Impaired cardiovascular autonomic function in Parkinson's disease with visual hallucinations.

We assessed the relations of visual hallucinations (VH) to cardiovascular autonomic dysfunction in patients with Parkinson's disease (PD). The subjects were 37 patients without VH (VH(-)) and 31 with VH (VH(+)). Autonomic function was evaluated on the basis of cardiac 123-radioiodinated metaiodobenzylguanidine (123I-MIBG) uptake and hemodynamic testing with Valsalva maneuver. Systolic blood pressure (SBP) and plasma norepinephrine concentrations (NE) were measured by tilt-table testing. 123I-MIBG uptake was lower in VH(+) than VH(-). Hemodynamic studies showed that VH(-) had only cardiac sympathetic and parasympathetic dysfunction, while VH(+) additionally had reduced vasomotor sympathetic functions. The fall in SBP during tilt-table testing was greater in VH(+) than VH(-). NE and its difference in the supine and upright positions were decreased in VH(+). We conclude that cardiac and vasomotor sympathetic dysfunction is more severe in VH(+) than in VH(-). Severe dysfunction in PD with VH is probably attributed to Lewy-body lesions or neuronal loss in sympathetic ganglia, the central autonomic system, or both.