Twenty-one patients affected by extrapyramidal disorders were polygraphically recorded during spontaneous nocturnal sleep for two consecutive nights to assess their sleep and movement patterns. The patients (pts) sample included: Gilles de La Tourette syndrome (TS, nine pts), neuroacanthocytosis (NA, six pts) and Hungtington's chorea (HC, six pts). Sleep recording included C3/A2, 01/A2, ROC/LOC, submental EMG, EKG, nasal airflow thoracoabdominal respirogram, bilateral anterior tibialis and other EMGs, in relation to the individual distribution of the abnormal movements. According to our observations, abnormal movements always decreased but never ceased completely during sleep. Sleep efficiency (SE) was nearly always poor with a high percentage of wakefulness after sleep onset (WASO) and increased number of arousals. REM sleep was often reduced and in some cases (3 TS pts) incompletely defined as far as its microstructural aspects. Slow wave sleep (SWS) was reduced in HC, normal in NA, and increased in all TS patients with the exception of the two adult subjects more severely affected, while the percentage of stage 2 was not affected. Spindling was increased in NA, HC and in the two most severely affected adult TS patients.