Colour vision abnormalities and movement time in Parkinson's disease

Visual system dysfunction has been reported in Parkinson's disease CPD). Th e objective of the present study was to evaluate a putative association of distorted colour vision and delayed initiation and execution of movement in PD. We performed the Farnsworth-Munsell 100-hue test and estimated the tot al error score in 30 previously untreated parkinsonian patients and 30 age- and sex-matched controls. We then determined slowness in motor readiness a nd motor programming in the parkinsonian subjects on the same day. Subjects were asked to press a start button and release it after the randomized app earance of a visual stimulus and to move their right index finger to a reac tion button as quickly as possible. Reaction time was considered as elapsed time between onset of the stimulus light and release of the start button, movement time was the time period between release of the start button and t he pressing of the reaction button. Significant differences appeared betwee n parkinsonian patients' and controls' reaction times (P = 0.007), movement time (P = 0.001) and total error score (P = 2.23E-08). A significant relat ion (Spearman R = 0.473, P = 0.008) was found between movement time and tot al error score, but not between reaction time and total error score (Spearm an R = 0.259, P = 0.166). We conclude, that visual dysfunction and executio n of movement are more influenced by altered dopaminergic neurotransmission in PD in comparison to the initiation of movement. fur J Neurol 6:711-715 (C) 1999 Lippincott Williams & Wilkins.