Polysomnographic recordings of respiratory disturbances in Rett syndrome.

Polygraphic recordings in the awake state and during sleep were performed in two girls with Rett syndrome, aged 9 y and 17 y, in order to characterize the clinically manifest breathing disorder of these patients. Primary hyperventilation was detected, leading to hypocapnia and compensatory apnoea. Hypoxaemia occurred as the consequence of prolonged apnoea. In the younger patient these disturbances were observed only in the awake state, whereas in the older patient they were found in the awake state and during sleep.