Basal ganglia N-acetylaspartate correlates with the performance in the procedural task 'Tower of Hanoi' of neuroleptic-naive schizophrenic patients.

We tested the hypothesis that basal ganglia dysfunction may be related to procedural learning impairment in schizophrenia. We determined the N-acetylaspartate/choline (NAA/Cho) ratio in the left striatal area in 11 young first-episode antipsychotic-naive patients and matched controls. Procedural learning was assessed by the four-disk version of the Tower of Hanoi. Analysis of variance showed that the number of moves and the execution time had a significant group effect (P=0.02, P<0.0001, respectively). Correlation analysis between procedural learning and the NAA/Cho ratio showed a negative significant correlation only in patients, measured by both time (P=0.006) and by moves (P=0.001). In summary, we found that schizophrenic patients have impaired procedural learning, and that this impairment is related to basal ganglia metabolism.