Levodopa versus non-levodopa brain language fMRI in Parkinson’s disease

Objective: To identify the effect of levodopa in language areas inParkinson’s disease patients. Methods: We evaluated 50 patientswith mild to moderate Parkinson’s disease, age and gender pairedto 47 healthy volunteers. We selected two homogeneous groupsof 18 patients taking levodopa and 7 no levodopa patients. Thefunctional magnetic resonance imaging verbal fluency task, withlow and high cognitive demands, was performed at a 3T magneticresonance imaging equipment. Data was analyzed with XBAMsoftware for group maps and ANOVA comparison. Results: Patientswithout levodopa had more activation than the ones with levodopa inthe medial frontal and in the left frontal and parieto-occipital areas.The striatal activation in patients taking levodopa had similar resultof the activation detected in the healthy volunteer group. Parietooccipitalareas were less activated in the levodopa group than in theno levodopa one. Conclusion: Parkinson’s disease patients withoutlevodopa replacement, during a verbal fluency effort, had morediffuse and intense cerebral activation in left hemisphere, mainlyin the frontal and parieto-occipital areas. The striatal activation inverbal fluency of patients with levodopa intake was more similar tothe activation found in healthy volunteers. These initial evidencessuggested a role of levodopa inhibiting activation in parieto-occipitalcompensating areas.