Correlation of Dysphagia with Functional Decline in Neurodegenerative Disease – A Review

Abstract

Hypothesis: The functional decline noted over time in patients with neuromuscular diseases is associated with increasing risk of dysphagia and aspiration. Study design: Systematic literature review. Methods: A Pub Med search to identify all of the literature addressing neuromuscular disease progression and correlation with dysphagia was performed in the English literature from 1/1/2000 through 4/1/2015. Studies with outcomes measures for both functional decline and dysphagia or aspiration were included, whereas stroke and head injury were excluded. Results: Of the 309 articles identified in the search, 13 discussing Parkinson's disease [PD] and 5 on the topic of Amyotrophic Lateral Sclerosis [ALS] met the criteria. No papers on the subjects of Multiple Sclerosis [MS] or Huntington's disease [HD] were identified. Articles were stratified by level of evidence using the criteria of Sackett et al. [1], noting instrument selection for disease state and dysphagia, self-reported vs. observed, outcome and limitations. There were 8 true longitudinal studies, and the other 10 stratified patients by duration or disease severity. Overall, the studies support increased dysphagia or swallowing related quality of life decline in patients with advanced PD and ALS. However, most studies are limited by 1) the cross-sectional nature instead of true longitudinal design, 2) self-reported instruments and 3) infrequent mention of aspiration risk. Conclusion: Progressive dysphagia and aspiration risk is weakly demonstrated with advancing PD and ALS. Although these are similar known risks with MS and HD, there are only anecdotal reports. A systematic approach at screening these patients for dysphagia is warranted.