Principles of Electrophysiological Assessments for Movement Disorders
Open Access
- 1 January 2020
- journal article
- review article
- Published by The Korean Movement Disorder Society in Journal of Movement Disorders
- Vol. 13 (1), 27-+
- https://doi.org/10.14802/jmd.19064
Abstract
Electrophysiological studies can provide objective and quantifiable assessments of movement disorders. 'they are useful in the diagnosis of hyperkinetic movement disorders, particularly tremors and myoclonus. The most commonly used measures are surface electromyography (sEMG), electroencephalography (EEG) and accelerometry. Frequency and coherence analyses of sEMG signals may reveal the nature of tremors and the source of the tremors. The effects of voluntary tapping, ballistic movements and weighting of the limbs can help to distinguish between organic and functional tremors. The presence of Bereitschaftspotentials and beta-band desynchronization recorded by EEG before movement onset provide strong evidence for functional movement disorders. EMG burst durations, distributions and muscle recruitment orders may identify and classify myoclonus to cortical, subcortical or spinal origins and help in the diagnosis of functional myoclonus. Organic and functional cervical dystonia can potentially be distinguished by EMG power spectral analysis. Several reflex circuits, such as the long latency reflex, blink reflex and startle reflex, can be elicited with different types of external stimuli and are useful in the assessment of myoclonus, excessive startle and stiff person syndrome. However, limitations of the tests should be recognized, and the results should be interpreted together with clinical observations.Keywords
This publication has 72 references indexed in Scilit:
- Psychogenic parkinsonismJournal of the Neurological Sciences, 2011
- Moving toward “laboratory‐supported” criteria for psychogenic tremorMovement Disorders, 2011
- Myoclonic disorders: a practical approach for diagnosis and treatmentTherapeutic Advances in Neurological Disorders, 2011
- Definition and classification of hyperkinetic movements in childhoodMovement Disorders, 2010
- Axial jerks: a clinical spectrum ranging from propriospinal to psychogenic myoclonusZeitschrift für Neurologie, 2010
- Abnormal sensorimotor plasticity in organic but not in psychogenic dystoniaBrain, 2009
- Electrophysiological features of myoclonus‐dystoniaMovement Disorders, 2008
- Psychogenic propriospinal myoclonusMovement Disorders, 2008
- Unique form of propriospinal myoclonus as a possible complication of an enteropathogenic toxinMovement Disorders, 2003
- Electrophysiological study of diaphragmatic myoclonus.Journal of Neurology, Neurosurgery & Psychiatry, 1995