REVIEW OF NEUROPSYCHOLOGICAL FUNCTIONING IN TREATED PHENYLKETONURIA -AN INFORMATION-PROCESSING APPROACH

Phenylketonuria is no longer associated with mental retardation and ot her devastating neurological effects. Nonetheless, learning disabiliti es and IQ loss are common, even in early-treated individuals. Until re cently, IQ was used as the sole measure of mental functioning in this population. As specific academic deficits were recognized and as a gre ater variety of tests became available, evaluation of children with ph enylketonuria has included neuropsychological testing. A review of the 21 published reports highlights the areas of consensus and the need f or additional well designed studies in the future. Problem solving, pa rticularly abstract reasoning and executive functions, appears to be i mpaired in children with phenylketonuria. Reaction time, or speed of m ental processing, appears to be the other important area affected in P KU. An information processing model is presented as a paradigm for fur ther research and development of remedial strategies for children with phenylketonuria.