Longitudinal analysis of progression of dysphagia in amyotrophic lateral sclerosis

Abstract

Objective: To investigate the progression of dysphagia in amyotrophic lateral sclerosis (ALS) using videofluoroscopy (VF), according to two different scales: the duration following bulbar symptom onset, and the ALS severity scale (ALSSS). Methods: Seventy-two VF examinations, on 50 ALS patients, were performed at various time points, and the change in VF findings in the oral and pharyngeal phases was analyzed over time following bulbar symptom onset. The change according to advancement of the ALS severity scale was also assessed. Results: Delayed bolus transport from the oral cavity to the pharynx, and bolus stasis at the pyriform sinus (PS), were seen in about half of the patients with no bulbar complaints. In contrast, upper esophageal sphincter (UES) opening was relatively well maintained in the late stage of dysphagia. The other parameters, such as bolus holding in the oral cavity, constriction of the pharynx, and elevation of the larynx, became worse over time following bulbar symptom onset. These parameters on VF examination also became worse as the ALSSS advanced; however, even patients in the group with normal eating habits showed disturbed bolus transport from the mouth to the pharynx, weak constriction of the pharynx, and bolus stasis at the PS. Generally, dysfunction had progressed dramatically, in most of the parameters, in the patients that required modification of food; however, UES opening and elevation of the larynx were relatively well maintained in advanced-ALSSS patients. Conclusion: In this study, we clearly show the progression pattern of dysphagia in ALS, and we also emphasize that VF is a useful tool to follow swallowing function in ALS patients. From our results, it would be useful to perform VF by 6 months following bulbar symptom onset, because VF can contribute to rehabilitation or appropriate diet modification; and later, around 1 year following bulbar symptom onset, VF should again be performed, since ALS patients show wide-ranging nutrition intake patterns, and they need assessment to introduce intervention, such as tube feeding, according to their varying status of dysphagia, around at this time point.