MD Conference Express ISC 2013 - (Page 32)
SELECTED UPDATES ON WAKE-UP STROKE
Wake-Up Stroke
Written by Phil Vinall
Peer-Reviewed
Highlights From
32
April 2013
“Wake-up” strokes occur when an individual wakes up with neurological deficits from a stroke.
The most frequent time of onset for all subgroups of ischemic stroke is between 6 am and
12 pm [Marsh EE et al. Arch Neurol 1990]. Retrospective studies have shown that wake-up stroke
is common, with a prevalence of approximately 14% to 28%. Although tissue plasminogen
activator (tPA) significantly improves outcomes [Hacke W et al. N Engl J Med 2008], patients with
wake-up stroke are often not eligible for this therapy because the medication must be given within
4.5 hours of when the patient was last known to be normal. Epidemiology, clinical features, and
available data for the effectiveness of thrombolytic treatment in patients with wake-up stroke
were described in this session.
Jason Mackey, MD, Indiana University, Indianapolis, Indiana, USA, addressed the
epidemiology of wake-up strokes. The Greater Cincinnati/Northern Kentucky Stroke Study
[GCNKSS] was a large population-based investigation that compared patients with wake-up stroke
with those who were awake at the time of symptom onset [Mackey J et al. Neurology 2011]. Of
1854 patients presenting to an emergency department with ischemic stroke, 14.3% had a wakeup stroke (adjusted wake-up stroke event rate, 26.0/100,000; 95% CI, 22.9 to 29.1). Extrapolated
to the nation as a whole, the authors estimated that 58,000 patients presented to an emergency
department with a wake-up stroke in 2005. The authors also estimated that at ≥35.9% of the wakeup stroke patients would have been eligible for thrombolysis if arrival time were not a factor.
Whether there are differences between wake-up strokes and other strokes is unclear. In
GCNKSS, wake-up stroke patients were more likely to be older. Other studies have suggested that
obesity [Jiménez-Conde J et al. J Neurol 2007] and smoking [Nadeau JO et al. Can J Neurol Sci 2005]
might increase the risk for wake-up stroke.
It is also unclear whether there is a difference in severity between wake-up and awake stroke.
Some studies have shown wake-up stroke to be more severe [Huisa BN et al. J Stroke Cerebrovasc
Dis 2010; Jiménez-Conde J et al. J Neurol 2007; Kim BJ et al. Stroke 2011; Mackey J et al. Neurology
2011], but at least one study has shown awake stroke to be more severe [Fink JN et al. Stroke 2002]
and another found no difference [Serena J et al. Cerebrovasc Dis 2003]. Outcomes have also been
mixed. There was no significant difference in 90-day mortality (approximately 16% in both groups)
in GCNKSS, but 1 recent small study showed that wake-up stroke patients fared better, although
this benefit was not statistically significant [Huisa BN et al. J Stroke Cerebrovasc Dis 2010]. Other
studies have shown that wake-up stroke patients do worse, with patients being less likely to return
home [Nadeau JO et al. Can J Neurol Sci 2005] and having worse functional outcomes at 3 months
[Jiménez-Conde J et al. J Neurol 2007].
Victor C. Urrutia, MD, The Johns Hopkins Hospital Stroke Center, Baltimore, Maryland, USA,
discussed the circadian variation in stroke, and several studies that assessed early ischemic changes
detected on computed tomography (CT) and magnetic resonance imaging (MRI) in patients with
wake-up and awake stroke.
A circadian variation for stroke occurrence appears well established with relative risk for early
morning stroke being 49% compared with the number expected if strokes were distributed evenly
throughout the day (95% CI, 44 to 55; Figure 1) [Elliott WJ. Stroke 1998]. Potential causes for the
circadian rhythm include coagulability [Jafri SM et al. Am J Cardiol 1992]; fibrinolysis [Jovicic A,
Mandic S. Thrombosis Res 1991]; platelet aggregation [Andrews NP et al. J Am Coll Cardiol 1996];
elevated epinephrine, norepinephrine, and cortisol levels; and higher blood pressure in the
morning [Panza JA et al. N Engl J Med 1991; Stergiou GS et al. Stroke 2002].
In a recent study that assessed ischemic changes detected on CT, Huisa and colleagues [J Stroke
Cerebrovasc Dis 2010] found no difference in Alberta Stroke Program Early CT Score (ASPECTS)
between patients whom they named “AWOKE” (patients likely to have wake-up strokes defined as
having a last seen normal time >4 hours but <15 hours, and presenting to the Emergency department
between 4 am and 10 am) and a control group of patients with awake stroke of known onset time.
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Table of Contents for the Digital Edition of MD Conference Express ISC 2013
MD Conference Express ISC 2013
Contents
Defending the Stroke Guidelines
Stroke Update: An Overview of What Is Going on in the Area of Stroke
Brain Imaging Does Not Help Identify Patients Who May Benefit From Endovascular Treatments for Acute Ischemic Stroke
MISTIE II Trial: 365-Day Results Demonstrate Improved Outcomes and Cost Benefit
Addition of AMPLATZER PFO Occluder to Medical Therapy Is Beneficial in Patients With Cryptogenic Stroke and PFO
Intraoperative CT-Guided Endoscopic Surgery for ICH [ICES]
The EMBRACE Trial: Prolonged Ambulatory Cardiac Monitoring Improves the Detection and Treatment of Atrial Fibrillation in Patients With Cryptogenic Stroke
DP-b99 Does Not Improve Recovery Following Acute Ischemic Stroke
The Secondary Prevention of Small Subcortical Strokes Trial: Blood Pressure Intervention Results
Final Results of the Solitaire FR Thrombectomy for Acute Revascularization: The STAR Trial
Clopidogrel Plus Aspirin Reduces Risk of Recurrent Stroke: The CHANCE Trial
Reversal of Chronic Hypoperfusion to Improve Cognitive Function: The RECON Trial
Cardioembolic Stroke
IMS III
Novel Anticoagulants in Vascular Neurology Practice
Wake-Up Stroke
Virtual Reality in Stroke Rehabilitation
Reward Improves Long-Term Retention of a Motor Memory Through Induction of Offline Memory Gains
MD Conference Express ISC 2013
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