported in each study. Subsequently, we discussed the advantages and disadvantages of each from a cognitive neuroscience and neurolinguistic perspective. With this information in mind, we constructed and validated two naming tasks for native speakers of Italian undergoing awake surgery – an object naming task and a finite verb production task. We administered the finite verb production task and other picture naming tasks to subjects with post-stroke aphasia, and established that a task that uses finite verbs shows a strong correlation with communicative abilities in daily life. Also, we introduced and compared our standardized finite verb task in the operating theater and compared it with an object naming task. Our tests are currently and successfully used in different surgery wards in Italy and overseas. This work can be extended to other neurological populations such as stroke, dementias, and epilepsy.
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Van, Geems Barbara Anne. "The development of a simple stereotactic device for neurosurgical applications." Thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/26285.
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Mogere, Edwin. "Impact of secondary insults on the outcome of paediatric traumatic brain injury : a retrospective cross sectional study at the Red Cross Children’s Hospital, Cape Town." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/13970.
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Includes bibliographical references.Secondary insults in severe traumatic brain injury (TBI) may worsen outcome; however, these are poorly characterized in children. For example, despite the known association between intracranial pressure (ICP) and poor outcome, there are few large paediatric series on the subject, definitions vary, functional outcome is often not assessed, and the best measures to assess ICP for statistical analysis are unknown. We aimed to document the frequency of secondary insults, and the association of various ICP measures, with outcome in a large cohort of paediatric patients with severe TBI. A retrospective analysis of 5-year prospectively collected data was examined for the frequency of hypoxia, hypotension, raised ICP, and low cerebral perfusion pressure (CPP). ICP parameters included initial ICP, mean ICP in the first 24 hours, mean ICP overall, peak ICP, mean ICP over 20 mmHg, and episodes of ICP over 20 mmHg. Hypotension was defined by age †and height †adjusted mean arterial pressure ranges, and hypoxia was defined as arterial partial pressure of oxygen (PaO2) less than 8kPa or pulse oximetry less than 90%. We examined for univariate and multivariate associations with mortality and the Extended Paediatric Glasgow Outcome Score.
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Collins, Donald Louis. "Volumetric rendering of medical data : applications to stereotactic neurosurgery planning." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59545.
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This thesis addresses the problem of registration, merging and viewing medical images from multiple modalities for stereotactic surgery planning. A technique is presented, using volumetric rendering of tomographic data, to create anatomical perspective projections that can be easily merged with vascular projections.The geometry of the digital subtraction angiogram (DSA) projection is reproduced by the rendering process to enable registration between the DSA radiograph and the volumetric projection. The viewing parameters are calculated from the location of fiducial markers in the image. Each angiogram is overlayed onto a translucent volumetric projection of computed tomography (CT) or magnetric resonance (MR) data, rendered to give a matched view.
Until recently, rendered medical volumes have been used qualitatively in the diagnostic and surgical planning process. Since the volumetric projections are matched to the DSA images, the complete set of stereotactic surgery planning tools can be used to identify points and measure distances in the rendered images.
A point spread function of the rendering process is derived to establish a theoretical limit on the accuracy of the technique and is verified by experimentation.
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Henri, Christopher J. "Application of stereoscopic digital subtraction angiography to stereotactic neurosurgery planning." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55692.
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Ovinis, Mark. "Computer vision techniques for a robot-assisted emergency neurosurgery system." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8502.
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This thesis presents the development of computer vision techniques for a robot-assisted emergency neurosurgery system that is being developed by the Mechatronics in Medicine group at Loughborough University, UK, and situates them within the context of the overall project. There are two main contributions in this thesis. The first is the development of a registration framework, to establish spatial correspondence between a preoperative plan of a patient (based on computed tomography images) and the patient. The registration is based on the rigid transformation of homologous anatomical soft tissue point landmarks of the head, the medial canthus and tragus, in CT and patient space. As a step towards automating the registration, a computational framework to localise these landmarks in CT space, with performance comparable to manual localisation, has been developed. The second contribution in this thesis is the development of computer vision techniques for a passive intraoperative supervisory system, based on visual cues from the operative site. Specifically, the feasibility of using computer vision to assess the outcome of a surgical intervention was investigated. The ability to mimic and embody part of a surgeon s visual sensory and decision-making capability is aimed at improving the robustness of the robotic system. Low-level image features to distinguish the two possible outcomes, complete and incomplete, were identified. Encouraging results were obtained for the surgical actions under consideration, which have been demonstrated by experiments on cadaveric pig heads. The results obtained are suggestive of the potential use of computer vision to assist surgical robotics in an operating theatre. The computational approaches developed, to provide greater autonomy to the robotic system, have the potential to improve current practice in robotic surgery. It is not inconceivable that the state of the art in surgical robotics can advance to a stage where it is able to emulate the ability and interpretation process of a surgeon.
