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Literatura académica sobre el tema "Tremor amplitude"

Autor: Grafiati

Publicado: 4 de junio de 2021

Última modificación: 19 de febrero de 2023

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Artículos de revistas sobre el tema "Tremor amplitude"

Kreiman, Jody, Brian Gabelman y Bruce R. Gerratt. "Perception of Vocal Tremor". Journal of Speech, Language, and Hearing Research 46, n.º 1 (febrero de 2003): 203–14. http://dx.doi.org/10.1044/1092-4388(2003/016).

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Vocal tremors characterize many pathological voices, but acoustic-perceptual aspects of tremor are poorly understood. To investigate this relationship, 2 tremor models were implemented in a custom voice synthesizer. The first modulated fundamental frequency (F0) with a sine wave. The second provided irregular modulation. Control parameters in both models were the frequency and amplitude of the F0 modulating waveform. Thirty-two 1-s samples of /a/, produced by speakers with vocal pathology, were modeled in the synthesizer. Synthetic copies of each vowel were created by using tremor parameters derived from different features of F0 versus time plots of the natural stimuli or by using parameters chosen to match the original stimuli perceptually. Listeners compared synthetic and original stimuli in 3 experiments. Sine wave and irregular tremor models both provided excellent matches to subsets of the voices. The perceptual importance of the shape of the modulating waveform depended on the severity of the tremor, with the choice of tremor model increasing in importance as the tremor increased in severity. The average frequency deviation from the mean F0 proved a good predictor of the perceived amplitude of a tremor. Differences in tremor rates were easiest to hear when the tremor was sinusoidal and of small amplitude. Differences in tremor rate were difficult to judge for tremors of large amplitude or in the context of irregularities in the pattern of frequency modulation. These results suggest that difference limens are larger for modulation rates and amplitudes when the tremor pattern is complex. Further, tremor rate, regularity, and amplitude interact, so that the perceptual importance of any one dimension depends on values of the others.

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Sabah najim, Nawras, Abdulnasir H. Ameer y Azad A. Mohammed. "The Electrophysiological Perspectives of Essential, Enhanced Physiological, and Physiological Tremors". Journal of the Faculty of Medicine Baghdad 64, n.º 2 (24 de julio de 2022): 86–90. http://dx.doi.org/10.32007/jfacmedbagdad.6421921.

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Abstract: Background: The most frequent movement issue seen in clinical practice is tremors. It is known as repetitive, involuntary oscillations. The diagnostic process for tremor patients can be time-consuming and complicated, as the identification of “Essential Tremor” and its distinction from other types of tremor. Objectives: This study aimed to describe the electrophysiological findings of essential, enhanced physiological, and physiological tremors, using surface electromyography and an accelerometer. Patients and Methods: The study included 24 patients with essential tremors, 10 patients with enhanced physiological tremors, and 10 patients with physiological tremors. We assessed the frequency, amplitude, and muscular contraction pattern of tremors during rest, posture, and a 1 kg load. Results: The tremor frequency of essential tremor patients was about 4.2-10.1 Hertz, while enhanced physiological tremor and physiological tremor were increased to 6.1–12.7 Hertz and 5.1-10.2 Hertz, respectively. The essential tremor group muscle contraction pattern was predominantly synchronous, as do all enhanced physiological, and physiological tremor patients, but with more fine low amplitude muscle bursts. By varying the tremor frequency and the weight load effect, tremor analysis could discriminate essential from enhanced physiological, and physiological tremors. Conclusions: The tremor analysis using surface electromyography and an accelerometer is sufficient to differentiate between essential tremors, enhanced physiological tremors, and physiological tremors.

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Samotus, Olivia, Jack Lee y Mandar Jog. "Developing a Consistent, Reproducible Botulinum Toxin Type A Dosing Method for Upper Limb Tremor by Kinematic Analysis". Toxins 13, n.º 4 (8 de abril de 2021): 264. http://dx.doi.org/10.3390/toxins13040264.

