Effect of sleep-disordered breathing on recovery in patients with “wake-up” stroke

Background. Wake-up stroke (WUS) is often combined with sleep-disordered breathing and may potentially have a more unfavorable course. Objective — to evaluate the association between the time of stroke onset and the pattern of sleep-disordered breathing, as well as the effect of wake-up stroke on stroke recovery and stroke severity in patients with ischemic stroke. Design and methods. We included patients 18–85 years old with acute ischemic stroke admitted within 24 hours of symptom onset to the neurological resuscitation unit, and performed polygraphy within the first day of hospitalization to assess the parameters and severity of sleep-disordered breathing. In 2018–2023, 2122 patients were screened, polygraphy was performed in 639 patients, and data from 292 patients were included in the final analysis. Stroke severity was assessed using the NIHSS scale, stroke type was determined using the TOAST classification. WUS was considered when symptoms were detected upon awakening. Functional status was assessed by the Barthel index, and rehabilitation outcomes by the modified Rankin scale. The cumulative end point included death from any cause, new nonfatal myocardial infarction, new nonfatal stroke/transient ischemic attack, emergency revascularization, or emergency hospitalization due to exacerbation of cardiovascular disease. Results. WUS was detected in 101 patients (34,6 %). The WUS group had more frequent diabetes mellitus and higher NIHSS (p = 0,021) and Barthel index (p = 0,026) at discharge, less frequent thrombolytic therapy and emergency endovascular procedures (p = 0,007) which in most cases was associated with hospitalization in time beyond the therapeutic window (p < 0,001). Endpoints were reached in 21,6 % with a median follow-up of 209 days. No significant differences were found in the main indices of sleep-disordered breathing in groups of different severity and pathogenetic type of stroke. The most significant factors related to Barthel index were stroke severity at discharge (p < 0,001) and age (p < 0,001). Stroke severity at discharge was most influenced by thrombolytic therapy (p = 0,006) and stroke severity on admission (p < 0,001). Conclusions. Our study did not show the previously described higher incidence of sleep-disordered breathing in WUS. The best outcomes were in subjects who received reperfusion therapy. Patients with WUS should be hospitalized in a hospital where reperfusion therapy is available. Lower Barthel index values at discharge of patients with WUS may characterize their lower rehabilitation potential.