Artículos de revistas: "Electroencephalographic (EEG)"

1

Al-Sulaiman, Abdulsalam. "Electroencephalographic (EEG) patterns in hydrocephalus". Electroencephalography and Clinical Neurophysiology 87, n.º 2 (agosto de 1993): S79. http://dx.doi.org/10.1016/0013-4694(93)91212-j.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Bruhn, Jörgen, Thomas W. Bouillon, Andreas Hoeft y Steven L. Shafer. "Artifact Robustness, Inter- and Intraindividual Baseline Stability, and Rational EEG Parameter Selection". Anesthesiology 96, n.º 1 (1 de enero de 2002): 54–59. http://dx.doi.org/10.1097/00000542-200201000-00015.

Texto completo

Resumen

Background Artifact robustness (i.e., size of deviation of an electroencephalographic parameter value from baseline caused by artifacts) and baseline stability (i.e., consistency of median baseline values) of electroencephalographic parameters profoundly influence electroencephalography-based pharmacodynamic parameter estimation and the usefulness of the processed electroencephalogram as measure of the arousal state of the central nervous system (depth of anesthesia). In this study, the authors compared the artifact robustness and the interindividual and intraindividual baseline stability of several univariate descriptors of the electroencephalogram (Shannon entropy, approximate entropy, spectral edge frequency 95, delta ratio, and canonical univariate parameter). Methods Electroencephalographic data of 16 healthy volunteers before and after administration of an intravenous bolus of propofol (2 mg/kg body weight) were analyzed. Each volunteer was studied twice. The baseline electroencephalogram was recorded for a median of 18 min before drug administration. For each electroencephalographic descriptor, the authors calculated the following: (1) baseline variability (= (median baseline - median effect) [i.e., signal]/SD baseline [i.e., noise]) without artifact rejection; (2) baseline variability with artifact rejection; and (3) baseline stability within and between individuals (= (median baseline - median effect) averaged over all volunteers/SD of all median baselines). Results Without artifact rejection, Shannon entropy and canonical univariate parameter displayed the highest signal-to-noise ratio. After artifact rejection, approximate entropy, Shannon entropy, and the canonical univariate parameter displayed the highest signal-to-noise ratio. Baseline stability within and between individuals was highest for approximate entropy. Conclusions With regard to robustness against artifacts, the electroencephalographic entropy parameters and the canonical univariate parameter were superior to spectral edge frequency 95 and delta ratio. Electroencephalographic approximate entropy displayed the best interindividual and intraindividual baseline stability.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Ivanov, A. A. "The structure of modern EEG recorder". Epilepsy and paroxysmal conditions 14, n.º 4 (18 de enero de 2023): 362–78. http://dx.doi.org/10.17749/2077-8333/epi.par.con.2022.138.

Texto completo

Resumen

The article is aimed at familiarizing medical specialists involved in registration and analysis of electroencephalographic (EEG) examinations with the basic principles of operation and the design of a modern EEG recorder. Understanding the technical fundamentals behind operation of EEG equipment should help medical personnel to correctly use all its capabilities and ultimately improve quality of medical care. The basic diagram of the electroencephalograph operation, the types and features of EEG electrodes, the opportunities and limitations of digitally processed bioelectric signals are discussed. A review on the main technical characteristics of EEG equipment and their influence on the quality of the recorded signal is presented.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Politi, Keren, Sara Kivity, Hadassa Goldberg-Stern, Ayelet Halevi y Avinoam Shuper. "Selective Mutism and Abnormal Electroencephalography (EEG) Tracings". Journal of Child Neurology 26, n.º 11 (18 de mayo de 2011): 1377–82. http://dx.doi.org/10.1177/0883073811406731.

Texto completo

Resumen

Epileptic discharges are not considered a part of the clinical picture of selective mutism, and electroencephalography is generally not recommended in its work-up. This report describes 6 children with selective mutism who were found to have a history of epilepsy and abnormal interictal or subclinical electroencephalography recordings. Two of them had benign epilepsy of childhood with centro-temporal spikes. The mutism was not related in time to the presence of active seizures. While seizures could be controlled in all children by medications, the mutism resolved only in 1. Although the discharges could be coincidental, they might represent a co-morbidity of selective mutism or even play a role in its pathogenesis. Selective mutism should be listed among the psychiatric disorders that may be associated with electroencephalographic abnormalities. It can probably be regarded as a symptom of a more complicated organic brain disorder.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

D'Souza, Delon, Gosala R. K. Sarma y Elizabeth V. T. "Teaching Electroencephalography: Persistent Altered Sensorium with Ominous Appearing Electroencephalographic Activity". International Journal of Epilepsy 05, n.º 02 (octubre de 2018): 110–11. http://dx.doi.org/10.1055/s-0038-1676560.

Texto completo

Resumen

AbstractA 51-year-old man presented with persistent altered sensorium following a seizure. His magnetic resonance imaging (MRI) showed features of focal encephalitis involving the left temporal, parietal, and occipital regions. His electroencephalogram (EEG) showed ongoing epileptiform discharges over the left hemisphere. This article discusses dilemmas in the diagnosis of nonconvulsive status epilepticus in such a case scenario.

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Stankevich, Lev A., Sabina S. Amanbaeva y Aleksandr V. Samochadin. "User Authentication by Electroencephalographic Signals when Blinkin". Computer tools in education, n.º 3 (30 de septiembre de 2019): 52–69. http://dx.doi.org/10.32603/2071-2340-2019-3-52-69.

Texto completo

Resumen

The article presents the results of a study in the field of applying electroencephalography (EEG) for human authentication. An algorithm for EEG authentication based on blinks has been developed and described. Authentication is carried out by one blink, which takes 2-5 seconds. The data is collected using a Muse electroencephalograph. Data preprocessing includes wavelet transform and blink detection. Geometric characteristics of the EEG signals are used as features. Recognition is conducted by the Random Forest classifier. According to the test results, the percentage of correct authentication was 95 %. There is the possibility of background authentication. The implemented system may be used to authenticate students at distant education.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Quesney, L. F. "Preoperative Electroencephalographic Investigation in Frontal Lobe Epilepsy: Electroencephalographic and Electrocorticographic Recordings". Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 18, S4 (noviembre de 1991): 559–63. http://dx.doi.org/10.1017/s0317167100032698.

Texto completo

Resumen

ABSTRACT:The first section of this article deals with specific anatomic and pathophysiologic factors which contribute to a poor EEG localization of the interictal epileptic abnormality and to the unreliable seizure onset localization commonly reported in patients with frontal lobe epilepsy. The localizing effectiveness of long term EEG monitoring was reviewed in four different groups of frontal lobe epileptic patients who underwent preoperative EEG investigation with extracranial and intracranial electrodes. The results of this study reveal a continuum distribution of interictal epileptic disturbances, ranging from focal abnormalities to lobar or multi-lobar epileptogenesis. A frontal lobe localization of the seizure generator based on ictal recordings obtained with extracranial electrodes is rather poor and much more reliable results can be obtained by depth-electroencephalography.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

McFarland, Dennis J., William A. Sarnacki y Jonathan R. Wolpaw. "Electroencephalographic (EEG) control of three-dimensional movement". Journal of Neural Engineering 7, n.º 3 (11 de mayo de 2010): 036007. http://dx.doi.org/10.1088/1741-2560/7/3/036007.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Yeh, Ta-Chuan, Cathy Chia-Yu Huang, Yong-An Chung, Jooyeon Jamie Im, Yen-Yue Lin, Chin-Chao Ma, Nian-Sheng Tzeng, Chuan-Chia Chang y Hsin-An Chang. "High-Frequency Transcranial Random Noise Stimulation over the Left Prefrontal Cortex Increases Resting-State EEG Frontal Alpha Asymmetry in Patients with Schizophrenia". Journal of Personalized Medicine 12, n.º 10 (7 de octubre de 2022): 1667. http://dx.doi.org/10.3390/jpm12101667.

