Polygraphic Study of Dyssynergia Cerebellaris myoclonica (Ramsay-Hunt Syndrome) and of the Intention Myoclonus (Lance-Adams Syndrome) During Sleep

Abstract

In 10 subjects with Ramsay-Hunt (RH) syndrome and epilepsy, and in one case of Lance-Adams (LA) syndrome, 21 polygraphic sleep records were made. In the cases of RH syndrome the main findings were as follows: (a) Cyclic organization of sleep. The cyclic organization of sleep was quite well preserved in all cases and all the sleep stages were represented with percentages within normal ranges. Sleep pattern. In the majority of the cases the identification of the different sleep stages was particularly difficult, often because of the rarity of the spindles, K-complexes and vertex sharp waves. Modifications of the epileptic discharges during sleep. During wakefulness the abnormalities were characterized by brief (0.5–2 sec) bursts of generalized spike and wave discharges at 4–5 cps, usually of low voltage. During sleep two types of epileptic discharges were observed: the first consisted of generalized bursts of spike and wave discharges similar to those observed during wakefulness; these discharges were always present during slow sleep but less frequent than during wakefulness; in three cases they persisted during REM sleep. The second type of abnormality consisted of spikes or multiple spikes, isolated or in long-lasting discharges up to 20 sec of duration, focalized or maximal over the vertex and central regions. These spikes observed in 7 patients, occurred in all stages of sleep and were particularly evident during REM sleep. Ictal electroclinical seizures of a clonic type, sometimes of long duration (up to 20 min) occurred during slow sleep awakening the subjects. In the LA syndrome the most important finding was the apparition during sleep, and particularly during REM sleep, of focal spikes over the central and midline regions, similar to those observed in RH syndrome.