123I-MIBG cardiac scintigraphy provides clues to the underlying neurodegenerative disorder in idiopathic REM sleep behavior disorder.
OBJECTIVE
RBD is considered to be a manifestation of an evolving synucleinopathy, such as Parkinson disease (PD), dementia of Lewy bodies (DLB), and multiple system atrophy (MSA). We tested whether the degree of accumulation of cardiac 123I-MIBG scintigraphy can distinguish the clinical syndromes associated with Lewy body-related disease from the syndrome of PSP (a tauopathy) and MSA.


METHODS
Cross-sectional.


METHODS
University-based sleep disorders laboratory.


METHODS
Subjects comprised 95 patients (31, idiopathic RBD; 26, PD; 10, MSA; 6, DLB; 13, progressive supranuclear palsy [PSP]) and 9 control subjects.


METHODS
To compare tracer uptake of cardiac 123I-MIBG between idiopathic RBD, PD, MSA, DLB, and PSP and control subjects.


RESULTS
Cardiac 123I-MIBG accumulation was evaluated by the heart/mediastinum (H/M) ratio. Mean value of the H/M ratio (early, delayed) was significantly reduced in patients with idiopathic RBD compared to MSA patients, PSP patients, control subjects (P < 0.001 in each group) and PD patients in early images (P < 0.05). There was a correlation between the H/M ratio and disease duration in the idiopathic RBD group. ROC analysis revealed that an H/M cut-off value of 1.9 was useful for differentiating RBD from MSA and PSP as well as distinguishing control subjects from those with RBD in both early and delayed images.


CONCLUSIONS
Cardiac 123I-MIBG findings are similar among idiopathic RBD and the syndromes of PD and DLB, but differ from those of PSP and MSA.
Miyamoto
Tomoyuki
T
Department of Neurology, Center of Sleep Medicine, Dokkyo Medical University School of Medicine, Tochigi, Japan. miyatomo@dokkyomed.ac.jp
Miyamoto
Masayuki
M
Suzuki
Keisuke
K
Nishibayashi
Momoka
M
Iwanami
Masaoki
M
Hirata
Koichi
K
D019797:3-Iodobenzylguanidine / Q000378:metabolism; D000368:Aged; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D020961:Lewy Body Disease / Q000000981:diagnostic imaging; D008297:Male; D008482:Mediastinum / Q000000981:diagnostic imaging; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging*; D010300:Parkinson Disease / Q000000981:diagnostic imaging; D017286:Polysomnography; D020187:REM Sleep Behavior Disorder / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D013494:Supranuclear Palsy, Progressive / Q000000981:diagnostic imaging
D019797:3-Iodobenzylguanidine