TY - JOUR T1 - Cardiac and Extracardiac Sympathetic Denervation in Parkinson’s Disease with Orthostatic Hypotension and in Pure Autonomic Failure JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1775 LP - 1781 VL - 46 IS - 11 AU - Dnyanesh N. Tipre AU - David S. Goldstein Y1 - 2005/11/01 UR - http://jnm.snmjournals.org/content/46/11/1775.abstract N2 - The uptake of 6-18F-fluorodopamine by cardiac noradrenergic nerves enables visualization of the sympathetic innervation of the left ventricular myocardium by PET. Patients with Parkinson’s disease (PD) and orthostatic hypotension (OH) (PD+OH) or with pure autonomic failure (PAF) have markedly decreased myocardial 6-18F-fluorodopamine–derived radioactivity, consistent with cardiac sympathetic denervation, a phenomenon that neurochemical, neuropharmacologic, and, most recently, postmortem neuropathologic studies have confirmed. In this study, we examined whether 6-18F-fluorodopamine can visualize sympathetic innervation in extracardiac organs and, if so, whether patients with PD+OH or PAF have neuroimaging evidence of extracardiac noradrenergic denervation. Methods: To validate the method, healthy volunteers underwent 6-18F-fluorodopamine scanning of the head, thorax, and abdomen, with or without treatment with desipramine to block sympathoneural uptake of catecholamines. 13N-Ammonia scanning was used to address possible group differences in 6-18F-fluorodopamine delivery by blood perfusion. Results: Desipramine treatment was associated with decreased 6-18F-fluorodopamine–derived radioactivity in the heart, renal cortex, and thyroid gland but not in the liver, spleen, renal pelvis, or salivary glands. Both the PD+OH group and the PAF group had decreased 6-18F-fluorodopamine–derived radioactivity in the heart (P < 0.0001) and renal cortex (P = 0.02 and P = 0.005, respectively). The PD+OH group also had decreased radioactivity in the thyroid gland (P = 0.01). Neither group had decreased radioactivity in the other organs, after correction for 13N-ammonia–derived radioactivity. Conclusion: 6-18F-Fluorodopamine scanning visualizes sympathetic innervation in the heart, renal cortex, and thyroid gland. Both PD+OH and PAF involve decreased noradrenergic innervation that is most prominent in the heart but is also detectable in extracardiac organs. ER -