Efficacy of nicergoline treatment in Parkinson's disease associated with dementia.

Parkinson's disease (PD) has a variable spectrum of cognitive impairment. However, there are no clear evident-based management guidelines for PD with dementia (PDD). Alternative treatments for PDD are therefore required. We conducted this longitudinal study to evaluate the efficacy of nicergoline in treating PDD by analyzing changes in regional cerebral blood flow (rCBF) and neuropsychological tests before and after nicergoline administration. A total of nine PDD patients who received nicergoline therapy (PDD + N) and 14 PD patients who did not receive nicergoline therapy (PDD - N) underwent single photon emission computed tomography (SPECT) and clinical assessments at baseline and 12-month follow-up visits. The PDD + N received nicergoline at 30 mg twice per day. Changes in rCBF were compared between the groups, and correlation analysis was performed to determine possible relationship between rCBF and clinical characteristics. There were no significant differences in rCBF between the two groups at baseline. Although changes in cognitive test scores and the motor severity scale were not significantly different between baseline and the 12-month follow-up within groups, rCBF was lower in both the temporal and inferior frontal restricted areas in the PDD - N group than the PDD + N at the 12-month follow-up visit. In conclusions, nicergoline appears to delay the speed of deterioration of cognitive function in patients with PDD based on our observation of decreased rCBF in the temporal regions and inferior frontal regions of PDD - N patients compared to PDD + N patients after 12-month of nicergoline therapy. Therefore, we cautiously suggest that nicergoline administration in PDD patients may slow progression of cognitive impairment in affected brain regions.