Deficits in selective and sustained attention processes in early treated children with phenylketonuria--result of impaired frontal lobe functions?

Eur J Pediatr. 1996 Mar;155(3):200-4. doi: 10.1007/BF01953938.


Twenty normally intelligent children with early treated phenylketonuria (PKU) (IQ: mean = 101.4, SD = 10.0; age: mean = 10 years 11 months, SD = 1.3 years) and 20 healthy controls, matched for age, sex and IQ, were assessed for their selective (Stroop Task) and sustained attention (Test-d-2). Using positron emission tomography an activation of the frontal lobe during the Stroop task had previously been demonstrated. In addition to the Stroop Task and the Test-d-2, a short-term memory test as a "non-frontal-lobe-function-task" was administered to all subjects. Group comparisons demonstrated that PKU children had specific deficits in selective and sustained attention, which were significantly correlated with the concurrent serum phenylalanine concentration.

Conclusion: The results give evidence that even dietary treated children with PKU were suffering from impaired attentional control mechanisms in spite of a normal IQ. The deficits might be the result of impaired frontal lobe functions.

MeSH terms

  • Adolescent
  • Attention / physiology*
  • Attention Deficit Disorder with Hyperactivity / diagnosis
  • Attention Deficit Disorder with Hyperactivity / physiopathology*
  • Child
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Frontal Lobe / physiopathology*
  • Humans
  • Infant
  • Infant, Newborn
  • Intelligence / physiology*
  • Male
  • Mental Recall / physiology
  • Neuropsychological Tests
  • Phenylalanine / blood
  • Phenylketonurias / diagnosis
  • Phenylketonurias / diet therapy*
  • Phenylketonurias / physiopathology


  • Phenylalanine