[Diminution of hand writing area and D2-dopamine receptor blockade. Results from treatment with typical and atypical neuroleptics].

Beside the typical extrapyramidal motor symptoms such as rigidity, tremor, and dyskinesia, a reduction in handwriting area may occur under neuroleptic therapy. To date, the nature of the relationship between a reduction in handwriting area and striatal D2 dopamine receptor occupancy has remained unclear, and it is not known whether such a reduction also occurs under treatment with atypical neuroleptic drugs. In 23 schizophrenic patients treated with haloperidol, haloperidol decanoate, risperidone, and clozapine, the handwriting are was examined using a planimetric computer program. 123I-iodobenzamide (IBZM) single photon emission tomography (SPET) was used to measure the D2 dopamine receptor occupancy. A statistically significant correlation was found between a reduction in handwriting area and D2 dopamine receptor occupancy (r = 0.86; P < 0.0001). The curve derived from the plotted data resulted in a hyperbolic function. The regression was present regardless of whether the patients were treated with typical or atypical neuroleptic drugs.