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Botulinum toxin type A (BoNT-A) injection patterns customized to each patient’s unique tremor characteristics produce better efficacy and lower adverse effects compared to the fixed-muscle-fixed-dose approach for Essential Tremor (ET) and Parkinson’s disease (PD) tremor therapy. This article outlined how a kinematic-based dosing method to standardize and customize BoNT-A injections for tremors was developed. Seven ET and eight PD participants with significant tremor reduction and minimal perceived weakness using optimized BoNT-A injections determined by clinical and kinematic guidance were retrospectively selected to develop the kinematic-based dosing method. BoNT-A dosages allocated per joint were paired to baseline tremor amplitudes per joint. The final kinematic-based dosing method was prospectively utilized to validate BoNT-A injection pattern selection without clinical/visual assessments in 31 ET and 47 PD participants with debilitating arm tremors (totaling 122 unique tremor patterns). Whole-arm kinematic tremor analysis was performed at baseline and 6-weeks post-injection. Correlation and linear regression analyses between baseline tremor amplitudes and the change in tremor amplitude 6-weeks post-injection, with BoNT-A dosages per joint, were performed. Injection patterns determined using clinical assessment and interpretation of kinematics produced significant associations between baseline tremor amplitudes and optimized BoNT-A dosages in all joints. The change in elbow tremor was only significantly associated with the elbow total dose as the change in the wrist and shoulder tremor amplitudes were not significantly associated with the wrist and shoulder dosages from the selected 15 ET and PD participants. Using the kinematic-based dosing method, significant associations between baseline tremor amplitudes and the change (6-weeks post-first treatment) in tremor at each joint with BoNT-A dosages for all joints was observed in all 78 ET and PD participants. The kinematic-based dosing method provided consistency in dose selection and subsequent tremor reduction and can be used to standardize tremor assessments for whole-arm tremor treatment planning.

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HEO, JAE-HOON, HYEONG-MIN JEON, EUI-BUM CHOI, DO-YOUNG KWON y GWANG-MOON EOM. "EFFECT OF SENSORY ELECTRICAL STIMULATION ON RESTING TREMORS IN PATIENTS WITH PARKINSON’S DISEASE AND SWEDDs". Journal of Mechanics in Medicine and Biology 19, n.º 07 (noviembre de 2019): 1940033. http://dx.doi.org/10.1142/s0219519419400335.

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Patients with scans without evidence of dopaminergic deficits (SWEDDs) show symptoms (e.g., tremors) similar to those of Parkinson’s disease (PD) patients, so they are often misdiagnosed. Sensory electrical stimulation (SES) was reported to suppress essential tremor in patients, but SES was never applied to patients with PD and SWEDDs. As the pathophysiological mechanisms of PD and SWEDDs are likely to be different, we hypothesized that the effect of SES would also be different in the two patient groups. This study aimed to test that hypothesis. Fourteen patients with PD and nine with SWEDDs participated in this study. Three wrist muscles were stimulated for 15[Formula: see text]s using SES with a stimulation intensity lower than the motor threshold. Angular motion of the index finger was measured via a triaxial gyrosensor before, during, and after stimulation. Outcome measures included the amplitude and peak frequency of the angular motion of the index finger. Tremor amplitude decreased during and after SES in patients with PD ([Formula: see text]). However, tremor amplitudes during and after SES were not different from the base level in SWEDDs patients. The peak frequency of tremors temporarily decreased during stimulation in PD patients, but not in SWEDDs patients. SES suppressed tremors in patients with PD, but not with SWEDDs. The results could help understand the pathophysiological differences of tremors between PD and SWEDDs.

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Dirkx, Michiel F., Heidemarie Zach, Bastiaan R. Bloem, Mark Hallett y Rick C. Helmich. "The nature of postural tremor in Parkinson disease". Neurology 90, n.º 13 (23 de febrero de 2018): e1095-e1103. http://dx.doi.org/10.1212/wnl.0000000000005215.

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ObjectiveTo disentangle the different forms of postural tremors in Parkinson disease (PD).MethodsIn this combined observational and intervention study, we measured resting and postural tremor characteristics in 73 patients with tremulous PD by using EMG of forearm muscles. Patients were measured both “off” medication (overnight withdrawal) and after dispersible levodopa-benserazide 200/50 mg. We performed an automated 2-step cluster analysis on 3 postural tremor characteristics: the frequency difference with resting tremor, the degree of tremor suppression after posturing, and the dopamine response.ResultsThe cluster analysis revealed 2 distinct postural tremor phenotypes: 81% had re-emergent tremor (amplitude suppression, frequency difference with resting tremor 0.4 Hz, clear dopamine response) and 19% had pure postural tremor (no amplitude suppression, frequency difference with resting tremor 3.5 Hz, no dopamine response). This finding was manually validated (accuracy of 93%). Pure postural tremor was not associated with clinical signs of essential tremor or dystonia, and it was not influenced by weighing.ConclusionThere are 2 distinct postural tremor phenotypes in PD, which have a different pathophysiology and require different treatment. Re-emergent tremor is a continuation of resting tremor during stable posturing, and it has a dopaminergic basis. Pure postural tremor is a less common type of tremor that is inherent to PD, but has a largely nondopaminergic basis.

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Milanov, Ivan. "Clinical and Electromyographic Examinations of Patients with Essential Tremor". Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 27, n.º 1 (febrero de 2000): 65–70. http://dx.doi.org/10.1017/s0317167100052008.

