RT Journal Article SR Electronic T1 PET Measurement of Cardiac and Nigrostriatal Denervation in Parkinsonian Syndromes JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1769 OP 1777 VO 47 IS 11 A1 David M. Raffel A1 Robert A. Koeppe A1 Roderick Little A1 Chia-Ning Wang A1 Suyu Liu A1 Larry Junck A1 Mary Heumann A1 Sid Gilman YR 2006 UL http://jnm.snmjournals.org/content/47/11/1769.abstract AB Scintigraphic imaging with 123I-metaiodobenzylguanidine (123I-MIBG) has demonstrated extensive losses of cardiac sympathetic neurons in idiopathic Parkinson's disease (IPD). In contrast, normal cardiac innervation has been observed in 123I-MIBG studies of multiple-system atrophy (MSA) and progressive supranuclear palsy (PSP). Consequently, it has been hypothesized that cardiac denervation can be used to differentiate IPD from MSA and PSP. We sought to test this hypothesis by mapping the distribution of cardiac sympathetic neurons in patients with IPD, MSA, and PSP by using PET and 11C-meta-hydroxyephedrine (11C-HED). Also, the relationship between cardiac denervation and nigrostriatal denervation was investigated by measuring striatal presynaptic monoaminergic nerve density with PET and 11C-dihydrotetrabenazine (11C-DTBZ). Methods: 11C-HED and 11C-DTBZ scans were obtained for patients with IPD (n = 9), MSA (n = 10), and PSP (n = 8) and for age-matched control subjects (n = 10). Global and regional measurements of 11C-HED retention were obtained to assess the extent of cardiac sympathetic denervation. 11C-DTBZ binding was measured in the caudate nucleus, anterior putamen, and posterior putamen. Results: As expected, extensive cardiac denervation was observed in several of the patients with IPD. However, substantial cardiac denervation was also seen in some patients with MSA and PSP. 11C-DTBZ studies demonstrated striatal denervation in all patients with IPD and in most patients with MSA and PSP. No correlation was found between cardiac 11C-HED retention and striatal 11C-DTBZ binding. Conclusion: Cardiac sympathetic denervation was found to occur not only in IPD but also in other movement disorders, such as MSA and PSP. This finding implies that scintigraphic detection of cardiac sympathetic denervation cannot be used independently to discriminate IPD from other movement disorders, such as MSA and PSP. Cardiac sympathetic denervation was not correlated with striatal denervation, suggesting that the pathophysiologic processes underlying cardiac denervation and striatal denervation occur independently in patients with parkinsonian syndromes. These findings provide novel information about central and peripheral denervation in patients with neurodegenerative disorders.