[Clinical and neurophysiological aspects of severe forms of autism in children].

The aim of the study was to elucidate fundamentals for the phenomenon of universality of childhood autism by comparison of clinical and neurophysiological features of its severest forms--children endogenous autism (CEA) and Rett's syndrome (RS). Each group included 20 patients. Both groups were similar by age-at-disease-onset, clinical appearances during the disease course and dynamics of psychopathological syndromes. The theta-rhythm is common for CEA and RS at the disease stage with marked signs of disease acuity, autism, regress and, therefore, may be regarded as a marker of severity and development delay. The universality of autism phenomenon in its severe forms was confirmed both at the clinical and neurophysiological levels.