Characteristics and Risk Factors of Aspiration in Lateral Medullary Infarction

Abstract

Objective: To evaluate the characteristics of dysphagia and identify the risk factors of bolus aspiration in patientspresenting with pure lateral medullary infarction (LMI). Methods: Between January 2014 and January 2019, 51 post-stroke patients with LMI who underwent a videofluoroscopicswallowing study (VFSS) were enrolled retrospectively, and their medical records and brain magnetic resonanceimaging results were reviewed. The VFSS results were evaluated to analyze the swallowing function using thepenetration-aspiration scale, functional dysphagia scale, and imaging analysis software. Results: Bolus aspiration was detected in 21 patients (41.2%). The common abnormal VFSS findings were residue invalleculae (74.5%), delayed triggering of pharyngeal swallow (72.5%), residue in pyriform sinuses (62.7%), delayed pharyngealtransit time (56.9%), reduced laryngeal elevation (51.0%), and coating of the pharyngeal wall (49.0%). Theincidence of aspiration was significantly higher in the typical lesions (including the diagonal band-shaped lesions)and the large type lesions extending ventrally or dorsally, as compared to other lesion types (P＜0.05). Logistic regressionanalyses revealed that the residue in pyriform sinuses is a significant independent risk factor of aspirationin the puree trial, and prolonged pharyngeal delay time (PDT) and residue in valleculae are significant risk factorsin the thin liquid trial (P＜0.05). Conclusion: Considering all clinical factors, lesion locations, and swallowing processes, results of the current studyindicate that residue in pyriform sinuses is an independent risk factor of aspiration in the swallowing puree technique,whereas prolonged PDT and residue in valleculae are independent risk factors of aspiration in the swallowingliquid technique.