Photomyoclonic response of epileltic and non-epileptic subjects during wakefulness, sleep and arousal

Abstract

1. 1. The clinical photomyoclonic response (PMR) of eleven photosensitive epileptic patients and two non-epileptic subjects was studied by polygraphic EEG and ultraviolet apparatus recording of single responses and by computer summation. The responses spread after single light flashes over the deltoid, biceps, forearm flexors, quadriceps and gastrocnemius muscles with latencies of about: 61, 64, 65, 83 and 95 msec respectively. Agonists and antagonists contracted almost simultaneously. 2. 2. These latencies are virtually identical to those of the sub-clinical physiological reflex described by Bickford as the “photo-motor response”. The PMR is considered as an enhancement of it. 3. 3. In NREM sleep, following arousal from NREM sleep and during REM sleep, the PMR and the photoconvulsive response were diminished. Following arousal from REM sleep they were less diminished and quickly became those of wakefulness. 4. 4. In patients with petit mal absences and petit mal myoclonus, arousal from NREM sleep, unlike that from REM sleep, provoked prolonged myoclonus associated with EEG poly-spike and wave discharges while the PMR and PCR remained suppressed.