NR AKTO
AU Shibasaki,H.; Neshige,R.
TI Photic cortical reflex myoclonus
QU Annals of Neurology 1987 Aug; 22(2): 252-7
PT journal article
AB Three patients with flash-evoked myoclonus were studied electrophysiologically. Myoclonic jerks were elicited at a fixed latency after the application of photic stimuli and were always preceded at a fixed time interval by extremely enhanced cortical evoked potentials. The enhanced electroencephalographic (EEG) responses to flash were widely distributed over the scalp and were maximal at the central region; the occipital response preceded the frontocentral response by 3.4 to 5.1 msec. The interval from the frontocentral EEG response to the flash-evoked myoclonus was similar to that from the giant somatosensory evoked potential to the electrically evoked myoclonus. Investigation of recovery of evoked cortical responses and of myoclonic jerks showed a period of extremely enhanced excitability of both central and peripheral phenomena following stimulus. All of these findings suggest a cortical reflex mechanism. The role of the occipital cortex in the pathogenesis of photic cortical reflex myoclonus remains to be elucidated.
MH Adult; Aged; Cerebral Cortex/*physiology; Creutzfeldt-Jakob Syndrome/complications; Electroencephalography; Electromyography; Epilepsies, Myoclonic/complications; Evoked Potentials, Somatosensory; Female; Human; Light/*adverse effects; Male; Middle Age; Myoclonus/complications/*etiology/physiopathology; *Reflex; Support, Non-U.S. Gov't
AD Department of Internal Medicine, Saga Medical School, Japan.
SP englisch
PO USA