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ABSTRACT:Background:It is believed that no clinical differences exist among essential, familial and senile tremor, or between the tremor with synchronous or alternating electromyographic activity. The aim of this study was to evaluate the clinical and electromyographic findings in a large group of patients with different types of essential tremor.Methods:Two hundred and twenty patients with sporadic, familial or senile variants of essential tremor were examined. According to the electromyographic activity recorded from the antagonistic muscles, the patients were subdivided into a group with synchronous (SYN) and a group with alternating (ALT) activity. The historical aspects of the disease were noted, and a detailed neurological examination was performed.Results:A widespread tremor involving upper and lower limbs and 3-4 different anatomical regions was typical for familial tremor. It also had higher amplitude than the sporadic and senile tremor. ALT tremor had a higher amplitude and longer burst duration than SYN and more often involved lower limbs. Rest tremor was common in the ALT group. Overall, ALT tremor was more common than previously supposed.Conclusion:The familial and ALT tremors are more disabling than other types of essential tremor. Since electromyographic ALT activity is common in essential tremor, its presence does not reliably distinguish essential and Parkinsonian tremor.

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Kim, Jeonghee, Thomas Wichmann, Omer T. Inan y Stephen P. DeWeerth. "Analyzing the Effects of Parameters for Tremor Modulation via Phase-Locked Electrical Stimulation on a Peripheral Nerve". Journal of Personalized Medicine 12, n.º 1 (8 de enero de 2022): 76. http://dx.doi.org/10.3390/jpm12010076.

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(1) Background: Non-invasive neuromodulation is a promising alternative to medication or deep-brain stimulation treatment for Parkinson’s Disease or essential tremor. In previous work, we developed and tested a wearable system that modulates tremor via the non-invasive, electrical stimulation of peripheral nerves. In this article, we examine the proper range and the effects of various stimulation parameters for phase-locked stimulation. (2) Methods: We recruited nine participants with essential tremor. The subjects performed a bean-transfer task that mimics an eating activity to elicit kinetic tremor while using the wearable stimulation system. We examined the effects of stimulation with a fixed duty cycle, at different stimulation amplitudes and frequencies. The epochs of stimulation were locked to one of four phase positions of ongoing tremor, as measured with an accelerometer. We analyzed stimulation-evoked changes of the frequency and amplitude of tremor. (3) Results: We found that the higher tremor amplitude group experienced a higher rate of tremor power reduction (up to 65%) with a higher amplitude of stimulation when the stimulation was applied at the ±peak of tremor phase. (4) Conclusions: The stimulation parameter can be adjusted to optimize tremor reduction, and this study lays the foundation for future large-scale parameter optimization experiments for personalized peripheral nerve stimulation.

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Berbakov, Lazar, Čarna Jovanović, Marina Svetel, Jelena Vasiljević, Goran Dimić y Nenad Radulović. "Quantitative Assessment of Head Tremor in Patients with Essential Tremor and Cervical Dystonia by Using Inertial Sensors". Sensors 19, n.º 19 (30 de septiembre de 2019): 4246. http://dx.doi.org/10.3390/s19194246.

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Tremor is most common among the movement disabilities that affect older people, having a prevalence rate of 4.6% in the population older than 65 years. Despite this, distinguishing different types of tremors is clinically challenging, often leading to misdiagnosis. However, due to advances in microelectronics and wireless communication, it is now possible to easily monitor tremor in hospitals and even in home environments. In this paper, we propose an architecture of a system for remote health-care and one possible implementation of such system focused on head tremor monitoring. In particular, the aim of the study presented here was to test new tools for differentiating essential tremor from dystonic tremor. To that aim, we propose a number of temporal and spectral features that are calculated from measured gyroscope signals, and identify those that provide optimal differentiation between two groups. The mean signal amplitude feature results in sensitivity = 0.8537 and specificity = 0.8039 in distinguishing patients having cervical dystonia with or without tremor. In addition, mean signal amplitude was shown to be significantly higher in patients with essential tremor than in patients with cervical dystonia, whereas the mean peak frequency is not different between two groups.

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Cichaczewski, Ederson, Renato P. Munhoz, Joaquim M. Maia, Percy Nohama, Edison M. Nóvak y Helio A. Teive. "Electrophysiologic characteristics of tremor in Parkinson?s disease and essential tremor". Arquivos de Neuro-Psiquiatria 72, n.º 4 (abril de 2014): 301–6. http://dx.doi.org/10.1590/0004-282x20140006.

