[EEG-results in early-treated children with phenylketonuria 4 through 10 years under treatment (author's transl)].

EEG-results in 21 children with Phenylketonuria (PKU), put on a diet at least since their 3rd month of life, now aged 4 through 10 years, with normal psychomotor development, lacking abnormal neurological signs, are compared with the results in 796 healthy children of the same age. Visual evaluation and frequency analysis of the background activity of the EEGs reveal no differences between children with PKU and controls. Generally, there is no close correlation between mean plasma levels of phenylalanine (phe-means) during treatment, and the composition of the EEG when combined age groups are compared. But a trend can be demonstrated: In the small group of 8 years old children phe-means up to 6 mg-% can be associated with a faster (alpha), and phe-means above 6 mg-% with a slower (theta) background activity. The frequency of metabolic derailment (single phe-values above 10 mg-%) does not correlate with the EEG. Focal and generalized hypersynchronous activity (HSA) is observed significantly more often even in early treated, normally developing children with PKU. In children aged 4--8 years, HSA is associated with a high proportion of slow waves compared with those who do not display HSA. In children 9 and 10 years old, however, no such differences can be seen. It is hypothesised that even early treated children with PKU, in their first years show a retardation in the development of their background activity but catch up by 9--10 years. It still remains uncertain whether further age-appropiate development of the EEG can be observed after liberating or discontinuing the dietary regimen at this age.