Obstructive Sleep Apnea and Wake-up Stroke – A 12 Months Prospective Longitudinal Study

Background: Wake-up stroke (WUS) are strokes that are noted upon awakening in patients previously going to bed in a normal state of health. The role of sleep abnormalities in WUS is uncertain. The objective was to determine clinical characteristics, respiratory abnormalities during sleep and outcomes in patients with WUS versus non-WUS. Methods: At baseline, patients with ischemic stroke were examined clinically and with a portable sleep recorder. Apnea-Hypopnea Index greater than or equal to 20 defined a cut-off severity index. At follow-up (3 and 12-months), patients were re-evaluated clinically and with questionnaires: Epworth Sleepiness Scale, Modified Rankin (MR) and Modified Barthel Index Results: Among all (N = 102, 64% male), hypertension (73%), Type 2 diabetes (29.4), heart disease (16.7%), physical inactivity (69.6%), smoking (32.4%) and alcohol consumption (17.6) were found. Apnea-Hypopnea Index (AHI) greater than 5 (92.9%), AHI greater than 15 (44.7%), AHI greater than or equal to 20 (35.3%) and AHI greater than 30 (11.8%) were registered. Cases with and without WUS did not differ regarding polygraphic findings. Long apneas (apnea duration > 20 s) was equally found in patients with WUS (23.1%) and non-WUS (23.7%). Type 2 diabetes mellitus (T2D) was independently associated with WUS (OR = 2.76; CI: 1.10-6.05; P = .03). Prospectively, symptom severity was not different between WUS and non-WUS. Overall, patients with OSA (IAH≥20) evolved with worse functional performance (MR, P = .02). Conclusions: Wake-up stroke occurred in approximately 1 of 3 of cases. Irrespective of WUS, half of the patients had moderate to severe sleep apnea; those with OSA (AHI≥ 20) evolved with worse functional performance after 1 year. WUS was associated with TDM reinforcing a relationship with cerebral small vessel disease.