Texto completo

Resumen

Reduced left-lateralized electroencephalographic (EEG) frontal alpha asymmetry (FAA), a biomarker for the imbalance of interhemispheric frontal activity and motivational disturbances, represents a neuropathological attribute of negative symptoms of schizophrenia. Unidirectional high-frequency transcranial random noise stimulation (hf-tRNS) can increase the excitability of the cortex beneath the stimulating electrode. Yet, it is unclear if hf-tRNS can modulate electroencephalographic FAA in patients with schizophrenia. We performed a randomized, double-blind, sham-controlled clinical trial to contrast hf-tRNS and sham stimulation for treating negative symptoms in 35 schizophrenia patients. We used electroencephalography to investigate if 10 sessions of hf-tRNS delivered twice-a-day for five consecutive weekdays would modulate electroencephalographic FAA in schizophrenia. EEG data were collected and FAA was expressed as the differences between common-log-transformed absolute power values of frontal right and left hemisphere electrodes in the alpha frequency range (8–12.5 Hz). We found that hf-tRNS significantly increased FAA during the first session of stimulation (p = 0.009) and at the 1-week follow-up (p = 0.004) relative to sham stimulation. However, FAA failed to predict and surrogate the improvement in the severity of negative symptoms with hf-tRNS intervention. Together, our findings suggest that modulating electroencephalographic frontal alpha asymmetry by using unidirectional hf-tRNS may play a key role in reducing negative symptoms in patients with schizophrenia.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Sheikh, Hesham, Dennis J. McFarland, William A. Sarnacki y Jonathan R. Wolpaw. "Electroencephalographic(EEG)-based communication: EEG control versus system performance in humans". Neuroscience Letters 345, n.º 2 (julio de 2003): 89–92. http://dx.doi.org/10.1016/s0304-3940(03)00470-1.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Jan, Mohammed M., Mark Sadler y Susan R. Rahey. "Electroencephalographic Features of Temporal Lobe Epilepsy". Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 37, n.º 4 (julio de 2010): 439–48. http://dx.doi.org/10.1017/s0317167100010441.

Texto completo

Resumen

Electroencephalography (EEG) is an important tool for diagnosing, lateralizing and localizing temporal lobe seizures. In this paper, we review the EEG characteristics of temporal lobe epilepsy (TLE). Several “non-standard” electrodes may be needed to further evaluate the EEG localization, Ictal EEG recording is a major component of preoperative protocols for surgical consideration. Various ictal rhythms have been described including background attenuation, start-stop-start phenomenon, irregular 2-5 Hz lateralized activity, and 5-10 Hz sinusoidal waves or repetitive epileptiform discharges. The postictal EEG can also provide valuable lateralizing information. Postictal delta can be lateralized in 60% of patients with TLE and is concordant with the side of seizure onset in most patients. When patients are being considered for resective surgery, invasive EEG recordings may be needed. Accurate localization of the seizure onset in these patients is required for successful surgical management.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Gevins, Alan, Michael E. Smith, Linda K. McEvoy, Harrison Leong y Jian Le. "Electroencephalographic imaging of higher brain function". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, n.º 1387 (29 de julio de 1999): 1125–34. http://dx.doi.org/10.1098/rstb.1999.0468.

Texto completo

Resumen

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. Electroencephalography (EEG) provides temporal resolution in the millisecond range. However, traditional EEG technology and practice provide insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. Recent advances help to overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical images, and by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp. In addition, statistical measurements of sub-second interdependences between EEG time-series recorded from different locations can help to generate hypotheses about the instantaneous functional networks that form between different cortical regions during perception, thought and action. Example applications are presented from studies of language, attention and working memory. Along with its unique ability to monitor brain function as people perform everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities.

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Roceanu, Adina, Ioana Mindruta, Amalia Ene, Elena Copaciu, Ovidiu Lucian Bajenaru, Ovidiu Alexandru Bajenaru y Cristina Tiu. "Electroencephalographic evaluation in patients with impaired consciousness". Romanian Journal of Neurology 12, n.º 4 (31 de diciembre de 2013): 169–74. http://dx.doi.org/10.37897/rjn.2013.4.1.

Texto completo

Resumen

The electroencephalographic examination (EEG) records spontaneous electrical activity generated in the cerebral cortex. The EEG is abnormal in almost all conditions associated with impairment of the level of consciousness. When consciousness is impaired the EEG becomes slowed (episodic or continuous), unresponsive to afferent stimuli, amplitude diminishes until eventually becomes flat. Coma may have various causes. EEG is a diagnostic and prognostic tool in acute anoxic coma. EEG is the only diagnostic tool for detecting a non-convulsive epileptic status.

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Aleksandrov, Mikhail V., Tatiana V. Aleksandrova y Ekaterina S. Povaliukhina. "Electroencephalographic monitoring in the intensive care unit". HERALD of North-Western State Medical University named after I.I. Mechnikov 10, n.º 3 (19 de noviembre de 2018): 81–90. http://dx.doi.org/10.17816/mechnikov201810381-90.

Texto completo

Resumen

EEG performance in the intensive care unit in critically ill patients can be provisionally allocated to a special type of research — EEG of critical states. The article deals with the methodological features of EEG performance in intensive care, as well as general patterns of EEG changes in patients in coma. The analysis of the patterns of the EEG in intensive care unit is described. Parameters of reactivity of the central nervous system are given. An algorithm for describing epileptiform changes is presented. The criteria for the diagnosis of nonconvulsive status epilepticus in patients unconscious are discussed, as well as a prognosis of the outcome of a long unconscious state in the presence of epileptiform changes in the EEG. Data on the parameters of periodic patterns are collected, their description and diagnostic criteria are given. The role and possibilities of EEG in the diagnosis of brain death are considered.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Young, G. B., R. S. McLachlan, J. H. Kreeft y J. D. Demelo. "An Electroencephalographic Classification for Coma". Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 24, n.º 04 (noviembre de 1997): 320–25. http://dx.doi.org/10.1017/s0317167100032996.

