Category: Parkinson's disease: Neuroimaging
Objective: This study aimed to evaluate 123I-metaiodobenzylguanidine (MIBG) uptake in the major salivary glands (MSG) in patients with rapid eye movement sleep behavior disorder (RBD) and to compare it between RBD and Parkinson’s disease (PD).
Background: RBD is a parasomnia considered to be a preclinical stage of synucleinopathies like PD. In RBD, peripheral lesions have been identified, probably suggesting the pathological progression from outside the brain.
Method: We recruited nine patients with RBD (polysomnography-confirmed RBD: 4 and RBD screening questionnaire for Japanese (RBDSQ-J)-based probable RBD: 5), 81 with PD and 25 non-parkinsonian controls in the present study. We analyzed MIBG uptake in the parotid glands, submandibular glands, and the heart, using a novel quantitative semi-automatic method both in the early and delayed phases. Then, we compared the parotid/mediastinum (P/M) ratio, the submandibular/mediastinum (S/M) ratio, and the heart/mediastinum (H/M) ratio among the three groups. We also evaluated correlations between MSG and the heart in RBD.
Results: Between RBD and controls, the early and delayed phases P/M and the early S/M were significantly reduced in RBD than in controls (early P/M: p = 0.002, delayed P/M: p = 0.033 and early S/M: p = 0.003). Cardiac MIBG uptake in RBD was significantly lower than controls (both early and delayed H/M: p < 0.001). By contrast, the early phase S/M in PD was significantly lower than RBD, but the others showed statistical equivalence between RBD and PD. Both MSG and the cardiac MIBG uptake in PD were significantly lower than controls. Furthermore, we found positive correlations between P/M and S/M but did not find correlations between MSG and the heart in RBD and PD.
Conclusion: Sympathetic denervation might also occur in the MSG in addition to the heart in RBD, probably reflecting the radiological peripheral lesions as a preclinical stage of synucleinopathies.
To cite this abstract in AMA style:
J. Ebina, S. Mizumura, M. Shibukawa, J. Nagasawa, T. Hirayama, N. Ishii, Y. Kobayashi, A. Inaba, S. Orimo, O. Kano. Comparison of MIBG Uptake in the Major Salivary Glands Between Rapid Eye Movement Sleep Behavior Disorder and Parkinson’s Disease [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/comparison-of-mibg-uptake-in-the-major-salivary-glands-between-rapid-eye-movement-sleep-behavior-disorder-and-parkinsons-disease/. Accessed November 20, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/comparison-of-mibg-uptake-in-the-major-salivary-glands-between-rapid-eye-movement-sleep-behavior-disorder-and-parkinsons-disease/