Association of Sleep Disordered Breathing with Wake-Up Acute Ischemic Stroke: A Full Polysomnographic Study

Abstract

Study Objectives: Sleep disordered breathing (SDB) is a frequent comorbidity in stroke patients. SDB is one of the independent risk factors for ischemic stroke. Conversely, stroke may contribute to SDB onset or aggravate premorbid SDB. Multiple mechanisms underlying SDB might be responsible for the development of stroke. The aim of this study was to compare polysomnographic, clinical, and laboratory characteristics of wake-up (WUS) and non-wake-up acute ischemic strokes (NWUS). Methods: We prospectively enrolled 88 patients with acute ischemic stroke. Clinical characteristics of the population were recorded on admission, and blood samples were obtained in the fasting condition following morning. SDB was assessed using standard overnight polysomnography in the acute phase of the stroke. Results: WUS were present in 16 patients (18.2%), and NWUS in 72 patients (81.8%). In WUS compared to NWUS, we observed significantly higher values of apnea-hypopnea index (24.8 vs. I NTRO DUCTI O NA recent population-based study has shown that wake-up strokes (WUS) comprise 14% of all ischemic strokes. The same study concludes, that WUS do not differ from non-wake up strokes (NWUS) in clinical features, risk factors, or outcome.1 There is a diurnal variation in the onset of stroke. Sleep tends to promote ischemic stroke, and there is a higher frequency of strokes occurring in the morning.2,3 Sleep disordered breathing (SDB) is present in up to 72% of stroke patients and is one of the independent risk factors for stroke. 4,5 However, stroke may also aggravate premorbid SDB or even contribute to SDB onset. 6 Multiple mechanisms might link SDB with the onset of cerebral ischemia during the sleep, including coagulation changes, hemodynamic changes, blood pressure (BP) surges, inflammatory overactivity, increased arterial stiffness, increased sympathetic tone, paradoxical embolization, or the development of cardiac arrhythmias. 7-11Currently, WUS patients are excluded from revascularization therapy; therefore, a thorough search for predictors and risk factors of WUS is desirable. The aim of this study was to compare polysomnographic, clinical, and laboratory characteristics of WUS and NWUS with mild-to-moderate severity. SCIENTIFIC INVESTIGATIONS Association of Sleep M ETHO DSThe study population consists of patients hospitalized in the stroke unit of the 1 st Department of Neurology, Comenius University Bratislava from January 2011 to December 2014 with the BRIEF SUMMARY Current Knowledge/Study Rationale: Currently, wake-up stroke patients are excluded from revascularization therapy, so a precise search for predictors and risk factors of wake-up strokes is desirable. The aim of this study was to compare polysomnographic, clinical, and laboratory characteristics of wake-up strokes and non-wake-up strokes with mild-to-moderate severity. Study Impact: We emphasize the importance of significantly higher frequency of moderate-to-severe sleep apnea syndrome among the wake-up stroke population, as this population is indicated for positive...

Wake-up stroke is not associated with sleep-disordered breathing in women

“…The respective study populations could also differ, although our study sample showed similar age and baseline stroke severity to those reported in previous studies that did demonstrate an association between WUS and AHI. [4][5][6] Our negative finding is consistent with the results found in women in the only prior study that performed a sex-specific analysis. 6 Importantly, the inclusion of strokes with onset during non-nocturnal sleep (naps) added almost 5% to the estimate of WUS in this study.…”

“…The estimate provided by this and some studies 4,6 suggests that WUS is higher (;one-third) than other studies suggest. 3,5 Our result is also in keeping with estimates from the large International Stroke Trial. 11 In this study, participants with WUS had a milder presentation (e.g., more presented fully conscious, and more had lacunar syndromes) than non-WUS participants.…”

“…1 Sleep-disordered breathing (SDB), found in the majority of patients poststroke, 2 has been hypothesized to be causally linked to WUS. 3 Three small studies (n = 71-88 with physiologic SDB assessment) that excluded severe stroke patients have suggested a higher prevalence of SDB in those with WUS than those without, 4,5 although this finding was limited to men in one of the studies. 6 Overall, the relationship between SDB and WUS has not been well-characterized and data have not been population-based.…”

Increased Risk of Ischemic Stroke during Sleep in Apneic Patients

“… 13 14 15 Lower blood pressure was suggested as a risk factor for WUS, 11 but this finding has not been replicated in other studies. Four 12 15 16 17 of six 11 12 13 15 16 17 studies that assessed OSA as a stroke risk factor found that habitual snoring or a higher apnea-hypopnea index in poststroke polysomnography (PSG) was more frequent among WUS patients ( Supplementary Table 1 in the online-only Data Supplement). However, poststroke PSG cannot be used to diagnose preexisting OSA due to the high prevalence of new-onset OSA following acute stroke.…”

Clinical Characteristics and Functional Outcomes of Wake-Up Stroke in the Chinese Population

“…We prospectively evaluated consecutive patients with acute stroke (≤3 days after onset) who were admitted to the First Affiliated Hospital of Chongqing Medical University between April 2017 and December 2017. WUS was defined as the occurrence of new symptoms suggestive of stroke detected upon waking from sleep (regardless of the time of the day), and non-WUS was defined as the occurrence of stroke symptoms during the awake state [21]. Among the 612 patients with acute stroke, we excluded patients with the following criteria: delayed admission more than 3 days after onset (n = 3), stroke mimics (n = 34), other diseases with stroke-like attacks (n = 3), loss to follow-up (n = 17), transient ischemic attacks (defined as stroke symptoms that last <24 h, n = 51), daytime-unwitnessed stroke (n = 29), and hemorrhagic stroke (n = 2).…”