Texto completo

Resumen

ABSTRACT:Background:The assessment of thalamocortical function in comatose patients in the intensive care unit (ICU) can be difficult to determine. Since the electroencephalogram (EEG) affords such assessment, we have developed an EEG classification for comatose patients in our general ICU.Methods:One hundred EEGs were classified in a blinded fashion by two EEGers, using our method and that of Synek. Interobserver agreement was assessed using kappa score determination.Results:Kappa scores were 0.90 for our system and 0.75 for the Synek system. (The Kappa score represents the inter-rater agreement that is beyond chance; 0.90 is almost perfect agreement, while 0.75 is substantial agreement).Conclusion:Our system for classifying EEGs in comatose patients has a higher interobserver reliability than one that was previously published. This EEG classification scheme should be useful in clinical electrophysiological research involving ICU patients, allowing for internal consistency and comparisons among centres.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Mattia, A. "Electroencephalographic (EEG), EEG power spectra, and behavioral correlates in rats given phencyclidine". Neuropharmacology 25, n.º 7 (julio de 1986): 763–69. http://dx.doi.org/10.1016/0028-3908(86)90093-6.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Stark, R. I., J. Haiken, D. Nordli y M. M. Myers. "Characterization of electroencephalographic state in fetal baboons". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 261, n.º 2 (1 de agosto de 1991): R496—R500. http://dx.doi.org/10.1152/ajpregu.1991.261.2.r496.

Texto completo

Resumen

Long-term recordings of the electroencephalograms (EEGs) from the non-human fetal primate have been visually scored for state. Data were obtained from three fetuses using recently developed techniques for chronic instrumentation of the pregnant baboon. Seven days or more after surgery, nine chart records of 4-5 h in duration were analyzed. These records were made during an interval in gestation from 143 to 153 days (term = 175 to 185 days). Criteria for differentiation of EEG state were based on the presence (state 1) or absence (state 2) of trace alternant, which is the predominant characteristic of EEG activity during quiet sleep in human preterm and term infants. Two patterns of EEG activity were readily distinguished at both standard (30 mm/s) and compressed (30 mm/min) EEG chart speeds. On a minute-by-minute basis, there was an overall concurrence of 82.9% for EEG state when scored from compressed and standard EEG records. From the compressed records, state 1 was present on average 38.3% of the time, with a mean epoch duration of 15.1 min, while epochs of state 2 averaged 25.9 min. We conclude that at least two EEG states are present at this gestation in the fetal baboon. These two states can be reliably defined visually by scoring methods directly comparable to those used for EEG recognition of sleep states in the human newborn infant. To validate the conclusion that these fetal state assignments based on patterns of EEG activity correspond to sleep states, it will be necessary to determine if the oscillations of other physiological parameters are coherent with these patterns.

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Lee, MD, Ki Hwa. "Beyond the index of processed electroencephalography: a narrative review". Anaesthesia, Pain & Intensive Care 27, n.º 1 (31 de enero de 2023): 112–18. http://dx.doi.org/10.35975/apic.v27i1.2128.

Texto completo

Resumen

There is a growing interest in monitoring the processed electroencephalography (p-EEG) as a measure of the delivery of anesthetic agent and the depth of the general anesthesia (GA). Each p-EEG monitor constructs an index that is suitable for GA. Although these monitors have become widely used, but it remains controversial whether they can become the gold standard for anesthesia monitoring like pulse oximeter and electrocardiogram. Whether p-EEG-guided anesthesia can affect perioperative outcomes remains unclear. This narrative review describes the relationship between p-EEG monitoring and perioperative outcome such as postoperative neurocognitive function, intraoperative awareness and mortality. Also, this article describes how and what to look beyond the index of processed electroencephalographic monitors. Abbreviations: GA: General anesthesia; EEG: Electroencephalogram; BIS: Bispectral index; POD: Postoperative delirium; CODA: Cognitive Dysfunction after Anaesthesia; POCD: Postoperative cognitive dysfunction; PACU: Post-anesthetic care unit; POQI-6: Perioperative Quality Initiative-6 Consensus Key words: Anesthesia; Delirium; Electroencephalography; Intraoperative awareness; Mortality Citation: Lee KH. Beyond the index of processed electroencephalography: a narrative review. Anaesth. pain intensive care 2022;27(1):112−118; DOI: 10.35975/apic.v27i1.2128 Received: April 07, 2022; Reviewed: August 16, 2022; Accepted: October 20, 2022

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Igor, Prpic, Radic Nisevic Jelena, Begic Jelena, Kapovic Radojka y Kolic Ivana. "Electroencephalographic (EEG) RECORDING during sleep induced by melatonin". European Journal of Paediatric Neurology 21 (junio de 2017): e98. http://dx.doi.org/10.1016/j.ejpn.2017.04.736.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

WATANABE, Shigenori, Hisashi OHTA, Kimihiro YAMASHITA, Masuo OHNO, Yoshihiro TANI, Yoshiaki FURUYA y Showa UEKI. "Electroencephalographic(EEG) effect of quinupramine in the rabbit." Folia Pharmacologica Japonica 89, n.º 6 (1987): 339–54. http://dx.doi.org/10.1254/fpj.89.339.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Toderean, Roxana, Mihai Dimian y Claudiu Cobuz. "EEG Changes Related to Gut Dysbiosis in Diabetes—Review". Applied Sciences 11, n.º 24 (14 de diciembre de 2021): 11871. http://dx.doi.org/10.3390/app112411871.

Texto completo

Resumen

Humans are facing a devastating epidemic of metabolic syndrome that is linked to the worldwide dramatic increase in obesity and diabetes. Significant evidence suggests that the intestinal microbiota plays a major role in the pathogenesis of metabolic diseases. Due to the gut–brain axis link, dysbiosis in the gut microbiota have been demonstrated in both metabolic and neurological disease. Increasing evidence suggests that the gut microbiota is very important in maintaining health and changes in its composition may contribute to psychiatric and neurodegenerative disorders. It is also in research that changes in microbiota composition profile due to diabetes are modulated by the vagus nerve. Therefore, it is plausible that disruptions in the gut microbiota may be captured through electroencephalography signaling. Several studies which used standard methods of signal processing have highlighted some changes in electroencephalographic rhythms on patients with diabetes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Carvalho, Marcele Regine de, Bruna Brandao Velasques, Mauricio Cagy, Juliana Bittencourt Marques, Silmar Teixeira, Antonio Egidio Nardi, Roberto Piedade y Pedro Ribeiro. "Electroencephalographic findings in panic disorder". Trends in Psychiatry and Psychotherapy 35, n.º 4 (diciembre de 2013): 238–51. http://dx.doi.org/10.1590/2237-6089-2013-0012.

Texto completo

Resumen

Some studies have reported the importance of electroencephalography (EEG) as a method for investigating abnormal parameters in psychiatric disorders. Different findings in time and frequency domain analysis with regard to central nervous system arousal during acute panic states have already been obtained. This study aimed to systematically review the EEG findings in panic disorder (PD), discuss them having a currently accepted neuroanatomical hypothesis for this pathology as a basis, and identify limitations in the selected studies. Literature search was conducted in the databases PubMed and ISI Web of Knowledge, using the keywords electroencephalography and panic disorder; 16 articles were selected. Despite the inconsistency of EEG findings in PD, the major conclusions about the absolute power of alpha and beta bands point to a decreased alpha power, while beta power tends to increase. Different asymmetry patterns were found between studies. Coherence studies pointed to a lower degree of inter-hemispheric functional connectivity at the frontal region and intra-hemispheric at the bilateral temporal region. Studies on possible related events showed changes in memory processing in PD patients when exposed to aversive stimuli. It was noticed that most findings reflect the current neurobiological hypothesis of PD, where inhibitory deficits of the prefrontal cortex related to the modulation of amygdala activity, and the subsequent activation of subcortical regions, may be responsible to trigger anxiety responses. We approached some important issues that need to be considered in further researches, especially the use of different methods for analyzing EEG signals. Keywords: Electroencephalography, panic disorder, neurobiology, brain mapping.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Röpcke, Heiko, Benno Rehberg, Michael Koenen-Bergmann, Thomas Bouillon, Jörgen Bruhn y Andreas Hoeft. "Surgical Stimulation Shifts EEG Concentration–Response Relationship of Desflurane". Anesthesiology 94, n.º 3 (1 de marzo de 2001): 390–99. http://dx.doi.org/10.1097/00000542-200103000-00006.

