“…Parkinson's disease (PD) patients complain of sleep disorders more often than a normal population of the same age group; the reported prevalence being as high as 70% (Kales et al, 1971;Nausieda et al, 1984;Lees et al, 1988). The causes of sleep disorders are multifactorial: disturbances of sleeping regulation and architecture, drug-induced sleep disorders and impairment of motor function (April, 1966;Kales el al., 1971;Schneider et al, 1974;Moskovitz et al, 1978;Scharf et al, 1978;Laihinen et al, 1987;Factor et al, 1990). Sleep related respiratory disturbances such as central or obstructive sleep apneas effect sleep quality in PD (Guilleminault er al., 1977;McNicholas et al, 1983;Apps et al, 1985;Aloe et al, 1990).…”