[Rett's syndrome: description of a case with abnormal respiratory pattern].

Rett' syndrome is a progressive disorder that occurs in females and is characterized by autistic behavior, dementia, ataxia, loss of purposeful use of the hands, and seizures. Patients with Rett' syndrome have been observed to have stereotyped hand movements (hand-washing) and to exhibit intermittent hyperventilation. To characterize more precisely the respiratory pattern associated with this disorder, SAO2 and pH studies were made during sleep and wakefulness in a girl with this syndrome. These studies showed abnormal respiratory pattern during wakefulness characterized by hyperventilation periods (SAO2 98%, alkalosis) and ipo-apnea (SAO2 80%); during the sleep, ventilation became regular (SAO2 94-96%). The occurrence of disorganized breathing and compensatory hyperpnea during wakefulness with regular, continuous breathing during sleep suggests an altered or impaired voluntary/behavioral respiratory control system.