Magnetoencephalographic analysis of cortical myoclonic jerks.
We studied the pre-myoclonus spike using magnetoencephalography in patients with cortical myoclonus (6 with cortical reflex myoclonus and one with epilepsia partialis continua). The spike was estimated as a single current dipole on the pre-central gyrus in one patient with epilepsia partialis continua. In contrast, it was estimated as a single dipole on the post-central gyrus in 5 of 6 patients with cortical reflex myoclonus, and as two dipoles on the pre- and post-central gyrus in the remaining patient. We conclude that there are 3 physiological types of cortical myoclonus: (1) abnormal discharges in the motor cortex produce the myoclonus; (2) the source of the myoclonus is mainly the sensory cortex; (3) both the motor and sensory cortices play important roles in the production of myoclonus.
Uesaka
Y
Y
Department of Neurology, School of Medicine, University of Tokyo, Japan.
Terao
Y
Y
Ugawa
Y
Y
Yumoto
M
M
Hanajima
R
R
Kanazawa
I
I
D004831:Epilepsies, Myoclonic / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D009044:Motor Cortex / Q000473:pathology / Q000503:physiopathology*