Sleep apnea and dysphagia in patients after a stroke recovering in convalescence rehabilitation.

Statement of problem: Sleep apnea is prevalent among patients after a stroke and can complicate recovery, particularly in those with dysphagia. While studies have investigated sleep apnea in patients after a stroke in acute-care settings, its prevalence and impact of those in convalescent rehabilitation remain largely unknown.

Purpose: The purpose of this clinical study was to investigate the prevalence and severity of sleep apnea among patients after a stroke in convalescent rehabilitation and to explore the relationship between the severity of sleep apnea and dysphagia.

Material and methods: In total, 196 patients after a stroke hospitalized in a rehabilitation hospital in Chiba Prefecture, Japan were enrolled in this study. The participants had suffered a stroke and had been admitted for post-stroke rehabilitation after being discharged from acute-care hospitals. An overnight sleep test was administered with WatchPAT, which measured the apnea-hypopnea index (AHI), minimum SpO₂ (MinSpO₂), and 3% oxygen desaturation index (ODI3%). Functional oral intake level was assessed with the Functional Oral Intake Scale (FOIS). Statistical analyses were conducted by using multiple regression followed by the 2-sample t test, Kruskal-Wallis tests, and the chi-squared test (α=.05).

Results: Among the initial 196 participants enrolled, 140 participants (78 men and 62 women; mean age, 73.3 ±12.4 years) underwent a sleep test, with only 91 completing it. Out of the 91 participants, 85 (93.4%) had sleep apnea, and the prevalence increased to 95.7% specifically among participants with dysphagia. Significant differences in Japan Coma Scale scores (P<.001) and modified Rankin Scale scores (P<.001) were observed between the tube-dependent (FOIS 1 to 3) and total oral diet (FOIS 4 to 7) groups. Multiple regression analysis revealed a significant association between AHI and BMI (P=.020), and AHI and FOIS (P=.007), adjusted for age, sex, and confounding factors.

Conclusions: This study revealed a high prevalence of sleep apnea among patients after a stroke in convalescent rehabilitation, as well as a significant correlation between the severity of sleep apnea and dysphagia. Clinicians should consider sleep apnea management as a critical component of post-stroke rehabilitation, given its potential for improving swallowing function.