Characteristics of Dysphagia Based on the Type of ALS in Korean Patients Evaluated Using Videofluoroscopic Study: A Retrospective Analysis

Dysphagia is one of the main serious issues for amyotrophic lateral sclerosis (ALS) patients because of causing malnutrition and aspiration pneumonia. Early detection and management of dysphagia are essential for the long-term survival. In this study, videofluoroscopic swallowing study (VFSS) results of bulbar and spinal onset ALS patients were compared. VFSS results and revised ALS Functional Rating Scale (ALSFRS-R) score were also analyzed to assess the correlation between dysphagia and functional status of patients. ALS patients with swallowing difficulties who underwent VFSS were recruited retrospectively. Two oral, seven pharyngeal, and two esophageal components of VFSS were evaluated. An ALSRFRS-R bulbar subtype score < 9 was used to divide the groups with severe bulbar symptoms. Total 109 Korean ALS patients (39 bulbar vs 70 spinal) were included. Bulbar ALS patients exhibited a significantly longer oral transit time (OTT) then spinal ALS patients, especially in severe bulbar patients with low ALSRFRS-R bulbar subscale. In bulbar ALS patients, penetration (thick liquid), aspiration, OTT, and Penetration-Aspiration Scale (PAS) were significantly correlated with ALSFRS-R bulbar subscale score. However, in spinal ALS patients, only OTT (thin liquid) and aspiration (thick liquid) were significantly correlated with ALSFRS-R bulbar subscale score. Bulbar ALS patients demonstrated significantly longer OTT than spinal ALS patients, and ALSFRS-R bulbar subscale score also correlated well with bulbar ALS patients. Therefore, high vigilance and aggressive treatment for dysphagia especially in bulbar ALS patients rather than spinal ALS patients are mandatory.