Pathophysiologic mechanisms, neuroimaging and treatment in wake-up stroke

Abstract

Wake-up stroke (WUS) or ischemic stroke occurring during sleep accounts for 14%–29.6% of all ischemic strokes. Management of WUS is complicated by its narrow therapeutic time window and attributable risk factors, which can affect the safety and efficacy of administering intravenous (IV) tissue plasminogen activator (t-PA). This manuscript will review risk factors of WUS, with a focus on obstructive sleep apnea, potential mechanisms of WUS, and evaluate studies assessing safety and efficacy of IV t-PA treatment in WUS patients guided by neuroimaging to estimate time of symptom onset. The authors used PubMed (1966 to March 2018) to search for the term “Wake-Up Stroke” cross-referenced with “pathophysiology,” ‘‘pathogenesis,” “pathology,” “magnetic resonance imaging,” “obstructive sleep apnea,” or “treatment.” English language Papers were reviewed. Also reviewed were pertinent papers from the reference list of the above-matched manuscripts. Studies that focused only on acute Strokes with known-onset of symptoms were not reviewed. Literature showed several potential risk factors associated with increased risk of WUS. Although the onset of WUS is unknown, a few studies investigated the potential benefit of magnetic resonance imaging (MRI) in estimating the age of onset which encouraged conducting clinical trials assessing the efficacy of MRI-guided thrombolytic therapy in WUS.

Safety and efficacy of intravenous thrombolytic treatment in wake‐up stroke: Experiences from a single center

“…The timing of the onset of strokes is not distributed evenly over the 24 hr in a day (Elfil et al, 2019). Similar to myocardial infarctions, ischemic strokes are more common in the morning.…”

Accuracy of Brain MRI Interpretation of Emergency Medicine Specialists Versus Radiologist and Neurologist in Suspected Acute Ischemic Stroke Patients; a Diagnostic Accuracy Study

“…AIS treatment outcome is highly dependent on the start point, and every 1-minute delay leads to the destruction of a considerable number of neurons. It is more important because based on recent researches, some of wake up stroke and unknown time stroke cases may benefit from thrombolytic therapy (2,7,8). MRI-guided thrombolytic therapy in AIS patients with unknown time of onset has become a topic of ongoing researches.…”

“…MRI-guided thrombolytic therapy in AIS patients with unknown time of onset has become a topic of ongoing researches. It is likely that in those patients who have an ischemic lesion that was visible on DWI stereotypes of brain MRI, which is not accompanied by correlated parenchymal hyperintensity on FLAIR, the stroke had occurred approximately within the previous 4.5 hours (2,9).…”

“…Although in the proposed algorithm for thrombolytic therapy in patients with acute ischemic stroke (AIS), there is no place for this diagnostic procedure (1); however, there may be an indication in wake up stroke and unknown time stroke cases. Such patients who were pre-viously considered contraindicated for thrombolytic therapy may benefit from this treatment if there is a mismatch between fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) images of brain MRI (2). However, in some instances, differentiation of AIS from other differential diagnoses may be promptly required in which brain MRI is done.…”

Impact of Obstructive Sleep Apnea on Cognitive and Motor Functions in Parkinson's Disease

“…Clinically, OSA results in symptoms of excessive daytime sleepiness, memory problems, nocturia, and non‐refreshing sleep 16,20 . Without proper management, OSA is associated with critical health consequences such as refractory hypertension, 21 cardiovascular diseases, 22 depression, cognitive slowing, 23 metabolic disorders, 20 disturbance of glucose homeostasis/diabetes, 24 and increased risk of ischemic stroke 25 . Therefore, it is important to diagnose OSA in a timely fashion and manage it properly, especially in patients with symptoms suggestive of OSA.…”