CHANGES OF VAGUS NERVE CROSS-SECTIONAL AREA AS A DISEASE-SPECIFIC IMAGING BIOMARKER IN EARLY PARKINSON'S DISEASE PATIENTS

초록

Background: Several studies have reported atrophy of the vagus nerve (VN) in patients with parkinsonism, but most reports have been conducted on advanced patients group. This study aimed to compare VN size in patients with Parkinson’s disease (PD) according to the disease stages and nondegenerative parkinsonian (non-PD) patients using high-resolution ultrasonography (HRUS). Methods: We evaluated patients presenting with parkinsonism at our department. Experienced neurologist who blinded to clinical information conducted HRUS examinations to measure the cross-sectional area (CSA) of the VN at the level of carotid artery bifurcation. Results: We assessed total 57 consecutive patients (44 with PD and 13 with non-PD (scans without evidence of dopaminergic deficits)). Among PD group, 36 were in early-stage [Hoehn &Yahr stage (HY) ≤ 2.5], and 8 were in advanced-stage (HY ≥ 3). The mean CSAs of right VN were significantly smaller in the PD patients compared to non-PD patients (PD 1.73 mm vs. non-PD 2.00 mm, P = 0.049). Right VN atrophy was more distinct in advanced-stage PD group than in the early-stage PD group (late PD 1.54 mm vs. early PD 1.77 mm, P = 0.035). The CSA of the left VN tended to be smaller in the PD group and advanced-stage PD group compared to the non-PD group and early-stage PD group, respectively (late PD 1.31 mm, early PD 1.35 mm, and non-PD 1.47 mm). Conclusions: This study suggests that the VN size measured by HRUS could be a useful supplementary method in the diagnosis and evaluation of PD. VN size in PD might be a disease-specific marker rather than progression marker in this study. Additional validation studies on large samples are further needed.