Association of visual hallucinations with reduction of MIBG cardiac uptake in Parkinson's disease

Background: Postganglionic cardiac sympathetic denervation is evident in patients with Parkinson's disease (PD) and iodine-123 metaiodobenzylguanidine (I-123-MIBG) cardiac scintigraphy has proven to be a useful tool for diagnosis of PD. Objective: To elucidate the factors associated with severity of cardiac sympathetic nerve dysfunction in PD patients. Methods: We investigated 95 PD patients hospitalized in the Department of Neurology at Tottori University Hospital. I-123-MIBG cardiac scintigraphy was performed on each patient and the early and delayed heart to mediastinum (H/M) ratios and washout rate (WR) of I-123- MIBG cardiac scintigraphy were calculated. Independent predictive variables for parameters of I-123-MIBG cardiac scintigraphy were analyzed by multivariate regression analysis. Results: Multivariate regression analysis revealed that the presence of visual hallucinations (VH) and the patient's age at the time of evaluation independently predicted the early or delayed H/M ratio. Analysis of covariance, adjusted for the age of the patients as covariates, revealed that the early and delayed H/M ratios of PD patients with VH but no dementia, as well as PD patients with dementia were significantly lower than the ratios in PD patients with no VH or dementia. Conclusion: Cardiac sympathetic dysfunction may be associated with the presence of VH in PD patients. (C) 2007 Elsevier B.V. All rights reserved.