Clinical measures associated with aspiration risk in multiple system atrophy: a cross-sectional study.

Introduction: Identifying clinical measures associated with aspiration risk is crucial for guiding clinical decisions in patients with multiple system atrophy (MSA). We investigated whether basic clinical measures-including the Barthel index (BI), Unified MSA Rating Scale (UMSARS), and dopamine transporter single-photon emission computed tomography imaging (DaT imaging)-are associated with aspiration risk in patients with MSA. Methods: This cross-sectional, single-center study analyzed patients with MSA who underwent videofluoroscopic swallowing examinations (VF) and DaT imaging within 12 months of each other. Clinical measures were assessed within 3 months of VF. Patients were categorized into aspiration and non-aspiration groups based on VF findings. Multivariable modified Poisson regression and receiver operating characteristic (ROC) analyses were performed to explore the associations between clinical measures and aspiration, and their discriminative ability. Results: Among 105 patients with MSA (58 females; median age: 63 years [range: 43-87 years]), 28 (26.7 %) showed aspiration on VF. The aspiration group showed significantly lower BI and higher UMSARS scores than the non-aspiration group. In multivariable regression analyses, BI was consistently and significantly associated with aspiration across all models. ROC analysis demonstrated moderate discriminative ability both BI (AUC 0.77, 95 %CI 0.66-0.87) and UMSARS (AUC 0.73, 95 %CI 0.63-0.83) for aspiration, with overlapping confidence intervals. The association was particularly notable for the parkinsonian MSA subtype. Conclusion: The BI shows potential as a clinical marker of aspiration risk in MSA, particularly in the parkinsonian subtype, which may help guide the timing of swallowing assessments even in the absence of overt dysphagia symptoms.