Dysphagia in Amyotrophic Lateral Sclerosis: Relationships between disease progression and Fiberoptic Endoscopic Evaluation of Swallowing.

Objective: Our aim was to evaluate the relationship between the disease severity of Amyotrophic Lateral Sclerosis (ALS) and the following parameters of Fiberoptic Endoscopic Evaluation of Swallowing (FEES): premature spillage, post-swallowing residue and aspiration.

Methods: We studied 202 patients (95 women and 107 men) with ALS; of these, 136 had spinal and 66 had bulbar onset. They were analyzed according to the Amyotrophic Lateral Sclerosis Functioning Rating Scale (ALSFRS) and the b-ALSFRS subscale (bulbar scale). All subjects underwent FEES. Post-swallowing residue was classified into four classes (0-3); premature spillage and aspiration were considered either present or absent.

Results: Spearman's correlation test showed a highly significant correlation (p<0.0001) between the value of ALSFRS and b-ALSFRS and the FEES parameters as the following: disease severity and dysphagia severity are closely related, both in spinal and bulbar onset, no matter what bolus texture was used. Spearman's Rho was more significant for post-swallowing residue, ≤-0.500 with all three consistencies (p<0.0001) in spinal onset and -0.520 only with liquid bolus (p<0.0001) in bulbar onset. Independent T-Test revealed a significant difference (p<0.0001) between the mean ALSFRS and b-ALSFRS scores and the presence/absence of aspiration. For the premature spillage in spinal onset (ALSFRS), we found a statistically significant difference for all three bolus textures (p<0.0001). Analysis of variance for the post-swallowing residue in spinal onset (ALSFRS) revealed a statistically significant difference (p<0.0001) for most of the comparisons between groups for all three textures. For the premature spillage in bulbar onset (b-ALSFRS), we found a statistically significant difference for all three textures (p<0.0001). Analysis of variance for the post-swallowing residue in bulbar onset (b-ALSFRS) showed a statistically significant difference (p<0.0001) for most of the comparisons between groups for all three textures. Kruskal-Wallis test showed a highly significant association between the classes of severity in bulbar forms and all the FEES parameters, no matter what type of bolus was administered (p<0.0001), whereas a significant correlation in spinal forms only for post-swallowing residue with solid (p=0.026) and semisolid (p=0.031) boluses.

Conclusion: There is a highly significant relationship as the following between the FEES parameters and the disease severity assessed via ALSFRS and b-ALSFRS: classes of greater severity entail a greater deterioration of FEES parameters. FEES can be considered a good indicator of the dysphagia severity and a useful test for the follow-up of dysphagia in patients with ALS, whether of spinal or bulbar onset.