Motor excitability after the C reflex in cortical reflex myoclonus.
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.
Uozumi
Takenori
T
Department of Neurology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan, 807-8555, Japan.
Takechi
Utako
U
Yoshinaga
Kouichiro
K
Tsuji
Sadatoshi
S
D000328:Adult; D000368:Aged; D002648:Child; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009207:Myoclonus / Q000503:physiopathology*; D010525:Peripheral Nerves / Q000503:physiopathology; D012018:Reflex / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation