[Sleep in chronic chorea patients after therapy with sodium valproate]

In previous researches spontaneous nocturnal sleep in chronic chorea showed short total sleep time, prolonged sleep latency, several awakenings, reduction of REM sleep time, decrease in slow waves sleep, strong increase in sleep spindles. Some of these alterations improved after therapy with lithium, haloperidol and lithium, pimozide. Since the concentration of GABA has been found to be reduced in patients with Huntington's chorea, we studied the effect of sodium valproate, a drug that enhances GABA inhibition in cerebral cortex, on nocturnal sleep of six patients with chronic chorea, aged 35 to 60 years (mean 47,3). Nocturnal polygraphic records (EEG, EOG, EMG of chin muscles) were carried out after two consecutive adjustative nights, both before therapy and after sixty days of treatment with sodium valproate (800-2000 mg four times a day, orally). Moreover, chorea, finger dexterity and gait were each rated once a week by three members of the research team and by one independent observer, using a five points rating scale from 0 (normal) to 4 (very severely abnormal). Before therapy the sleep parameters were in accordance with our previous results in chronic choreic patients. After two months therapy we observed a statistically significant (P less than 0.05) reduction of awakenings and of wake time. Sodium valproate produced no objective change in any of the parameters of motor function studied. If singularly examined, however, a reduction of chorea was obtained only in a patient, whose favourable response to therapy was also demonstrated by the normalization of other sleep parameters. These data stress the importance of sleep study in extrapyramidal disorders and suggest a different involvement of GABA-mediated transmission in various patients with chronic chorea.