[Neurological status and psychomotor development of children with phenylketonuria treated early].

Low phenylalanine diet treatment in children with phenylketonuria (PKU) started sufficiently early prevents mental retardation. But the question whether the treatment prevents all c n s damage is still open. This problem was evaluated on the basis of longitudinal neurological and psychological studies of 118 PKU children in whom treatment was started before the 6-th week of life. As a comparative group 90 children with untreated or late treated PKU were investigated. A detailed analysis of the results was carried out investigating each case in relation to the precision of dietary restrictions and the duration of treatment. The incidence and type of abnormal findings were compared with the abnormalities found in children with untreated or late treated PKU and with the incidence in the total child population. In 78 children (66,1%) there were no abnormalities in the neurological status and mental development was normal except for some retardation in the visual-motor maturation. In 35 children (29,7%) signs of hyperkinetic syndrome were present in 5 (4,2%) there was both mental retardation and signs of hyperkinetic syndrome. In the comparative group all 90 children had severe neurological abnormalities and mental retardation. The obtained results confirm that the essential effect of the diet on the development of PKU patients is during the first year of life. In order to obtain optimal results however, it is necessary to continue the diet for a sufficiently long period. But in spite of following the prescribed treatment in PKU children it is not always possible to prevent minimal c n s damage.