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Tremor in essential tremor (ET) and Parkinson’s disease (PD) usually present specific electrophysiologic profiles, however amplitude and frequency may have wide variations. Objective: To present the electrophysiologic findings in PD and ET. Method: Patients were assessed at rest, with posture and action. Seventeen patients with ET and 62 with PD were included. PD cases were clustered into three groups: predominant rest tremor; tremor with similar intensity at rest, posture and during kinetic task; and predominant kinetic tremor. Results: Patients with PD presented tremors with average frequency of 5.29±1.18 Hz at rest, 5.79±1.39 Hz with posture and 6.48±1.34 Hz with the kinetic task. Tremor in ET presented with an average frequency of 5.97±1.1 Hz at rest, 6.18±1 Hz with posture and 6.53±1.2 Hz with kinetic task. Seven (41.2%) also showed rest tremor. Conclusion: The tremor analysis alone using the methodology described here, is not sufficient to differentiate tremor in ET and PD.

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Mostile, Giovanni, Robert Fekete, Joseph P. Giuffrida, Toby Yaltho, Anthony Davidson, Alessandra Nicoletti, Mario Zappia y Joseph Jankovic. "Amplitude fluctuations in essential tremor". Parkinsonism & Related Disorders 18, n.º 7 (agosto de 2012): 859–63. http://dx.doi.org/10.1016/j.parkreldis.2012.04.019.

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Tesis sobre el tema "Tremor amplitude"

Keogh, Justin W. L. y n/a. "Constraints on the Control of Physiological Tremor". Griffith University. School of Physiotherapy and Exercise Science, 2006. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20070208.110453.

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This thesis sought to: 1) examine the effect of a number of organism and task constraints on the control of two forms of physiological tremor, namely postural and finger-pinch force tremor; and 2) determine if the expected constraint-related changes in tremor output were associated with alterations in the control strategy utilised by the performer. The organism constraints were age and resistance-training (for both forms of tremor), while the task constraints were visual feedback, target size and limb preference (postural tremor) and mean force, target shape and limb preference (force tremor). The postural (index finger) tremor amplitude of young adults was significantly greater in the augmented vision (AV) than normal vision (NV) conditions and when using the non-preferred than preferred limb. Even greater differences/changes in postural tremor amplitude were observed as a function of aging and training. Older adults had significantly more index finger tremor amplitude than young adults. Regardless, the older adults who completed a six weeks program of unilateral strength- or coordination-training were able to significantly reduce their tremor amplitude. Although the training-related reductions in tremor amplitude were of a greater magnitude for the trained than untrained limb, a significant reduction in the tremor amplitude of the untrained limb was also observed for the coordination-training group. All of these significant differences/changes in tremor amplitude were associated with significant changes in a number of other dependent variables. For example, the task- and age-related increases in tremor amplitude were primarily a result of greater 8-12 Hz tremor power and were associated with increased EMG activity/co-activation of the extensor digitorum (ED) and flexor digitorum superficialis (FDS) muscles and a significant reduction in intra-limb (index finger-hand and forearm-upper arm) coupling. The significant reductions in tremor amplitude observed for the resistance-trained older adults was a result of a significant decline in 8-12 Hz power and were associated with a significant reduction in ED and FDS co-activation. However, no significant change in intra-limb coupling was observed. The overall trends observed in the results for the finger-pinch force tremor experiments were similar to those for postural tremor. Older adults had significantly more finger-pinch force tremor (i.e. force variability and targeting error) than young adults, although older adults who performed six weeks of unilateral strength-training were able to significantly reduce the force variability and targeting error of the trained limb. No significant training-related reduction in force tremor was however observed for the untrained limb. The significant age-related increase in force tremor was a result of greater low frequency (less than 2 Hz) power and was associated with a significant loss of inter-digit force sharing and coupling as well as tactile sensitivity. Interestingly, the training-related decreases in force tremor were not associated with significant changes in any of the frequency, sharing or coupling measures. Collectively, the results of the five experiments contained in this thesis add much to our understanding of postural and force tremor. Results indicated that numerous task and organism constraints can have a substantial effect on the resulting tremor output. Furthermore, the task- and age-related differences in the power spectral, muscle activity and coupling measures suggested that the changes in tremor output were the result of the use of an altered (sub-optimal) control strategy. The age-related increase in postural and force tremor amplitude may therefore reflect not only an overall decline in neuromuscular system function, but also the relative inability of older adults to effectively coordinate the output of numerous degrees of freedom (limb segments). The effect of the aging process on tremor output was somewhat reversible, with the older adults who performed resistance-training significantly improving their control of both postural and force tremor. There was some evidence that resistance-training could produce cross-education effects in older adults, although these were only statistically significant for postural tremor amplitude in the coordination-training group and for wrist flexion strength in the strength-training group. The relative brevity of the training program (6 weeks) and the observable cross-education effects suggest that the reduction in tremor amplitude and increases in strength were primarily a result of neural adaptations. Such findings further support the prescription of resistance-training for improving physical function in older individuals.