Texto completo

Resumen

Background Anesthesiologists routinely increase the delivered anesthetic concentration before surgical stimulation in anticipation of increased anesthetic requirement to achieve certain goals (e.g., amnesia, unconsciousness, and immobility). Electroencephalographic monitoring is one method of determining indirectly anesthetic effect on the brain. The present study investigated the effect of surgical stimuli on the concentration-response relation of desflurane-induced electroencephalographic changes. Methods The electroencephalographic activity was recorded from 24 female patients who received only desflurane after a single induction dose of propofol. Twelve patients served as a control group before surgical stimulation. The other 12 patients, all undergoing lower abdominal surgery, were investigated between opening and closure of the peritoneum. Desflurane vaporizer settings were randomly increased and decreased between 0.5 and 1.6 minimum alveolar concentration as long as anesthesia was considered adequate. Spectral edge frequency 95, median power frequency, and Bispectral Index were calculated. Desflurane effect-site concentrations and the concentration-effect curves for spectral edge frequency 95, median power frequency, and Bispectral Index were determined by simultaneous pharmacokinetic and pharmacodynamic modeling. Results Surgical stimulation shifted the desflurane concentration-electroencephalographic effect curves for spectral edge frequency 95, median power frequency, and Bispectral Index toward higher desflurane concentrations. In the unstimulated group, 2.2 +/- 0.74 vol% desflurane were necessary to achieve a Bispectral Index of 50, whereas during surgery, 6.8 +/- 0.98 vol% (mean +/- SE) were required. Conclusions During surgery, higher concentrations of the volatile anesthetic are required to achieve a desired level of cortical electrical activity and, presumably, anesthesia.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Weisdorf, Sigge, Sirin W. Gangstad, Jonas Duun-Henriksen, Karina S. S. Mosholt y Troels W. Kjær. "High similarity between EEG from subcutaneous and proximate scalp electrodes in patients with temporal lobe epilepsy". Journal of Neurophysiology 120, n.º 3 (1 de septiembre de 2018): 1451–60. http://dx.doi.org/10.1152/jn.00320.2018.

Texto completo

Resumen

Subcutaneous recording using electroencephalography (EEG) has the potential to enable ultra-long-term epilepsy monitoring in real-life conditions because it allows the patient increased mobility and discreteness. This study is the first to compare physiological and epileptiform EEG signals from subcutaneous and scalp EEG recordings in epilepsy patients. Four patients with probable or definite temporal lobe epilepsy were monitored with simultaneous scalp and subcutaneous EEG recordings. EEG recordings were compared by correlation and time-frequency analysis across an array of clinically relevant waveforms and patterns. We found high similarity between the subcutaneous EEG channels and nearby temporal scalp channels for most investigated electroencephalographic events. In particular, the temporal dynamics of one typical temporal lobe seizure in one patient were similar in scalp and subcutaneous recordings in regard to frequency distribution and morphology. Signal similarity is strongly related to the distance between the subcutaneous and scalp electrodes. On the basis of these limited data, we conclude that subcutaneous EEG recordings are very similar to scalp recordings in both time and time-frequency domains, if the distance between them is small. As many electroencephalographic events are local/regional, the positioning of the subcutaneous electrodes should be considered carefully to reflect the relevant clinical question. The impact of implantation depth of the subcutaneous electrode on recording quality should be investigated further. NEW & NOTEWORTHY This study is the first publication comparing the detection of clinically relevant, pathological EEG features from a subcutaneous recording system designed for out-patient ultra-long-term use to gold standard scalp EEG recordings. Our study shows that subcutaneous channels are very similar to comparable scalp channels, but also point out some issues yet to be resolved.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Sá, Catarina, Paulo Veloso Gomes, António Marques y António Correia. "The Use of Portable EEG Devices in Development of Immersive Virtual Reality Environments for Converting Emotional States into Specific Commands". Proceedings 54, n.º 1 (25 de agosto de 2020): 43. http://dx.doi.org/10.3390/proceedings2020054043.

Texto completo

Resumen

The application of electroencephalography electrodes in Virtual Reality (VR) glasses allows users to relate cognitive, emotional, and social functions with the exposure to certain stimuli. The development of non-invasive portable devices, coupled with VR, allows for the collection of electroencephalographic data. One of the devices that embraced this new trend is Looxid LinkTM, a system that adds electroencephalography to HTC VIVETM, VIVE ProTM, VIVE Pro EyeTM, or Oculus Rift STM glasses to create interactive environments using brain signals. This work analyzes the possibility of using the Looxid LinkTM device to perceive, evaluate and monitor the emotions of users exposed to VR.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Galvan, Pedro, Ronald Rivas, Carlos Arbo, Marta Cabrera, Silvia Abente, Juan Portillo, Julio Mazzoleni y Enrique Hilario. "OP179 Nationwide Electroencephalographic Screening Using Telemedicine Apps". International Journal of Technology Assessment in Health Care 36, S1 (diciembre de 2020): 2–3. http://dx.doi.org/10.1017/s0266462320000938.

Texto completo

Resumen

IntroductionDisruptive telemedicine tools can help overcome the lack of specialized care and electroencephalographic (EEG) support for diagnosing and treating nervous system disorders such as epilepsy in remote communities. However, evidence on how such cloud-based platforms could enhance data-driven health care is limited. The utility of telemedicine-based apps to achieve EEG screening of communities in rural areas of Paraguay was investigated.MethodsThis descriptive study was carried out by the Telemedicine Unit of the Ministry of Public Health in collaboration with the Department of Biomedical Engineering and Imaging of the Health Science Research Institute in Paraguay and the Basque Country University in Spain to evaluate the utility of telediagnostic apps for EEG screening. For this purpose, the results obtained by tele-EEG apps implemented in nineteen public community hospitals were analyzed to determine the utility of the apps as epidemiological surveillance tools.ResultsAmong the 10,791 remote EEG studies performed, the most common reasons for the test included epileptic seizure (44%), headache (22%), seizure disorder (8%), follow up (6%), attention deficits in children (5%), cognitive impairment (4%), cranioencephalic trauma (3%), brain death (1%), history of seizure (0.9%), abnormal movements (0.7%), and behavioral disorders (0.5%).ConclusionsThe results showed that telemedicine apps can significantly enhance nationwide EEG screening by freeing up professional time and increasing productivity, improving access and equity, and reducing costs. However, before their systematic implementation a contextualization of the apps using the regional epidemiological profile must be performed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Aguilar-Fabré, Liane y Francisco Rodríguez-Valdés. "Patrones electroencefalográficos periódicos: un hallazgo controversial e infrecuente". Revista Mexicana de Neurociencia 19, n.º 4 (1 de julio de 2018): 71–82. http://dx.doi.org/10.31190/rmn.2018.19.4.71.82.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Koponen, Hannu. "Electroencephalographic Indices for Diagnosis of Delirium". International Psychogeriatrics 3, n.º 2 (diciembre de 1991): 249–51. http://dx.doi.org/10.1017/s1041610291000704.

