[Rett's syndrome: study of 15 cases].

A multicentric study of 15 cases of Rett syndrome selected with the diagnostic criteria according HAG-BERG et al: female sex, normal pre and perinatal period, normal psychomotor development through the first months of life, early dementia between 1-3 years of age with autistic behaviour, loss of acquired purposeful hand skill, "washing hands" stereotypies, normal head circumference at birth with later deceleration of head growth and truncal ataxia with gait apraxia. Waking EEG showed unspecific abnormalities while sleep recording demonstrated extremely frequent multifocal spike and sharp waves mainly over the rolandic region and generalized, and also pseudo-periodic suppression of background activity. In 3 cases the EMG showed a peripheral axonal neuropathy. Only in one case we found hyperammonemia. Karyotypic studies performed in 12 cases demonstrated non specific fragile sites. CT scan was normal in almost all cases. The QD was extremely low.