Changes in systemic arterial pressure during sleep in Shy-Drager syndrome.

Polygraphic findings during spontaneous nocturnal sleep of 2 patients suffering from Shy-Drager syndrome are reported. In both patients, total sleep time was reduced--sleep latency and awakening periods during the night being increased. Considerable reductions of rapid eye movement (REM) stage and, in 1 patient, also of deep non-REM (NREM; stages 3-4) were found. No apneas were recorded. In normal subjects, systemic systolic and diastolic pressure decreases during all the sleep stages; in our patients, arterial pressure values rose progressively during NREM sleep stages and showed a further increase in REM sleep. In all the sleep stages, sudden phasic swings of systemic arterial pressure were observed.