Levodopa improves spatial contrast sensitivity in Parkinson's disease
J. T. Hutton, J. L. Morris and J. W. Elias
Parkinson's Disease Research Center, St Mary of the Plains Hospital, Lubbock, TX 79410.
OBJECTIVE--To study the effect of levodopa on the visual contrast
sensitivity of patients with Parkinson's disease. DESIGN--Contrast
sensitivity of patients was measured before and after levodopa
administration. Patient contrast sensitivity was compared with that of
normal controls by repeated-measures analyses of variance.
SETTING--Parkinson's disease research center associated with private
neurology practice. PATIENTS--Fifteen patients with idiopathic Parkinson's
disease (eight men, seven women; mean age, 71.8 years) and 22 normal
controls (10 men, 12 women; mean age, 68.0 years) volunteered for the
study. INTERVENTION--Levodopa/carbidopa (Sinemet). MAIN OUTCOME
MEASURE--Change in contrast sensitivity of parkinsonian patients.
RESULTS--Following levodopa treatment, the contrast sensitivity of
parkinsonian patients improved significantly at the three lowest spatial
frequencies tested (0.4, 1, and 2 cycles per degree). CONCLUSIONS--Levodopa
improves low-frequency contrast sensitivity in parkinsonian patients.
Initially deficient contrast sensitivity in such patients may be restored
to near normal levels by levodopa therapy.