Texto completo

Resumen

The central nervous system electrical potentials recorded by the EEG are sensitive to alterations in the levels of consciousness and attention (Mesulam, 1986). Thus it is understandable that previous studies on delirious patients using routine EEGs have shown an increase of slow-wave activity and slowing and disruption of the normal alpha rhythm (Romano & Engel, 1944). At present, the electrocephalogram is widely accepted as a valuable ancillary laboratory procedure for diagnosis and serial evaluation of delirium, as EEG changes often accompany delirium.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Chowdhury, Ahmed Hossian, Rajib Nayan Chowdhury, Sharif Uddin Khan, Swapon Kumar Ghose, Amit Wazib, Iftikher Alam, ATM Hasibul Hasan, Kanol Shaha, Badrul Haque y Mansur Habib. "Electroencephalographic (EEG) correlation of clinical Seizure among Bangladeshi Patients". Community Based Medical Journal 3, n.º 2 (4 de agosto de 2014): 3–8. http://dx.doi.org/10.3329/cbmj.v3i2.53397.

Texto completo

Resumen

To detect the changes in electro encephalogram (EEG) and correlate the findings with clinical seizure events among epilepsy patients. This retrospective chart review was carried out in the electrophysiology laboratory of Dhaka Medical College Hospital from January 2011 to December 2013, which included 1154 patients. EEG was obtained through scalp electrodes following international 10/20 system. Information regarding patients was collected from the laboratory register with the help of a checklist. The EEG findings and clinical seizure events were then compared. Among the 1154 patients, age varied from birth to 75 years. The mean age at presentation was 17±11.4 years and most of the patients were less than 10 years old (44.4%). The male (59.2%) female ratio was 3:2 in our study. Clinically diagnosed seizure was present in 970 patients (84.1%), among which Generalized tonic clonic seizure (GTCS) was the most common clinical type of seizure, followed by secondary generalized seizure in 19.4% (n=224) and focal seizure in 2% (n=30) patients and 6.8% (n=79) patients had pseudoseizure. Among the abnormal EEG (59%), generalized epileptiform discharge was found in 29%, whereas focal and secondary generalized discharge was found in 30%. The most common site of origin of epileptiform discharge was temporal lobe (28.3%). There was a negative correlation between EEG and history of seizure events (pearson correlation significance 0.33). Our study brings out the fact that EEG has a negative correlation with clinical seizure events. CBMJ 2014 July: Vol. 03 No. 02 P: 03-08

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Gunawan, Prastiya Indra y Darto Saharso. "Seizure increases electroencephalographic abnormalities in children with tuberculous meningitis". Universa Medicina 34, n.º 3 (27 de abril de 2016): 161. http://dx.doi.org/10.18051/univmed.2015.v34.161-167.

Texto completo

Resumen

Background Tuberculous meningitis (TBM) is a severe intracranial infection with fatal outcomes, permanent disabilities, and electroencephalographic (EEG) abnormalities. Seizures may occur in TBM. The EEG findings in TBM vary according to the site of the inflammatory process. There are few studies describing the EEG patterns and clinical manifestations of TBM. The objective of this study was to investigate the correlation between clinical findings and EEG patterns in children with TBM. Methods A study of cross-sectional design using medical records was conducted on 12 children with TBM, with their EEG patterns classified as abnormal and normal. Clinical manifestations such as seizures, altered consciousness, headache or fever were collected. A positive cerebrospinal fluids Mycobacterium tuberculosis culture was considered to indicate definitive TBM. Abnormal EEG descriptions were classified into abnormal I, II or III. Correlation between EEG pattern and clinical manifestation were analyzed with Fisher’s exact test. Results The study found cases of 12 children with TBM, the majority presenting with seizures, decreased consciousness and fever. Abnormal EEGs were found in 75% of children and 77% of them showed epileptogenic activities. The EEG results mostly described epileptogenic potentials in the frontotemporal region. There was a significant correlation between EEG abnormality and seizures in children with TBM (p<0.05). Conclusions The EEG pattern in children with TBM varies, and EEG abnormalities were more frequently localized in the frontotemporal region. Seizures were associated with EEG abnormalities in children with TBM. EEG abnormalities occurring simultaneously with seizures may predict the occurrence of seizures.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Tempelhoff, Rene, Paul A. Modica, Keith M. Rich y Robert L. Grubb. "Use of computerized electroencephalographic monitoring during aneurysm surgery". Journal of Neurosurgery 71, n.º 1 (julio de 1989): 24–31. http://dx.doi.org/10.3171/jns.1989.71.1.0024.

Texto completo

Resumen

✓ The clinical usefulness of intraoperative electroencephalographic (EEG) monitoring of cerebral perfusion during aneurysm surgery has received little attention, primarily due to problems with electrode placement over the operative site, which is the area of maximal risk. In this report, 27 patients undergoing surgery for anterior circulation aneurysms were monitored intraoperatively with a two-channel computerized EEG complex using a bilateral frontal-occipital montage. In 16 patients, a normal EEG pattern was observed throughout surgery; all 16 awoke neurologically intact and their postoperative angiograms did not reveal cerebral vasospasm. In the other 11 patients, one of two patterns of persistent EEG abnormalities was identified. 1) In six of these patients a marked attenuation of EEG activity was observed ipsilaterally which coincided with various intraoperative events including brain retraction, hypotension, and aneurysm dissection/clipping. Five of these six patients awoke with new neurological deficits which persisted beyond 12 hours in two, both of whom had angiographically proven vasospasm 24 hours after surgery. 2) In the remaining five patients, a distinct abnormal EEG pattern consisting of marked hyperactivity in the delta, theta, and alpha frequency ranges was observed ipsilaterally. Four of these five patients had a poor neurological outcome and vasospasm on their angiogram 24 hours after surgery. Thus, EEG monitoring which spans the operative area during aneurysm surgery is practicable and appears to be of value in the detection of compromised cerebral perfusion during aneurysm surgery. The possible significance of the two abnormal EEG patterns identified in this report is discussed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Majoros, Tamás, Balázs Ujvári y Stefan Oniga. "EEG data processing with neural network". Carpathian Journal of Electronic and Computer Engineering 12, n.º 2 (1 de diciembre de 2019): 33–36. http://dx.doi.org/10.2478/cjece-2019-0014.

Texto completo

Resumen

Abstract Machine-learning techniques allow to extract information from electroencephalographic (EEG) recordings of brain activity. By processing the measurement results of a publicly available EEG dataset, we were able to obtain information that could be used to train a feedforward neural network to classify two types of volunteer activities with high efficiency.

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Zhavoronkova, Ludmila A., Nina B. Kholodova, Alexey P. Belostocky y Mikhail A. Koulikov. "Reduced Electroencephalographic Coherence Asymmetry in the Chernobyl Accident Survivors". Spanish Journal of Psychology 11, n.º 2 (noviembre de 2008): 363–73. http://dx.doi.org/10.1017/s113874160000439x.

