The impact of cognitive decline in amyotrophic lateral sclerosis on swallowing. A scoping review

Purpose: Impaired swallowing is a serious symptom of amyotrophic lateral sclerosis (ALS) impacting on health and wellbeing. Little is known about how cognitive impairment in amyotrophic lateral sclerosis impacts on oropharyngeal swallowing. A scoping review was undertaken to explore how cognitive impairment impacts on a person living with ALS’s (plwALS) ability to understand and manage oropharyngeal swallowing function. Method: Subject headings and keywords were searched across MEDLINE, SCOPUS, CINAHL, PsychINFO, Emcare and Google Scholar in May 2019. Articles containing information on amyotrophic lateral sclerosis and cognition and swallowing were reviewed. A secondary search was conducted in July 2020 with broadened search terms. Result: The primary search identified 1055 articles, and 47 were included for full-text review. Of these, no articles directly met the inclusion criteria of both cognitive impairment and swallowing. The secondary search with broadened terms identified an additional 762 studies, and 9 were included for full-text review, but none met the inclusion criteria. Consequently, thematic analysis was completed on articles from the full-text review to identify themes that related to both cognition and swallowing. The themes identified were: (i) early specialised multidisciplinary management of ALS achieves better outcomes; (ii) cognitive impairment impacts on management; and (iii) impaired swallowing occurs in nearly all people living with ALS and is a serious symptom of the disease. Conclusion: The interaction between cognitive impairment and oropharyngeal swallowing function in ALS has not been investigated. This is important, as cognitive impairment impacts insight and decision-making and may have implications for oropharyngeal swallowing management.