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Meshack, Rubia Parwyn. "The effects of weights on the amplitude and frequency of postural hand tremor in people with Parkinson's disease". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63339.pdf.

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Ardiani, Mei Astrid y 安蒂美. "Duration-amplitude scaling of volcanic tremor recorded at Mt. Erebus volcano, Antarctica". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/9p7293.

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碩士
國立中央大學
地球科學學系
106
Most phenomena in nature show a relationship between their numbers and their sizes. This relationship can be used to identify their source processes. In this respect, we investigate duration-amplitude distribution for 278 tremor events during May 2002-April 2004 recorded at Erebus volcano, Antarctica. We compute reduced displacement (

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Capítulos de libros sobre el tema "Tremor amplitude"

Rabelo, Amanda, João Paulo Folador, Ana Paula Bittar, Luiza Maire, Samila Costa, Alice Rueda, S. Krishnan, Viviane Lima, Rodrigo M. A. Almeida y Adriano O. Andrade. "Low Amplitude Hand Rest Tremor Assessment in Parkinson’s Disease Based on Linear and Nonlinear Methods". En XXVII Brazilian Congress on Biomedical Engineering, 301–6. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-70601-2_46.

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Šilený, Jan. "The Mechanism of Small Mining Tremors from Amplitude Inversion". En Seismicity in Mines, 309–24. Basel: Birkhäuser Basel, 1989. http://dx.doi.org/10.1007/978-3-0348-9270-4_4.

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Deuschl, G., J. Timmer, H. Genger, C. Gantert, C. H. Lücking y J. Honerkamp. "Frequency, Amplitude, and Waveform Characteristics of Physiologic and Pathologic Tremors". En Instrumental Methods and Scoring in Extrapyramidal Disorders, 93–100. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-78914-4_9.

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Dik, Olga E. y Alexander D. Nozdrachev. "Chapter 6. Mechanisms of changes in dynamic complexity of involuntary oscillations of the human hand with movement disorders". En Mechanisms of changes in dynamical complexity of physiological signal patterns, 99–131. St. Petersburg State University, 2019. http://dx.doi.org/10.21638/11701/9785288059322.07.

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The sixth chapter examines the mechanisms of changes in the dynamic complexity of hand tremor with an increase in the degree of motor disorders. For this, multifractal and wavelet properties of involuntary oscillations that arise during the performance of certain motor tasks by a healthy person and a person with varying degrees of motor pathology are investigated. It was shown that clinical manifestations of pathological tremor correlate, firstly, with a significant increase in the global energy of the wavelet spectrum and, secondly, with a decrease in the width of the singularity spectrum. At the same time, an improvement in the functional state (a decrease in the amplitude of a pathological tremor) corresponds to a decrease in long-term correlations and an increase in the randomness of up-down patterns, which corresponds to a partial shift of the singularity spectrum into the range of values typical for a tremor of the hand of a healthy person. The mechanism for reducing the dynamic complexity of patterns of involuntary oscillations of the human hand with an increase in the degree of motor disorders is based on a decrease in the contribution of strong fluctuations, accompanied by the appearance of long-term correlations of sequential values of tremor. The considered features in changes in tremor patterns make it possible to quantify the degree of movement disorders and can be used to facilitate the differential diagnosis of the parkinsonian and essential tremor in complex clinical cases.

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Youssef, Paul E., Kenneth J. Mack y Kelly D. Flemming. "Classification and Approach to Movement Disorders". En Mayo Clinic Neurology Board Review, editado por Kelly D. Flemming, 571–75. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197512166.003.0068.

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Movement disorders are conventionally divided into 2 major categories. Hyperkinetic movement disorders (also called dyskinesias) are excessive, often repetitive, involuntary movements that intrude into the normal flow of motor activity. This category includes chorea, dystonia, myoclonus, stereotypies, tics, and tremor. Hypokinetic movement disorders are akinesia (lack of movement), hypokinesia (reduced amplitude of movement), bradykinesia (slow movement), and rigidity. Parkinsonism is the most common hypokinetic movement disorder. In childhood, hyperkinetic disorders are common, whereas hypokinetic movement disorders are relatively uncommon.

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Ahlskog, J. Eric. "Which Drug for Parkinsonism? Walking, Stiffness, Tremor, and Slowness". En Dementia with Lewy Body and Parkinson's Disease Patients. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199977567.003.0011.

