Some periodic phenomena arising during drowsiness and sleep in man

Abstract

In the course of numerous polygraphic recordings made on normal subjects and patients with sleep disturbances (Pickwickian syndrome, primary alveolar hypoventilation, restless legs syndrome and nocturnal myoclonus) we observed several vegetative and somatic phenomena which tended to oscillate or repeat themselves periodically every 20–30 sec during sleep, and especially during light sleep. The functional oscillations of this kind could involve the systemic arterial pressure, the pulmonary arterial pressure, cardiac rate, arteriolar tone, breathing, peripheral motoneurone excitability and the level of consciousness, both individually and simultaneously. It has been known for some time that systemic arterial pressure can present periodic oscillations at about every 30 sec (Meyer waves), especially in emergency situations; it has also been demonstrated experimentally that Mayer waves can be associated with periodic breathing and with cyclical oscillations of reticular tone, of pupil diameter and of the excitability of spinal motoneurones. During sleep, the physiological or pathophysiological situations which are the basis of these oscillatory phenomena could be represented by variations in pH, PCO 2, and PO 2 consequent on arterial hypotension or alveolar hypoventilation.