Myoclonic tremulous movements in multiple system atrophy are a form of cortical myoclonus.
We prospectively studied the clinical and electrophysiological features of myoclonic tremulous movements in patients with multiple system atrophy (MSA). Among 42 consecutive patients, 12 MSA-p (parkinsonian type) and 3 MSA-c (cerebellar type) patients showed small-amplitude myoclonic movements. These movements occurred in the distal part of the arms and fingers, particularly in posture or during voluntary movements. We conducted detailed electrophysiological studies in 11 patients. Electromyographic recordings showed irregular bursts of brief duration often synchronously involving the antagonistic muscles. Somatosensory evoked responses were slightly enlarged in some patients. Long-latency reflexes were enhanced in 7 patients. A jerk-locked averaging technique revealed premyoclonic cortical potentials in 9 patients. These findings suggest that small-amplitude myoclonic movements in MSA are a form of cortical myoclonus.
Okuma
Yasuyuki
Y
Department of Neurology, Juntendo University Izu-Nagaoka Hospital, Shizuoka, Japan.|Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
Fujishima
Kenji
K
Department of Neurology, Juntendo University Izu-Nagaoka Hospital, Shizuoka, Japan.|Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
Miwa
Hideto
H
Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
Mori
Hideo
H
Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
Mizuno
Yoshikuni
Y
Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
D000368:Aged; D002531:Cerebellum / Q000473:pathology; D003342:Corpus Striatum / Q000473:pathology / Q000503:physiopathology; D004569:Electroencephalography; D004576:Electromyography / Q000295:instrumentation; D004831:Epilepsies, Myoclonic / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008475:Median Nerve / Q000502:physiology; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000150:complications* / Q000473:pathology*; D018482:Muscle, Skeletal / Q000503:physiopathology; D009410:Nerve Degeneration / Q000473:pathology; D011149:Pons / Q000473:pathology / Q000503:physiopathology; D011446:Prospective Studies; D011699:Putamen / Q000473:pathology / Q000503:physiopathology; D013003:Somatosensory Cortex / Q000473:pathology* / Q000503:physiopathology*; D013378:Substantia Nigra / Q000473:pathology / Q000503:physiopathology