Reduced cardiac 123I-MIBG uptake reflects cardiac sympathetic dysfunction in Lewy body disease

To examine the relation between the results of cardiac (123)I-meta-iodobenzylguanidine (MIBG) scintigraphy and cardiovascular autonomic function in Lewy body disease (LBD). The subjects were 66 patients with LBD, 44 of whom had Parkinson disease (PD), 10 PD with dementia (PDD), and 12 dementia with Lewy bodies (DLB); 20 age-matched healthy subjects were studied as controls. Cardiovascular autonomic function was evaluated on the basis of cardiac (123)I-MIBG uptake, cardiovascular autonomic response on the Valsalva maneuver (VM), and systolic blood pressure (SBP) response on head-up tilt table (HUT) testing. Patients with LBD had reduced cardiac (123)I-MIBG uptake, cardiovascular autonomic response on the VM, and SBP response on HUT testing as compared with controls. Cardiac (123)I-MIBG uptake and cardiovascular autonomic function in PDD and DLB were severely impaired as compared with those in PD. Cardiac (123)I-MIBG uptake in LDB was not significantly related to vasomotor sympathetic function, baroreceptor reflex gain, cardiac parasympathetic function, or the changes in SBP on HUT testing. Cardiac (123)I-MIBG uptake was, however, significantly related to the blood pressure overshoot in phase IV of the VM. Cardiac (123)I-meta-iodobenzylguanidine uptake clinically reflects cardiac sympathetic dysfunction in Lewy body disease.