Texto completo

Resumen

An electroencephalograph (EEG) study was carried out from 1990 to 2006, using power spectra, averaged coherence, and integral EEG coherence asymmetry coefficients to compare 189 clean-up workers of the Chernobyl accident with 63 age-matched healthy controls. Most of the Chernobyl workers showed three abnormal EEG patterns, as indicated by EEG power mapping. The higher power, most prominent in slow alpha and theta bands, or in fast alpha frequencies, were observed in persons 3-5 years after the clean-up works (the early stage). The lower EEG power in alpha band was found in Chernobyl workers 10 or more years after the accident (the late stage). EEG coherence analysis revealed the existence of two stages in EEG alterations following the Chernobyl clean-up. In the early stage, an increase of EEG coherence in the central brain areas was observed, whereas at the later stage, a decrease of EEG coherence, most prominent in the frontal brain areas, and reduced brain asymmetry prevailed. These results allow us to propose that the described EEG signs may be a reflection of radiation-induced brain dysfunction at the late period after the Chernobyl clean-up and were similar to the EEG markers of brain ageing. The results, in comparison to data of the literature, provide additional support to the premature brain ageing hypothesis in Chernobyl survivors as a result of the radiation brain damage after-effect.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Ghimire, Nisha, Bishnu Hari Paudel, Rita Khadka, Parash Nath Singh y Asim Das. "Electroencephalographic changes during selective attention". Asian Journal of Medical Sciences 6, n.º 2 (21 de septiembre de 2014): 51–56. http://dx.doi.org/10.3126/ajms.v6i2.11122.

Texto completo

Resumen

Background: Though many studies are conducted during attention process, it is still not clear how brain deals with attention. So we conducted a study to find out the electroencephalographic changes during selective attention.Methods: Thirty healthy right handed male students aged 23.1±2.8 yrs were asked to read congruent (red printed in red ink) and incongruent (red printed in blue ink) words printed in cards. EEG was recorded for ninety seconds during baseline (eye open) and reading of both cards. EEG epoch was analyzed by fast fourier transformation. Friedman test was used to compare EEG power spectra among baseline, congruent and incongruent reading followed by Wilcoxon’s Sign Rank Test. Data were expressed as median with inter-quartile range.Results: Compared to congruent test during incongruent test there was selective increment of theta power at Fz [36.04 (28.30-46.19) vs. 47.89 (31.65-48.1)], Cz[36.13 (27.20-46.41) vs. 45.66 (37.15-49.4)] and C4 [25.11 (19.14-30.06) vs. 30.16 (21.43-33.8)] sites but it decreased at F7 [17.88 (14.49-20.93) vs. 11.31(8.96-15.975)] and F8 [19.23 (13.61-25.79) vs. 13.95 (10.40-16.67) sites. Also during incongruent card reading, alpha1 power significantly decreased in F8 [3.39(2.63-4.63) to 2.75 (1.93-4.7)] and alpha 2 power significantly decreased in P3 6.84 [(4.88-10.46) to 5.74 (4.78-19.95)] sites.Conclusion: During selective attention, theta gets synchronized at fronto-central regions and alpha2 desynchronized at parietal regions. The theta and alpha1 at inferior frontal regions were also desynchronized in selective attention. DOI: http://dx.doi.org/10.3126/ajms.v6i2.11122Asian Journal of Medical Sciences Vol.6(2) 2015 52-57

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

McCreadie, R. G., K. Phillips, A. D. T. Robinson, G. Gilhooly y W. Crombie. "Is Electroencephalographic Monitoring of Electroconvulsive Therapy Clinically Useful?" British Journal of Psychiatry 154, n.º 2 (febrero de 1989): 229–31. http://dx.doi.org/10.1192/bjp.154.2.229.

Texto completo

Resumen

Electroencephalographic (EEG) monitoring was carried out in 169 bilateral and 114 unilateral applications of electroconvulsive therapy (ECT), given to 51 patients in an everyday setting within the National Health Service by junior medical staff. In 2.5% of bilateral and 8% of unilateral applications there was disagreement between clinical and EEG assessment as to whether a fit had occurred. When an EEG fit was said to have occurred only if it lasted longer than 25 seconds, then disagreement rose to 7% in bilateral and 28% in unilateral applications; disagreement was higher with unilateral applications, as they produced more short fits than bilateral applications. If future work shows duration of seizure is clearly associated with clinical efficacy, it is suggested the case for routine EEG monitoring is greatly strengthened.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Zhang, Jie, Yunxu Shi, Chienkai Wang, Chunmei Cao, Changshui Zhang, Linhong Ji, Jia Cheng y Fangfang Wu. "Preshooting Electroencephalographic Activity of Professional Shooters in a Competitive State". Computational Intelligence and Neuroscience 2021 (31 de enero de 2021): 1–9. http://dx.doi.org/10.1155/2021/6639865.

Texto completo

Resumen

This study investigated the influence of competitive state on cerebral cortex activity of professional shooters with 10 m air rifle before shooting. Generally, professional athletes have higher neural efficiency compared with ordinary people. We recruited 11 national shooters to complete 60 shots under both noncompetitive and competitive shooting conditions, and simultaneously collected their electroencephalogram (EEG) and electrocardiogram (ECG) information. Theta, alpha, and beta power were computed in the last three seconds preceding each shot from average-reference 29-channel EEG, while EEG characteristics under two conditions were analyzed. The results showed a significant linear correlation between shooting accuracy and EEG power of anterior frontal, central, temporal, and occipital regions in beta and theta bands. In addition, the theta power in occipital regions, alpha power in frontal-central and left occipital regions, and beta power in frontal and mid-occipital regions were higher than those in noncompetitive state. However, heart rate (HR) and shooting accuracy did not change significantly under the two conditions. These findings reveal the changes of cortical activity underlying competition shooting as well as providing further understanding of the neural mechanisms of the shooting process and lay a foundation for the subsequent neuromodulation research.

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Gustafsson, H. C., P. G. Grieve, E. A. Werner, P. Desai y C. Monk. "Newborn electroencephalographic correlates of maternal prenatal depressive symptoms". Journal of Developmental Origins of Health and Disease 9, n.º 4 (6 de marzo de 2018): 381–85. http://dx.doi.org/10.1017/s2040174418000089.

