Short-term effect of amantadine sulphate on motor performance and reactiontime in patients with idiopathic Parkinson's disease

In thirty patients with idiopathic Parkinson's disease (PD) we examined in a prospectively designed study the effect on motor performance and cognitiv e functions of amantadine sulphate, applied intravenously over a period of 14 days. Prior to the introduction of amantadine and post infusionem the mo tor function was measured by the Unified Parkinson Disease Rating Scale (UP DRS) and the Motor Performance Test Series (MPS); the simple and the choice reaction time were assessed using the Vienna Reaction Unit (VRU). The prim ary endpoint of efficacy was the change in the UPDRS part III (motor examin ation) after 14 days of amantadine sulphate administration compared with ba seline. Secondary end-points were changes in the variables of the MPS and V RU at the end of administration interval compared with baseline. Overall, after 14 days of intravenous amantadine administration (200 mg/day ), a significant improvement was obtained in motor performance with respect to the semiquantitative motor scores of the UPDRS (p = 0.002) and the quan titative motor variables in the pertinent subtests of the MPS, reflecting p recision and speed of arm-hand movement as well as manual and finger dexter ity, for the right (p < 0.01) and the left hand (p < 0.05). However, all pa tients being viewed collectively, it was observed that there was a widely d iffering time delay of efficient motor response to amantadine from 4 to 9 d ays between individuals, whilst the quality of motor response remained stab le for the follow-up period. Although simple reaction time showed no signif icant improvement, choice reaction time shortened significantly in less aff ected PD patients staging Hoehn and Yahr I to III (p < 0.05). We conclude that apart from efficacy on motor performance, amantadine sulph ate - applied intravenously - has a positive effect on cognitive functions, particularly in less affected PD patients.