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In Chapters 1 and 4, we briefly summarized the symptoms of parkinsonism. Parkinsonism implies movement problems that are typical of Parkinson’s disease. They remain treatment issues during the lifetime of people with Parkinson’s disease, even if dementia develops. Similarly, parkinsonism also typically occurs in DLB, although to variable degrees. In these disorders parkinsonism primarily reflects low brain dopamine levels and improves with dopamine replacement therapy, often markedly. Parkinsonism occurs when a region of the brain called the basal ganglia ceases to work properly (see Figure 4.2 in Chapter 4). As discussed in Chapter 4, the substantia nigra is a crucial regulator of basal ganglia activity, which is mediated by dopamine release in the striatum. The substantia nigra degenerates in these Lewy disorders and, as a result, brain dopamine declines. With a decline in dopamine, movement slows. Bradykinesia is the medical term for such slowness. This manifests as not only slowed movement but also less movement and smaller than normal movements. Unconscious automatic movements, such as blinking or arm swing, diminish. A unique tremor of the hands (sometimes legs) often develops when these limbs are in a relaxed position (rest tremor). For unknown reasons, the brain is not affected symmetrically, hence, neither is the body. Typically, one side of the body is much more impaired than the other. The extent to which these symptoms develop differs from person to person and includes various combinations of the following components. The slowness may be apparent on one or both sides of the body. For example, one leg may lag behind when walking. The overall appearance is characterized by moving much slower than expected for one’s age. The person feels as if they are moving in molasses—everything slows down. Many of our daily activities involve repeated small movements, such as writing or brushing teeth. In the Lewy conditions of DLB and PDD, the size (amplitude) of repetitive movements diminishes, impairing the activity. This is exemplified by the small handwriting of someone with parkinsonism, termed micrographia. Clinicians assess repetitive motor function by asking the patient to repetitively tap the thumb and index finger.

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Miocinovic, Svjetlana, Pravin Khemani, Rebecca Whiddon y Shilpa Chitnis. "Improved Outcome on Interleaved Deep Brain Stimulation Settings". En Deep Brain Stimulation, editado por Laura S. Surillo Dahdah, Padraig O’Suilleabhain, Hrishikesh Dadhich, Mazen Elkurd, Shilpa Chitnis y Richard B. Dewey, 155–60. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780190647209.003.0032.

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Interleaving is a DBS programming method whereby two sets of stimulation parameters are applied interchangeably (on a millisecond level). This chapter describes a patient with Parkinson disease who was implanted with subthalamic nucleus deep brain stimulation but achieved suboptimal tremor control with conventional programming (monopolar, double monopolar, or bipolar settings). Interleaving allowed the dorsal contact to be set to a higher setting, while the contact below was set to a tolerable lower setting. Together, the two contacts provided complete tremor resolution without side effects. It is unknown whether interleaving provides any additional advantage over simply allowing use of different amplitudes at different contacts, but potential mechanisms are discussed.

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Actas de conferencias sobre el tema "Tremor amplitude"

Singh, S. P. N. y C. N. Riviere. "Physiological tremor amplitude during retinal microsurgery". En Proceedings of the IEEE 28th Annual Northeast Bioengineering Conference. IEEE, 2002. http://dx.doi.org/10.1109/nebc.2002.999520.

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Winston, Sam E., Riley C. Dehmer y Timothy A. Doughty. "Parkinsons Disease: Tremor Suppression With Wearable Device". En ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-70910.

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Abstract Parkinson’s Disease (PD) is a neurodegenerative disorder that affects nearly a million people in the United States. Hand tremors are a well-known symptom associated with PD and result in anxiety, frustration, and malnutrition. While there is no cure, several approaches attempt to treat the symptoms. Many are invasive, including the use of pharmaceuticals and surgery [1]. Noninvasive technologies are often cumbersome and do not address the conspicuous nature experiencing tremors in public. This study is motivated by design criteria established from previous research [2], with a goal of an affordable, purely mechanical solution. In both cases, human subject testing echoed lab tests in effective tremor reduction. The extension to a wearable device gives the user the ability to hold or handle any object, or no object, with a significant reduction in tremor. Two separate wearable devices were tested for effectiveness while the simulated user ‘held’ two different objects to simulate different applications. Biomechanical modeling of the human hand informed the development of an adjustable mechanical hand-tremor system for testing. Models of the devices and the hand-device interface were used to simulate the dynamic response of the coupled systems. Each device was secured to the mechanical hand-tremor system and harmonic stimulus and response data was collected over the range of typical tremor frequencies. The results demonstrate the versatility of both designs for reducing the oscillations associated with tremors. The Ratio of Reduction (RoR) was defined to compare the tremor amplitude of the hand-tremor system with and without the device. Both designs were considered effective for each object with a max RoR of 28.09 for Device A and a max RoR of 99.32 for Device B.