Texto completo

Resumen

AbstractMaternal perinatal depression exerts pervasive effects on the developing brain, as evidenced by electroencephalographic (EEG) patterns that differ between children of women who do and do not meet DSM or ICD diagnostic criteria. However, little research has examined if the same EEG pattern of right-frontal alpha asymmetry exists in newborns and thus originates in utero independent of postnatal influences, and if depressive symptoms are associated with this neural signature. Utilizing 125-lead EEG (n=18), this study considered clinician-rated maternal prenatal depressive symptoms in relation to newborn EEG. Maternal depressive symptomatology was associated with greater relative right-frontal alpha asymmetry during quiet sleep. These results suggest that even subclinical levels of maternal depression may influence infant brain development, and further support the role of the prenatal environment in shaping children’s future neurobehavioral trajectories.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Binelli, Simona, Francesca Ragona, Laura Canafoglia, Elena Freri, Veronica Saletti, Marina Casazza, Isabella Gilioli et al. "Electroencephalographic (EEG) Photoparoxysmal Responses Under 5 Years of Age". Journal of Child Neurology 30, n.º 13 (5 de mayo de 2015): 1824–30. http://dx.doi.org/10.1177/0883073815583687.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Yoshimura, Kohji y Masahito Horiuchi. "Electroencephalographic (EEG) study on NMDA receptor antagonists in dogs". Japanese Journal of Pharmacology 58 (1992): 251. http://dx.doi.org/10.1016/s0021-5198(19)49246-9.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Newman, Francis, Murray B. Stein, Joan R. Trettau, Richard Coppola y Thomas W. Uhde. "Quantitative electroencephalographic (EEG) effects of caffeine in panic disorder". Biological Psychiatry 25, n.º 7 (abril de 1989): A187. http://dx.doi.org/10.1016/0006-3223(89)91865-9.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Gianlorenco, Anna Carolyna L., Paulo S. de Melo, Anna Marduy, Angela Yun Kim, Chi Kyung Kim, Hyuk Choi, Jae-Jun Song y Felipe Fregni. "Electroencephalographic Patterns in taVNS: A Systematic Review". Biomedicines 10, n.º 9 (6 de septiembre de 2022): 2208. http://dx.doi.org/10.3390/biomedicines10092208.

Texto completo

Resumen

Transcutaneous auricular vagus nerve stimulation (taVNS) is a newer delivery system using a non-invasive stimulation device placed at the ear. taVNS research is focused on clinical trials showing potential therapeutic benefits, however the neurophysiological effects of this stimulation on brain activity are still unclear. We propose a systematic review that aims to describe the effects of taVNS on EEG measures and identify taVNS parameters that can potentially lead to consistent EEG-mediated biomarkers for this therapy. A systematic literature review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) and the Cochrane handbook for systematic reviews. Clinical trials examining EEG parameters were considered, including absolute and relative power, coherence, degree of symmetry, evoked potentials, and peak frequency of all bands. According to our criteria, 18 studies (from 122 articles) were included. Our findings show a general trend towards increased EEG power spectrum activity in lower frequencies, and changes on early components of the ERP related to inhibitory tasks. This review suggests that quantitative electroencephalography can be used to assess the effects of taVNS on brain activity, however more studies are needed to systematically establish the specific effects and metrics that would reflect the non-invasive stimulation through the auricular branch of the vagus nerve.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Feige, Bernd, Klaus Scheffler, Fabrizio Esposito, Francesco Di Salle, Jürgen Hennig y Erich Seifritz. "Cortical and Subcortical Correlates of Electroencephalographic Alpha Rhythm Modulation". Journal of Neurophysiology 93, n.º 5 (mayo de 2005): 2864–72. http://dx.doi.org/10.1152/jn.00721.2004.

Texto completo

Resumen

Neural correlates of electroencephalographic (EEG) alpha rhythm are poorly understood. Here, we related EEG alpha rhythm in awake humans to blood-oxygen-level-dependent (BOLD) signal change determined by functional magnetic resonance imaging (fMRI). Topographical EEG was recorded simultaneously with fMRI during an open versus closed eyes and an auditory stimulation versus silence condition. EEG was separated into spatial components of maximal temporal independence using independent component analysis. Alpha component amplitudes and stimulus conditions served as general linear model regressors of the fMRI signal time course. In both paradigms, EEG alpha component amplitudes were associated with BOLD signal decreases in occipital areas, but not in thalamus, when a standard BOLD response curve (maximum effect at ∼6 s) was assumed. The part of the alpha regressor independent of the protocol condition, however, revealed significant positive thalamic and mesencephalic correlations with a mean time delay of ∼2.5 s between EEG and BOLD signals. The inverse relationship between EEG alpha amplitude and BOLD signals in primary and secondary visual areas suggests that widespread thalamocortical synchronization is associated with decreased brain metabolism. While the temporal relationship of this association is consistent with metabolic changes occurring simultaneously with changes in the alpha rhythm, sites in the medial thalamus and in the anterior midbrain were found to correlate with short time lag. Assuming a canonical hemodynamic response function, this finding is indicative of activity preceding the actual EEG change by some seconds.

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Liu, Chien Wei, Ching Sung Wang, Kai Jen Chuang, Chia Chi Lo y Chien Tsu Chen. "Electroencephalographic Study of Essential Oils for Stress Relief". Applied Mechanics and Materials 437 (octubre de 2013): 1085–88. http://dx.doi.org/10.4028/www.scientific.net/amm.437.1085.

Texto completo

Resumen

Nowadays, electroencephalogram (EEG) is widely used in medical applications. Besides the examination for brain diseases, EEG is used to observe how the surroundings affect peoples emotion. There are many essential oils, and most claim that they are effective in soothing soul and calming. Currently, there is no related EEG scientific experiment to verify this claim, This study attempted to understand whether common essential oils for stress relief have actual emotional relaxation effects on the human brain by EEG observation; the level of efficacy was also observed. From the results of this study, rose essential oil had the best effect of stress relief and relaxation in both genders (P<0.05). It suggested that peppermint essential oil had the best effect of relaxation in male (P<0.05) and rose essential oil had the best effect of relaxation in females (P<0.05) when it was analyzed by gender.

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Hyde, Thomas M., Helene A. Emsellem, Christopher Randolph, Kenneth C. Rickler y Daniel R. Weinberger. "Electroencephalographic Abnormalities in Monozygotic Twins with Tourette's Syndrome". British Journal of Psychiatry 164, n.º 6 (junio de 1994): 811–17. http://dx.doi.org/10.1192/bjp.164.6.811.

Texto completo

Resumen

The association of attentional, neuropsychological, and behavioural abnormalities with Tourette's syndrome (TS) suggests that the abnormal function of the disorder extends beyond the motor circuits of the basal ganglia. To explore this possibility we studied, with conventional 18-channel electroencephalography, monozygotic twins ranging from 8 to 26 years of age, where at least one member of the twin pair suffered from TS. In nine out of the 11 twin pairs that differed in clinical severity of the tic disorder, the twin with the more severe course of illness had a significantly more abnormal electroencephalogram (EEG) by qualitative visual analysis. Most of the differences were due to excessive frontocentral theta activity, suggesting dysfunction outside the basal ganglia. There was also a significant relationship between a lower global neuropsychological testing score and a worse overall EEG. In eight of nine twin sets with different global neuropsychological testing scores, the twin with the lower score had a worse EEG. A similar relationship was found between birth weight and overall EEG quality. In the nine sets that differed in birth weight, the twin with a lower birth weight had a worse EEG in seven of the sets. The EEG findings are unlikely to be a medication effect because the same result was seen in the six twin pairs who had been medication-free for at least six months before entry into the study. The origin of this slowing may relate to the interaction between environmental insults to the central nervous system and the genetic component of TS, an interaction producing damage to the cortex, thalamus, or both.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Jones, Keith S., Matthew S. Middendorf, Gloria Calhoun y Grant McMillan. "Evaluation of an Electroencephalographic-Based Control Device". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 42, n.º 5 (octubre de 1998): 491–95. http://dx.doi.org/10.1177/154193129804200510.

