The Management of Acute Ischemic Stroke



Until recently, recombinant tissue plasminogen activator (r-tPA) was the only acute ischemic stroke treatment. However, only 4–8% of patients with ischemic stroke truly receive r-tPA, in part due to the limited time window for treatment. In 2008, the ECASS-3 trial prolonged the window for r-tPA eligibility from 3 to 4.5 hours after symptom onset, with additional exclusion criteria which increased r-tPA utilization by as much as 20% in some centres. In 2015, the introduction of advanced endovascular treatment methods further expanded this treatment window to select patients to up to 7 hours from symptom onset. Rapid assessment of suspected stroke patients to regulate eligibility for these treatments, therefore, remains a critical step. Systems and courses to efficiently identify suspected stroke patients as early as possible and quickly deliver acute reperfusion therapy are now commonplace. Further technological advances using tele-stroke and mobile stroke units in the prehospital setting have increased r-tPA utilization and reduced delays to treatment. This review will discuss the most recent progress in acute stroke treatment and improved systems for their delivery in current practice.

The most effective treatment for acute ischemic stroke is timely reperfusion of the causative vessel occlusion via r-tPA and/or mechanical thrombectomy. Reperfusion improves outcomes by dropping the volume of brain tissue injury. Therefore, a small core infarction with a large penumbra (viable but ischemic tissue) is the ideal target for acute reperfusion therapy. As time from initial stroke increases, the penumbra is quickly substituted by infarcted tissue. Therefore, swift reperfusion preserves tissue in the penumbra while reducing the size of the final infarct core, thereby limiting the volume of injured tissue and reducing disability from stroke.


Since 2015, there have been five clinical trials showing the efficacy of endovascular thrombectomy in addition to standard management, typically r-tPA, in refining outcomes of acute ischemic stroke patients with proximal internal carotid artery (ICA) or middle cerebral artery (MCA) occlusions, sensible to severe stroke severity, and presenting within 12 hours of symptom onset. Overall, there was over dual increased odds of a good outcome (independent of activities of daily living) with endovascular therapy compared to standard medical management with no growth in harm such as major intracranial bleeding. Because of these studies, the American Heart Association/American Stroke Association (AHA/ASA) released an update in 2015 to their acute stroke management guidelines that recommended endovascular therapy for these select patients with acute ischemic stroke.

Comments

Post a Comment

Popular posts from this blog

The Genetic Landscape of Cerebral Steno-Occlusive Arteriopathy and Stroke in Sickle Cell Anemia.

Image
Sickle cell disease (SCD) is one of the most common autosomal recessive diseases in humans, occurring at a frequency of 1 in 365 African-American and 1 in 50 sub-Saharan African births. Despite progress in managing complications of SCD, these remain a major health burden worldwide. Stroke is a common and serious complication of SCD, most often associated with steno-occlusive cerebral arteriopathy, but little is known about its pathogenesis. Transcranial Doppler ultrasonography is currently the only predictive test for the future development of stroke in patients with sickle cell anemia and is used to guide preventative treatment. However, transcranial Doppler ultrasonography does not identify all patients at increased risk for stroke, and progressive arteriopathy may occur despite preventative treatment. While sibling studies have shown a strong genetic contribution to the development of steno-occlusive arteriopathy (SOA) in SCD, the only genome-wide association study
Read more

Does Variability of Brain Blood Flow Increase Stroke Risk in Stroke Survivors and After TIA?

Image
Stroke is the second leading cause of death worldwide, and high blood pressure (BP) is the most important treatable factor that increases a person’s risk of having a stroke. Stiffness of the blood vessels supplying the brain (arterial stiffness), possibly due to long-standing raised BP, is also likely to be a factor that increases stroke risk. Such increased arterial stiffness results in the blood flow through these vessels being more pulsatile (throbs faster) than usual, and this increased pulsatility can be assessed by an ultrasound scan. This research is focused on assessing the relationship between the pulsatility of the blood flow through the blood vessels supplying the brain, and the risk of stroke in patients who have already had a stroke or “mini-stroke” in the past, and in particular to see if this relationship can be explained by raised BP alone. The Oxford Vascular Study (OXVASC) recruits all patients with stroke or “ mini-stroke ” from a single population,
Read more

Vitamin D and hypertension

Image
Vitamin D, a fat-soluble prohormone, has wide-ranging roles in the regulation of many physiological processes through their interactions with the vitamin D receptors (VDR). It plays a major role in bones and calcium metabolism. Vitamin D deficiency is not uncommon and it has been associated with many health-related issues, including skeletal and non-skeletal complications. The association of low vitamin D and cardiovascular diseases and risk factors has been explored in both animal and human studies. However, studies and trials on the effect of vitamin D supplementation on cardiovascular risk factors and hypertension are conflicting with inconsistent results. Therefore, large, well-powered randomized controlled trials are warranted. If successful, supplementation with easy and low-cost vitamin D can impact our health positively. Here, we summarized the evidence for the association of vitamin D, cardiovascular diseases and risk factors, including coronary artery diseases,
Read more