Analysis of the relationship between muscle sympathetic nerve activity and cardiac ¹²³I‐metaiodobenzylguanidine uptake in patients with Parkinson's disease

Abstract

To analyze the correlation between muscle sympathetic nerve activity (MSNA) and cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake in patients with Parkinson's disease (PD), we measured both parameters in 14 PD patients who were 51 to 82 years of age (mean, 63.1 +/- 8.7 years). The duration of PD was 2 to 26 years, and the disability level (modified Hoehn and Yahr stage) ranged from 2.0 to 4.0 (mean, 3.2 +/- 0.5). MSNA was recorded from the peroneal nerve fascicles using microneurographic methods, and then cardiac MIBG scintigraphy was performed within 1 month. We analyzed the correlation between the standardized MSNA, expressed as a percentage of the predicted value based on control subject data, and the heart-to-mediastinum ratio (H/M) or washout ratio (WR) from early and delayed MIBG images. The relationships between disease duration or disability and MSNA, the H/M ratio, or the WR were also analyzed. No significant correlations were found between MSNA and H/M ratio or WR. Although MSNA was inversely correlated with disease duration and with disability level, neither the H/M ratio nor the WR showed a significant correlation with disease duration or disability level. Because MSNA and MIBG abnormalities were not related, functional changes in addition to organic changes in cardiac sympathetic nerve endings may result in abnormal uptake of MIBG in Parkinson's disease. .

Blunted cardiovascular responses to exercise in Parkinson’s disease patients: role of the muscle metaboreflex

“…Nonetheless, the TPR response was significantly lower in patients with PD in both situations, which could possible indicate, assuming a normal neurovascular transduction, a blunted MSNA. Prior studies have shown that older men are highly reliant on sympathetic outflow for beat-to-beat regulation of BP (Vianna et al 2012), and patients with PD are known to exhibit an inverse relationship between MSNA and age (Shindo et al 2003(Shindo et al , 2005(Shindo et al , 2008. Accordingly, patients with PD have displayed lower MSNA responses to stressful situations (Shindo et al 2003(Shindo et al , 2008, a finding that could be demonstrated in our experiments by the lower increase in TPR.…”

“…Accordingly, patients with PD have displayed lower MSNA responses to stressful situations (Shindo et al 2003(Shindo et al , 2008, a finding that could be demonstrated in our experiments by the lower increase in TPR. Also, studies have shown that patients with PD present loss of sympathetic cardiac nerves (Goldstein et al 2005;Nakamura et al 2010;Shindo et al 2005), lower norepinephrine release (Goldstein et al 2003), and lower ␣-adrenergic responsiveness (Sharabi et al 2008). The current literature is devoid of morphological characteristics of skeletal muscle of patients with PD.…”

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

“…MIBG uptake reflects the function of cardiac sympathetic neurons. The reason why cardiac uptake of MIBG is decreased in PD has been thought to be that the postganglionic neurons of myocardial sympathetic nerves are easily impaired in this disorder [2][3][4]. Our data showed significant correlations between the % MABP reduction and H/M ratio on early and delayed images.…”

“…It presumed that there might be some differences between PD patients and controls with relation to activity levels during daytime and the frequency of arousal and micturition during nighttime from diary of ABPM examination and description. Previous reports showed that a lower nocturnal BP fall was frequent among patients with PD [1][2][3][4]12]. A commonly accepted explanation for the nocturnal BP decline is diminution of sympathetic nervous system activity paralleling the change in wakefulness.…”

“…Recent functional imaging studies using 123 I-MIBG cardiac scintigraphy have demonstrated myocardial postganglionic sympathetic nerve function in neurodegenerative disorders and diabetes mellitus [1][2][3][4]. In these studies, patients with idiopathic Parkinson's disease (PD) frequently had abnormal MIBG scintigraphic findings, and a relationship between MIBG findings and clinical features or disease specificity has been characterized in several previous studies [1][2][3][4].…”