BRAIN MAGNETIC-RESONANCE-IMAGING IN CHILDREN WITH OPTIMALLY CONTROLLED HYPERPHENYLALANINEMIA

This study was undertaken to investigate whether the white-matter chan ges on MRI and the EEG abnormalities detectable in treated adolescents and adults with hyperphenylalaninaemia (HPA) can be detected in young er children on an optimally controlled diet. The study included 17 chi ldren, 7-12 years of age, with HPA. The MRI of five healthy children w ere included in the blind evaluation of the MR images. According to mu tation genotype and dietary tolerance of phenylalanine, 9 patients hav e severe HPA and 8 have moderate HPA, all requiring dietary treatment. Mild white-matter hyperintensity was detected in 1 of the 5 healthy c hildren and in 10 of 17 patients. EEG was abnormal in 2 patients. This group of children was compared with a previously reported group of ad olescents with HPA who had been treated according to the same dietary regimen. MRI changes and EEG abnormalities were significantly less fre quent in the group of children than in the group of adolescents. It is suggested that the more frequent MRI changes and EEG abnormalities se en in adolescents are related to the fact that a relaxation of the die tary treatment after the age of 8 years is often accepted.