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Mühle, Richard, Hannes Ernst, Stephan B. Sobottka, and Ute Morgenstern. "Workflow and hardware for intraoperative hyperspectral data acquisition in neurosurgery." Walter de Gruyter GmbH, 2020. https://tud.qucosa.de/id/qucosa%3A74394.
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To prevent further brain tumour growth, malignant tissue should be removed as completely as possible in neurosurgical operations. Therefore, differentiation between tumour and brain tissue as well as detecting functional areas is very important. Hyperspectral imaging (HSI) can be used to get spatial information about brain tissue types and characteristics in a quasi-continuous reflection spectrum. In this paper, workflow and some aspects of an adapted hardware system for intraoperative hyperspectral data acquisition in neurosurgery are discussed. By comparing an intraoperative with a laboratory setup, the influences of the surgical microscope are made visible through the differences in illumination and a pixel- and wavelength-specific signal-to-noise ratio (SNR) calculation. Due to the significant differences in shape and wavelength-dependent intensity of light sources, it can be shown which kind of illumination is most suitable for the setups. Spectra between 550 and 1,000 nm are characterized of at least 40 dB SNR in laboratory and 25 dB in intraoperative setup in an area of the image relevant for evaluation. A first validation of the intraoperative hyperspectral imaging hardware setup shows that all system parts and intraoperatively recorded data can be evaluated. Exemplarily, a classification map was generated that allows visualization of measured properties of raw data. The results reveal that it is possible and beneficial to use HSI for wavelength-related intraoperative data acquisition in neurosurgery. There are still technical facts to optimize for raw data detection prior to adapting image processing algorithms to specify tissue quality and function.:Abstract
Introduction
Materials and methods (Clinical workflow and setup for hyperspectral imaging process, Characteristics of the lighting, Characteristics of the hyperspectral imaging camera, Spectral data acquisition and raw data pre-processing in neurosurgery, Spectral data evaluation)
Results (Spectral characteristics of the lighting, SNR of the HSI camera, Data acquisition and raw data preprocessing during neurosurgical operation, Spectral data evaluation)
Discussion
Conclusions
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Hyam, Jonathan A. "Deep brain stimulation : manipulation of physiology and pathophysiology by neurosurgery." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589612.
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The capability of the brain to control the body has been recognised for millennia. This thesis evaluates the ability of neurosurgery, in the form of DBS, to manipulate the motor system, in which it is already established as a therapy, and the cardiovascular and respiratory systems, in which its application as a therapy would represent a major paradigm shift in medical practice. Patients with in-dwelling deep brain stimulators were enrolled in a series of experiments. Methodological techniques included the recording and analysis of cardiovascular and lung function indices, deep brain local field potentials, tremor severity scores and diffusion tensor tractograms. The results demonstrate that DBS at specific subcortical sites can ameliorate the abnormal response to autonomic challenges in Parkinson's disease and improve lung function by up to 15% with a coincident synchronisation of local field potential frequency. Further, the results demonstrate that probabilistic tractography in humans confirms the connections of the motor thalamus seen in animal tracer studies and that motor thalamus DBS for essential tremor is efficacious based on novel trial design and analysis methods. In conclusion, the thesis provides the first Level I evidence for the efficacy of DBS in essential tremor and suggests that probabilistic tractography can aid surgical targeting of the motor thalamus. It also finds that DBS reduces the cardiovascular dysfunction seen in Parkinson's disease and improves respiratory performance in humans with a coincident electrophysiological correlate in the subcortical brain. These findings have important implications for the future application of neurosurgery in diseases of not just the motor system but also the cardiovascular and respiratory systems.