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Chanov, N. D., I. S. Antonov y A. V. Li. "COMPARISON OF TREMOR AMPLITUDE IN PATIENTS WITH PARKINSON'S DISEASE BY SEX". En NOVEL TECHNOLOGIES IN MEDICINE, BIOLOGY, PHARMACOLOGY AND ECOLOGY. Institute of information technology, 2022. http://dx.doi.org/10.47501/978-5-6044060-2-1.383-384.

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In this article, a comparative characterization of tremor as a motor symptom in Parkinson's Disease is carried out in patients of different sexes using a non-invasive device, which allows you to objectively assess the amplitude of tremor and determine the presence of a statistically significant difference between the sexes.

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Taheri, Behzad, David Case y Edmond Richer. "Theoretical Development and Experimental Validation of an Adaptive Controller for Tremor Suppression at Musculoskeletal Level". En ASME 2013 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/dscc2013-3954.

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Tremor is a rhythmical and involuntary oscillatory movement of a body part. Mechanical loading via wearable exoskeletons is a non-invasive tremor suppression alternative to medical treatments. In this approach, the challenge is attenuating the tremor without affecting the patient’s intentional motion. An adaptive tremor suppression algorithm was designed to estimate and restrict motion within the tremor frequency band. An experimental setup was designed and developed to simulate the dynamics of a human arm joint with intentional and tremorous motion. The required orthotic suppressive force was applied via a pneumatic cylinder. The algorithm was implemented with a real-time controller and experimental results show tracking of the tremor frequency and a 97% reduction of tremor amplitude at the fundamental frequency.

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Taheri, Behzad, David Case y Edmond Richer. "Active Tremor Estimation and Suppression in Human Elbow Joint". En ASME 2011 Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power and Motion Control. ASMEDC, 2011. http://dx.doi.org/10.1115/dscc2011-6185.

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A new control algorithm was developed for tremor estimation and suppression in a second order linear model of the human elbow joint. An adaptive method developed to estimate a simple harmonic disturbance was generalized for tremorous motion with spectral composition similar to the clinical reports for action tremor. Numerical simulations showed the ability of proposed controller to reduce tremor amplitude without generating significant resistance against voluntary motion of the arm. The designed algorithm can be used in an upper-limb orthosis to suppress debilitating tremorous motion of the arm.

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Kim, Sang Kyong, Hyo Seon Jeon, Han Byul Kim, Ko Keun Kim, Beom Seok Jeon y KwangSuk Park. "Changes in Bilateral Phase Synchronization in Parkinsonian Tremor Related to Amplitude Difference". En Biomedical Engineering. Calgary,AB,Canada: ACTAPRESS, 2013. http://dx.doi.org/10.2316/p.2013.791-159.

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Zamanian, Amir Hosein y Edmond Richer. "Adaptive Disturbance Rejection Controller for Pathological Tremor Suppression With Permanent Magnet Linear Motor". En ASME 2017 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dscc2017-5151.

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This paper presents an adaptive disturbance rejection (ADR) controller developed for the suppression of the pathological tremor in the humans’ wrist. An experimental setup, based on a slotted permanent magnet linear motor (PMLM), was developed to evaluate the ADR’s performance in real-time suppression of the tremor signal recorded from Parkinson’s disease patients. A model-base compensator was utilized to minimize the resistive and cogging forces exhibited by the PMLM. Experimental results showed an average tremor amplitude suppression of 32.61 dB (97.6%) in the first, and 15.23 dB (82.7%) in the second tremor frequency respectively. The average magnitude of the resistance force induced by the system against voluntary motion was 0.36 N. Furthermore, to evaluate the tremor suppression performance of the presented technique the results were compared with two other studies that used pneumatic actuators and magneto-rheological dampers (MRD). The performance of the PMLM was analogous to actively controlled pneumatic actuators and was significantly better than the semi-active controller with MRD.

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Guerrera, Brittany, Samantha Farrow, Gloria Zeng y Sally F. Shady. "Multiple Sclerosis Symptom Analyzer". En ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-66217.

