Postganglionic Sudomotor Dysfunction and Brain Glucose Hypometabolism in Patients with Multiple System Atrophy

Article type: Research Article

Authors: Kim, Seung Woo^{a; 1} | Chung, Seok Jong^{a; b; 1} | Lee, Sangwon^c | Oh, KyeongTaek^d | Yoo, Sun Kook^d | Lee, Phil Hyu^a | Kim, Seung Min^{a; b} | Shin, Ha Young^a | Yun, Mijin^{c; *}

Affiliations: [a] Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea | [b] Department of Neurology, Yongin Severance Hospital, Yonsei University Health System, Yongin, South Korea | [c] Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul, South Korea | [d] Department of Medical Engineering, Yonsei University College of Medicine, Seoul, South Korea

Correspondence: [*] Correspondence to: Mijin Yun, MD, PhD, Professor, Department of Nuclear Medicine, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea. Tel.: +82 2 2123 5851; Fax.: +82 2 365 5882; E-mail: yunmijin@yuhs.ac.

Note: [1] These authors contributed equally to this work.

Abstract: Background:Sudomotor dysfunction is common in patients with multiple system atrophy (MSA). Postganglionic sudomotor dysfunction in MSA, which can be assessed using quantitative sudomotor axon reflex testing (QSART), results from the degeneration of preganglionic sympathetic neurons and direct loss of postganglionic fibers. Objective:We investigate whether abnormal QSART responses in patients with MSA are associated with disease severity. Methods:In this retrospective study, patients with probable MSA who underwent both 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) and autonomic function tests were included. Autonomic function test results were integrated divided into three sub-scores, including sudomotor, cardiovagal, and adrenergic sub-scores. The sudomotor sub-score represented postganglionic sudomotor function. Unified Multiple System Atrophy Rating Scale (UMSARS) Part I, Part II, and sum of Part I and II scores (Part I + II) to reflect disease severity and 18F-FDG-PET/CT results were collected. Results: Of 74 patients with MSA, 62.2%demonstrated abnormal QSART results. The UMSARS Part I + II score was significantly higher in the abnormal QSART group than in the normal QSART group (p = 0.037). In the regression analysis, both UMSARS Part I (β= 1.185, p = 0.013) and Part II (β= 1.266, p = 0.021) scores were significantly associated with the sudomotor sub-score. On 18F-FDG-PET/CT, the abnormal QSART group exhibited more severely decreased metabolic activity in the cerebellum and basal ganglia in patients with MSA-P and MSA-C, respectively. The sudomotor sub-score was significantly associated with regional metabolism in these areas. Conclusion:Patients with MSA and postganglionic sudomotor dysfunction may have worse disease severity and greater neuropathological burden than those without.

Keywords: Multiple system atrophy, sudomotor dysfunction, autonomic dysfunction, brain metabolism.

DOI: 10.3233/JPD-202524

Journal: Journal of Parkinson's Disease, vol. 11, no. 3, pp. 1247-1256, 2021