Levodopa and psychometric test performance in parkinsonism-5 years later.

Forty parkinsonian patients on levodopa therapy for a mean of 4 years and 10 months were given a battery of psychometric tests to assess memory cognition, and perception. Three equated control groups consisting of (1) parkinsonian patients not on levodopa, (2) patients on short-term levodopa, a mean of 1 year and 1 month, and (3) spouses, were administered a similar battery. The experimental group performed better than the nonlevodopa and the short-term groups on two subtests of intellectual functioning, but did less well on two tests of recent memory. All three parkinsonian groups consistently did significantly worse than spouses. When sex, age, and other relevant variables are equated, longer term levodopa therapy does not significantly after the overall pattern of psychometrically tested functions generally reported in parkinsonian patients.