title: EEG in phenylketonuria. Attempt to establish clinical importance of EEG changes.
abstract: To determine the importance of an abnormal EEG in phenylketonuria (PKU), we reviewed 137 EEGs from 48 patients with PKU. Patients were divided into three groups: group 1 (n = 14) had only normal EEGs, group 2 (n = 20) had only abnormal EEGs, and group 3 (n = 14) initially had normal EEGs that later became abnormal. The most common EEG abnormality was focal paroxysmal discharge. Patients in group 2 started treatment at a later age an had a greater frequency of seizures and mental retardation. Phenylalanine levels greater than 20 mg/dL were more often associated with abnormal EEGs. Older patients were more likely to have abnormal EEGs; 78% of the 41 patients who had EEGs at age 6 or older had abnormal records, whereas only 15% of the 26 patients who had EEGs before the age of 6 had abnormal records. Conventionally treated patients with classic PKU and normal EEGs in infancy may have abnormal EEGs when retested later even though they remain on a restricted diet. Although not usually associated with clinical deterioration, abnormal EEGs may unveil the presence of CNS dysfunction even when a child is in satisfactory clinical condition.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D005071:Evoked Potentials; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000175:diagnosis; D010649:Phenylalanine / Q000097:blood; D010661:Phenylketonurias / Q000175:diagnosis* / Q000178:diet therapy; D012640:Seizures / Q000175:diagnosis
chemical_list: D010649:Phenylalanine