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Multiple Sclerosis (MS) is a chronic neurodegenerative disease of the central nervous system. MS is typically diagnosed between the ages of 20 and 40. There is no known cause of the disease and each individual experiences varying signs and symptoms depending on the severity of their disease. The most common symptoms include tremor, debilitated gait, visual impairment, or cognitive and emotional disturbances. Current methods used to treat MS include oral medication and surgical treatment. The issues with oral medication are the unwanted side effects to otherwise healthy tissue and the lack of patient adherence. Surgical treatment can be invasive and require longer recovery times. An alternate strategy to treat MS is by increasing the knowledge base of the practitioner to potentially treat specific symptoms. Currently, physicians use observations and MRI scans of the brain and spinal cord to help diagnose and track the progression of MS. There are several studies that analyze existing assistive technology to aid in the treatment of MS tremors. Most of these studies did not involve large test groups, therefore it is difficult to prove their validity. Additionally, none of the current devices are able to track symptoms while simultaneously creating medical history records. The goal of the design is to create a new device that will obtain the frequency and amplitude of tremors, while analyzing the effects of temperature and heart rate on the intensity of the tremor. With this data, the device will advance further MS research and lead to better diagnosis and treatment.

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Filpo, Alessandra, Caio Disserol, Bernardo Corrêa de Almeida Teixeira, Kenzo Hokazono y Hélio A. G. Teive. "An Unexpected Smile: risus sardonicus and wing-beating tremor in a first office visit". En XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.505.

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Context: We present a noteworthy reminder of Wilson disease’s classical manifestations, which may become rarer in clinical practice as availability of genetic tests increases, allowing timely diagnosis and treatment. Case report: A 29 year-old woman developed progressive and asymmetric upper limb tremor and dystonia over 1 year, along with speech and feeding impairment in the last two weeks. Examination revealed segmental dystonia with risus sardonicus, open-jaw oromandibular and severe left arm dystonia, along with wing-beating tremor. Bilateral Kayser-Fleischer ring, low serum ceruloplasmin level, high urinary copper level, bilateral putaminal lesions on brain MRI and detection of ATP7B mutation confirmed Wilson disease (WD). A nasoenteric tube was inserted and D-penicillamine was started. Conclusion: This case illustrates the hallmark neuro-ophtalmological signs of WD: wing-beating tremor, risus sardonicus and Kayser-Fleischer ring. The former is probably associated with lesions in the dentato-rubro-thalamic pathway¹ and means a low frequency, high amplitude, posture-induced proximal arm tremor. Risus sardonicus means a fixed smile due to risorius muscle dystonia². Although it is a well-known manifestation of cephalic tetanus, it is also frequent in WD¹. Finally, the Kayser-Fleischer ring is caused by copper accumulation in the Descemet membrane and occurs in almost 100% of patients with neurological WD².

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Thelen, Matthew, Fardeen Mazumder, Linda Zhu, Charlotte Tang y Nathaniel S. Miller. "Reliability Test of Mobile Embedded Accelerometers in Measuring Postural Stability for People With Parkinson’s Disease". En ASME 2022 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/imece2022-94806.

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Abstract Parkinson’s Disease (PD) is the second most common neurodegenerative disease in the United States, affecting at least one million people. The cardinal symptoms of PD are tremor, rigidity, slowed movement, and impaired balance. While some symptoms of PD are responsive to anti-PD medications, other symptoms, are less medication responsive, especially walking and balance. Moreover, daily activities, such as writing, using tools, and walking, affect the quality of life (QoL) of people with PD (PwPD). Monitoring PD symptoms is essential for clinical evaluations and adjusting medication to help maintain QoL for PwPD. we are developing a mobile app to conduct at-home PD symptom monitoring with the goal of providing more timely and frequent measurements of PD symptoms for both patients and clinicians. While the tremor and finger tapping results collected in the mobile app have been discussed in previous publications, this paper focuses on the design and testing of postural stability (balance) tests in the app and the validation of the reliability of the mobile embedded accelerometers. During the test, a dual-purpose shaker was employed to provide vibration in amplitude and frequency range similar to human postural stability signals. A head expander was attached to the shaker and the smartphone holder is screwed to it. The tilt and yaw angles of the smartphone holder are adjustable, therefore the smartphone could be tested in an angled position relative to the shaker. Various types of input signals were tested, including sweep and multiple real postural stability data previously collected from a volunteer. Two models of smartphones were used to measure the signal through multiple trials and the results were compared to the input benchmark signal to verify the accuracy of the smartphone measurements. Besides the evaluation of the time domain raw data, we have also employed several signal processing algorithms to extract postural stability factors, such as the root mean square (RMS) value, the derivative of acceleration, frequency factors, etc., with the goal of identifying the patterns of motion signals which could be used as a summary measures of balance for PD. These signal processing algorithms were used to process raw measurement data from multiple trials, on different input signals, and on different devices. The results were compared, and the consistency of these factors through multiple trials with different smartphone models is tested and summarized. These results help us to find the most reliable measure to be used in the smartphone application. Both the results in raw acceleration signals and calculated factors will be discussed to further the current understanding of the reliability of smartphone measurements with embedded accelerometers.

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