Circadian Variation in Acute Ischemic Stroke

Abstract

Background and Purpose-We investigated circadian rhythm in ischemic stroke onset and its subtypes, differentiating between first-ever stroke and recurrent stroke. Methods-A consecutive series of 1223 patients with ischemic stroke was admitted at 2 reference hospitals; the time of onset of symptoms was obtained, differentiating between onset while asleep and awake. We compared circadian rhythm between stroke types and between first-ever and recurrent stroke. Results-The onset time was known in 914 patients; 25.6% experienced onset on awakening [higher incidence in thrombotic and lacunar stroke (28.9% and 28.4%, respectively) than in embolic stroke (18.8%)]. For all stroke subtypes, there was a significant diurnal variation, with a morning peak between 6 AM and noon; after redistributing the hour of onset of patients awakening with stroke, the morning peak was minimal in all types of stroke. There were no differences in circadian rhythm between patients with first-ever and recurrent stroke. Conclusions-Only hospitalized patients were studied. There is a circadian rhythm in all types of stroke, with higher frequency during the day and lower frequency in the last hours in the evening. The highest incidence in the early hours of the morning can be overestimated, due to patients who awaken with stroke. There is no difference in circadian rhythm between first-ever stroke and recurrent stroke. (Stroke. 1998;29:1873-1875.)

Wake-up Stroke and Stroke within the Therapeutic Window for Thrombolysis Have Similar Clinical Severity, Imaging Characteristics, and Outcome

“…Similar to several ongoing therapeutic trials for WUS, we used the time since symptom recognition to select a subgroup of patients with WUS comparable with patients with STW. Studies suggest that WUS occurs predominantly in the early hours of the morning 1,8 ; therefore, the more suitable time point for defining WUS onset and for defining a therapeutic window may be that of symptom recognition rather than time since last known normal. Our findings are in accordance to the evidence that clinical and early CT findings in WUS patients are not different from patients with stroke of known onset, [9][10][11][12][13] and suggest that WUS may occur predominantly in a time period shortly before awakening.…”

“…Wake-up stroke (WUS) represents up to 25% of all ischemic strokes, 1 and unknown onset of stroke symptoms with time since last seen well for more than 4 hours and 30 minutes is considered a contraindication for thrombolysis. There is an increasing interest in research to define whether WUS patients benefit from reperfusion therapies in the acute phase, and randomized controlled trials are being conducted.…”

Late Endovascular Revascularization in Acute Ischemic Stroke Based on Clinical-Diffusion Mismatch

“…[15][16][17] Patients in this analysis were seen to generally fall into 1 of 3 categories: those with wake-up strokes, those with well-established long duration of symptoms of the posterior circulation, or those with stenotic nonocclusive lesions and fluctuating neurologic syndromes. These groups may be ideal focuses of intervention in further studies of therapies at later times.…”

Advanced neuroimaging in acute ischemic stroke: extending the time window for treatment

“…Wake-up strokes are not uncommon, accounting for up to 25% of all cases of ischemic stroke. 14,34 Despite being excluded from treatment by current guidelines, patients' wake-up strokes have imaging findings that are often similar to those of patients in whom the time of onset is known.…”