Background: The reported prevalence of sleep apnoea following stroke varies between 44% and 72%, but its course and relations are unclear.
Aim: To determine the prevalence and course of sleep-disordered breathing in acute stroke in-patients, and its relation to age, stroke subtype, pre-stroke handicap and post-stroke outcome.
Design: Prospective uncontrolled observational study.
Methods: Paired respiratory sleep studies were performed at week 2 and week 6-9 following stroke. Pre- and post-stroke handicap (modified Rankin Score) and week 2 and week 6-9 disability (Barthel Score) and impairment (Scandinavian Neurological Stroke Score) were assessed. Pre-stroke sleepiness was determined by Epworth Score.
Results: There were 68 patients in the week 2 study, and 50 in the week 6-8 study. Mean week 2 Apnoea Hypopnoea Index (AHI) was 30; 64 patients (94%) had an AHI > or =10. Mean AHI was higher in subjects with lacunar vs. cortical strokes (44 vs. 28, p<0.05), in subjects aged > or =65 years (32 vs. 21, p<0.05) and in those with greater pre-stroke handicap (modified Rankin Score 2 vs. <2) (41 vs. 27, p<0.05). In 50 paired studies, mean AHI fell from 31 to 24 (p<0.01) and the proportion with AHI > or =10 fell from 96% to 72%. Pre-stroke sleepiness was associated with post-stroke neurological impairment (r=-0.325, p<0.05) and disability (r=-0.377, p<0.05).
Discussion: Sleep-disordered breathing improves in the first 6-9 weeks following stroke, but remains highly prevalent. Worse sleep-disordered breathing was observed following lacunar stroke, and in older subjects or those with pre-stroke handicap.