123I-metaiodobenzylguanidine scintigraphy in Parkinson's disease and related disorders.
Autonomic dysfunction is common in Lewy body disorders (Parkinson's disease, Dementia with Lewy Bodies, Pure Autonomic Failure, and REM sleep disorder). The loss of post-ganglionic myocardial sympathetic nerve fibers is a prominent feature of autonomic dysfunction in such disorders. (123)I-metaiodobenzylguanidine (MIBG) scintigraphy that visualizes catecholaminergic terminals in vivo is a biomarker used to detect cardiac sympathetic degeneration. Abnormal MIBG uptake has been consistently reported in Lewy body disorders. Some studies agree in the notion that increasing bradykinesia is related with an incremental cardiac sympathetic denervation, whereas tremor is not closely linked to cardiac denervation. "Atypical" parkinsonian syndromes, including Multiple System Atrophy, Progressive Supranuclear Palsy, and others, show modest reductions of cardial MIBG uptake. MIBG scintigraphy is moderately sensitive and specific in differentiating Parkinson's disease from such syndromes. Conversely, its sensitivity and specificity might be better in cognitively impaired patients, helping differential diagnosis between Dementia with Lewy Bodies, and Alzheimer disease. Confounding factors (comorbidities, comedications) should be carefully controlled before analyzing MIBG scintigraphy.
Rascol
Olivier
O
INSERM CIC-P302 and UMR-825, Department of Clinical Pharmacology, Faculté de Médecine, CHU and University UPS of Toulouse, Toulouse, France. rascol@cict.fr
Schelosky
Ludwig
L
D019797:3-Iodobenzylguanidine; D001342:Autonomic Nervous System Diseases / Q000000981:diagnostic imaging / Q000209:etiology; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D020961:Lewy Body Disease / Q000150:complications / Q000000981:diagnostic imaging; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals
D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine