Upper and Middle Thoracic Esophageal Dilation in patients with Spinal and Bulbar Muscular Atrophy

Objective Spinal and bulbar muscular atrophy (SBMA) causes oral and pharyngeal dysphagia; however, esophageal involvement remains unclear. This study aimed to clarify esophageal involvement in SBMA by using chest computed tomography (CT). Methods Patients with SBMA who visited our hospital between 2014 and 2025 and underwent chest CT were included. Male stroke patients served as controls. The maximum thoracic esophageal diameter was measured on chest CT in patients with SBMA and stroke. A videofluoroscopic swallowing study (VFSS) was performed in the SBMA group. Results Fifty-seven patients (12 with SBMA and 45 with stroke) were included in the study. The upper thoracic esophageal diameter was larger in the SBMA group (15.4 vs. 11.1 mm; p=0.035). In the middle segment, the diameter was larger in the SBMA group (13.1 vs. 5.1 mm; p=0.004). In the lower segment, the diameter tended to be larger in the SBMA group, but the difference was not statistically significant. Multiple regression analyses showed that age (B=0.13, 95% confidence interval [CI]=0.02-0.24; p=0.026) and SBMA (B=5.35, 95% CI 1.09-9.60; p=0.015) independently predicted upper thoracic esophageal dilation. SBMA was an independent predictor in the middle segment (B=5.11, 95% CI 1.28-8.94; p=0.01). VFSS was performed in 8 patients with SBMA. Esophageal residue after swallowing thickened liquid was observed in six patients. Conclusion SBMA was associated with upper and middle thoracic esophageal dilation on chest CT. Esophageal dysfunction warrants attention along with oral and pharyngeal dysphagia.