Motor excitability after the C reflex in cortical reflex myoclonus
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Updated: Jun 27, 2026

Non-invasive Assessment of Changes in Corticomotoneuronal Transmission in Humans
Published on: May 24, 2017
Takenori Uozumi1, Utako Takechi, Kouichiro Yoshinaga
1Department of Neurology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan, 807-8555, Japan.
Abstract:
Twelve patients with cortical reflex myoclonus were electrophysiologically investigated. From the results of the recording of the C reflex during voluntary contraction, cortical reflex myoclonus was classified into three subtypes: type I; C reflex with recurrent C reflex (C'), type II; double C reflexes (C1, C2) and type III; C reflex with evident inhibition. The jerk-locked motor evoked potential (MEP) showed different mechanisms in the C' and C2 reflexes. The findings of cortical delay, facilitatory effect of peripheral stimulation on MEP and jerk-locked MEP indicate that both cortical reflex myoclonus and the silent period after the C reflex in patients with type III cortical reflex myoclonus might originate from a change of cortical excitability of the motor cortex.
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