Texto completo

Resumen

Electroencephalographic (EEG)-based control devices are one of several emerging technologies that will provide operators with a variety of new hands-free control options. In general, EEG-based control translates brain electrical activity into a control signal. The system evaluated in this study uses the steady-state visual evoked response for system control. The luminance of selectable items on a computer display was modulated at different frequencies. The operator's choice between these items was identified by detecting which frequency pattern was dominant in the visual evoked brain activity. One objective of this study was to characterize the performance of this human-machine system. In addition, two candidate control frequencies were evaluated. The results are encouraging. Participants were able to use this form of EEG-based control and performance was stable. Participants averaged over 90 percent correct selections. Future development will focus on increasing the speed and accuracy with which this novel hands-free controller can be utilized.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Yen, Sheng-Bou, Hsiao-Yu Lee y Shyh-Yueh Cheng. "ELECTROENCEPHALOGRAPHIC ASSESSMENT OF HUMAN RELIABILITY ON VISUAL RESPONSE TASK". Biomedical Engineering: Applications, Basis and Communications 22, n.º 01 (febrero de 2010): 61–70. http://dx.doi.org/10.4015/s101623721000175x.

Texto completo

Resumen

Electrophysiological correlates of human reliability in visual response tasks were investigated in 16 healthy subjects using electroencephalographic (EEG) spectral power and event-related potentials (ERP). Human reliability was first determined by calculating individual reaction accuracy in order to split the entire group into high reliability (HR) and low reliability (LR) subgroups, each with eight subjects. The EEG activities of testing subjects were measured at rest condition for 5 min, and during a modified Eriksen flanker task. Artifact-free EEG segments were used to compute the distribution of EEG at varied frequency bands as well as to detect peak and latency of ERPs of the flanker task. Our results showed that subjects with LR exhibited higher alpha band EEG power at the frontal recording site. Additionally, LR group revealed lower P300 amplitude and predominantly longer P300 latency at centro-parietal recording site than those of the HR group. These findings implied that higher alpha band EEG power at frontal and smaller amplitude, longer latency P300 component of ERP measures at centro-parietal might reveal the trait of lower reliability in healthy controls during visual tasks.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Ayodele, Kayode P., Wisdom O. Ikezogwo y Anthony A. Osuntuyi. "Empirical Characterization of the Temporal Dynamics of EEG Spectral Components". International Journal of Online and Biomedical Engineering (iJOE) 16, n.º 15 (15 de diciembre de 2020): 80. http://dx.doi.org/10.3991/ijoe.v16i15.16663.

Texto completo

Resumen

The properties of time-domain electroencephalographic data have been studied extensively. There has however been no attempt to characterize the temporal evolution of resulting spectral components when successive segments of electroencephalographic data are decomposed. We analysed resting-state scalp electroencephalographic data from 23 subjects, acquired at 256 Hz, and transformed using 64-point Fast Fourier Transform with a Hamming window. KPSS and Nason tests were administered to study the trend- and wide sense stationarity respectively of the spectral components. Their complexities were estimated using fuzzy entropy. Thereafter, the rosenstein algorithm for dynamic evolution was applied to determine the largest Lyapunov exponents of each component’s temporal evolution. We found that the evolutions were wide sense stationary for time scales up to 8 s, and had significant interactions, especially between spectral series in the frequency ranges 0-4 Hz, 12-24 Hz, and 32-128 Hz. The highest complexity was in the 12-24 Hz band, and increased monotonically with scale for all band sizes. However, the complexity in higher frequency bands changed more rapidly. The spectral series were generally non-chaotic, with average largest Lyapunov exponent of 0. The results show that significant information is contained in all frequency bands, and that the interactions between bands are complicated and time-varying.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Harada, Hirofumi, Fumihide Rikimaru, Takashi Mori, Masahiro Tanaka, Kimio Shiraishi y Toshihiko Kato. "Electroencephalographic Changes during Intravenous Olfactory Stimulation in Humans". Clinical Electroencephalography 33, n.º 4 (octubre de 2002): 189–92. http://dx.doi.org/10.1177/155005940203300410.

Texto completo

Resumen

The intravenous olfaction test with thiamin propyl disulfide (TPD) is a simple procedure widely used in Japan. An olfactory stimulus is provided by intravenous injection of TPD (2 ml) over the course of 20 sec. The subject smells n-propyl mercaptan (a decomposition product of TPD discharged from the blood into alveoli) in expired air after treatment. In this preliminary study we recorded electroencephalograms (EEGs) in normal subjects during three stages: 1) eyes-closed rest (prestimulus), 2) olfactory sensation after TPD injection, and 3) disappearance of sensation. In each of these stages, we calculated and compared EEG powers according to the band components of each electrode position. This study was designed a) to evaluate by frequency analysis EEG changes during olfactory sensation after TPD injection, and b) to identify the most significant changes in EEG power according to frequency band and electrode location. During the intravenous olfactory stimulation, alpha 2 and beta 2 waves were activated over the frontal and temporal regions. After disappearance of olfactory sensation, these waves decreased in the same regions. EEG powers returned to prestimulus levels.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Mizrahi, Eli M. "Electroencephalographic-Video Monitoring in Neonates, Infants, and Children". Journal of Child Neurology 9, n.º 1_suppl (octubre de 1994): S46—S56. http://dx.doi.org/10.1177/0883073894009001091.

Texto completo

Resumen

Electroencephalographic (EEG)-video monitoring is a valuable tool in the evaluation and management of neonates, infants, and children suspected of having seizures or those with confirmed epilepsy. Monitoring may provide the basis for detection, characterization, and quantification of seizures in each of these age groups. The basic functional components of monitoring include: EEG, polygraphic measures, video, and synchronization devices that assure that all recorded modalities can be precisely correlated in time. Monitoring techniques may vary depending on patient age, clinical condition, and clinical questions to be addressed. Specially designed instrumentation is required to perform monitoring; however, the role of the technologist is central in conducting a study with maximum clinical yield in the most efficient manner. The clinical neurophysiologist must recognize the specific objectives of each monitoring study and appreciate the age-dependent features of the EEG and the types of clinical paroxysmal events that may occur at different ages. Neonates, infants, and older children all demonstrate special features to be considered in the conduct and analysis of EEG-video monitoring. (J Child Neurol 1994;9(Suppl):S46-S56).

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Pernet, Cyril R., Nicolas Chauveau, Carl Gaspar y Guillaume A. Rousselet. "LIMO EEG: A Toolbox for Hierarchical LInear MOdeling of ElectroEncephaloGraphic Data". Computational Intelligence and Neuroscience 2011 (2011): 1–11. http://dx.doi.org/10.1155/2011/831409.

Texto completo

Resumen

Magnetic- and electric-evoked brain responses have traditionally been analyzed by comparing the peaks or mean amplitudes of signals from selected channels and averaged across trials. More recently, tools have been developed to investigate single trial response variability (e.g., EEGLAB) and to test differences between averaged evoked responses over the entire scalp and time dimensions (e.g., SPM, Fieldtrip). LIMO EEG is a Matlab toolbox (EEGLAB compatible) to analyse evoked responses over all space and time dimensions, while accounting for single trial variability using a simple hierarchical linear modelling of the data. In addition, LIMO EEG provides robust parametric tests, therefore providing a new and complementary tool in the analysis of neural evoked responses.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Electroencephalographic (EEG)"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros