Fifteen right-handed patients with mild PD [Hoehn – Yahr I–III], treated with L dopa, aged 36 to 80 years, without signs of dementia, were examined by a short test battery, including simple reaction time [SRT], continuous performance test [CPT] and switching attention test in visual and symbolic modali- ties [SATv, SATs]. All patients were assessed in an optimal clinical status, UPDRS motor scores were obtained. The results were compared with twenty-four age-matched controls. Mean SRT and CPT were prolonged in patients as compared with the control group, while reaction times [Rt] in SATv and SATs did not differ. UPDRS scores correlated significantly with Rt in SATv [p<0.001], CPT [p<0.01]. SRT [p<0.01] and the number of errors in CPT [p<0.02]. In 2 patients was found an increase of Rt under all conditions without any relation to the UPDRS score and age. Rt in SATv, CPT, SRT and number of errors in CPT reflect the motor impairment in PD and may be useful for the complementary monitoring of the clinical status in PD.

        Key words: Parkinson’s disease, reaction time, continuous performance test, switching attention test, dementia