Systemic blood pressure profile correlates with cardiac ¹²³I-MIBG uptake in patients with Parkinson's disease

To examine the correlation between the systemic blood pressure profile and cardiac ¹²³I-metaiodobenzylguanidine (MIBG) uptake in patients with Parkinson's disease (PD), we monitored circadian blood pressure patterns of 37 PD patients of 49 to 85 years of age (mean, 71.8 ± 8.4 years) using a portable blood pressure monitoring device. The duration of PD was 0.5 to 15 years, and the disability level (modified Hoehn and Yahr stage) ranged from 1.0 to 4.0 (mean, 2.7 ± 0.7). There were 37 age- and sex-matched control subjects. Cardiac MIBG scintigraphy was performed for the 37 PD patients. Based on the nocturnal fall in mean arterial blood pressure (MABP), we classified patients into extreme dippers (nocturnal reduction of MABP > 20%), dippers (> 10% but < 20%), nondippers (< 10% but > 0%), and inverted dippers (< 0%). Average 24-hour MABP values revealed reduced BP variability in PD patients. The percentage nocturnal fall in MABP was significantly different between PD patients and control subjects (p < 0.05). Significant correlations were found between % MABP reduction and the heart-to-mediastinum (H/M) ratio on early and delayed images (p < 0.01). The UPDR motor score, early and delay H/M ratios were also significantly different between patients who were and were not dippers (p < 0.05). The present results reported for the first time a significant correlation between the systemic blood pressure profile and cardiac ¹²³I-MIBG uptake in patients with PD. The degeneration between the brainstem and the postganglionic neurons of myocardial sympathetic nerves may progress in parallel in patients with PD.