Impact of Cognitive Decline on Swallowing Function and Food Texture: A Retrospective Study Using VESS

Objective

Although cognitive decline is known to affect swallowing function, large-scale studies using videoendoscopic study of swallowing (VESS) remain limited. This study aimed to retrospectively analyze the relationship between cognitive function, swallowing function evaluated by VESS, and food texture.

Methods

A total of 487 patients (332 males, 156 females; mean age: 77 ± 12 years) were included. Cognitive function was assessed using the DASC-21* (Dementia Assessment Sheet for Community-based Integrated Care System-21 items) and classified into four groups: "no impairment," "mild," "moderate," and "severe." Swallowing function was evaluated using the Hyodo score** in the VESS. Food texture was categorized into five levels, including non-oral intake, based on a comprehensive evaluation of eating and swallowing functions.

To explore the relationship between cognitive function and dysphagia, Hyodo scores were compared between "no/mild cognitive impairment" and "moderate/severe cognitive impairment" groups. Additionally, food texture was analyzed in two groups based on Hyodo scores: ≤5 (anticipated oral intake of semi-solid food or more) and ≥6.

Results

Hyodo scores differed significantly between the "no/mild impairment" and "moderate/severe impairment" groups. For patients with Hyodo scores ≤5, food texture also showed significant differences between "no impairment" and "moderate impairment," as well as between "mild impairment" and "moderate impairment." However, for patients with Hyodo scores ≥6, no significant differences in food texture were observed between groups.

Discussion

Cognitive impairment influences swallowing function, but pharyngeal swallowing function remains relatively unaffected until cognitive decline progresses to a moderate level. In cases of mild pharyngeal swallowing dysfunction, cognitive impairment affects food texture selection, likely through its impact on the preparatory phase of swallowing. However, in moderate-to-severe swallowing dysfunction, food texture is predominantly determined by the severity of swallowing dysfunction itself, with less influence from cognitive impairment.

Conclusion

Cognitive decline minimally affects pharyngeal swallowing function until moderate impairment occurs. Nonetheless, even in cases with mild pharyngeal dysfunction, cognitive impairment can impact food texture selection through preparatory phase considerations.

*Awata S, et al. Geriatrics & Gerontology International 2016;16(Suppl-1): 123-131.

** Hyodo M, et al. Nihon Jibiinkoka Gakkai Kaiho 2010; 113: 670-678.