Neurological findings in early treated phenylketonuria.

[classical phenylketonuria]

Twenty early treated , normal intelligent patients (IQ : mean 101 .4 , SD 10 .0 ; age : mean 10 .11 , SD 1 .3 years ) with classical phenylketonuria and 20 age-, sex- and IQ-matched healthy controls were investigated for neurological outcome , especially with regard to fine motor ability using the motor performance task ("Motorische Leistungsserie "). No pathological findings were seen on clinical neurological examination . The patient group had significantly poorer results in a concentration task (Test-d-2 ) as well as in some subtests of the motor performance task . Patients had difficulties in tasks which needed speed and precision of arm-hand -finger movements . High serum phenylalanine concentrations were significantly correlated with these deficiencies in fine motor ability . Our data demonstrated mild neurological impairment even in early and relatively strictly treated patients with phenylketonuria .