I can’t belive a month has gone by since my last post. Time flies when you are not paying attention and losing focus can derail your progress. Time to dig in the heels, I’ve got a two month clock that just started counting down, I’m going to a professional conference in June and I want to show off the new me!
March 2011 posts
The Multiple Sclerosis Center at Swedish Neuroscience Institute is hosting its Second Annual Multiple Sclerosis Center Art Show at the Bellevue Arts Museum on Saturday and Sunday, June 18 & 19, 2011 from 11:00am to 5:00pm. There will be an ‘Artist Only Meet ‘n’ Greet, Sunday June 19th from 3pm – 5pm
Washington State has one of the high est stroke mortality rates in the nation. To improve this situation, acute intervention al therapies for stroke are being employed to restore circulation to ischemic brain tissue that surrounds areas of completed infraction, while avoiding risk of hemor rhage due to reperfusion of large areas of infracted brain tissue.
Urgent thrombolysis with intrave nous alteplase is the only therapy known to improve clinical outcomes following acute stroke. Unfortunately, alteplase has had limited usage because many patients arrive in an emergency department after the three-hour treatment window. The FDA has also approved two clot removal devices based on the ability to restore circulation. These devices are used up to eight hours after symptom onset. Several approaches to improved acute stroke care are now under way, including extension of the thrombolysis window to 4.5 hours, identification of safer thrombolytic agents and research identifying brain at risk of in farction following a stroke.
A recent European study demonstrat ed the efficacy of alteplase up to 4.5 hours after ischemic stroke in patients younger than age 80 years who have neither dia betes mellitus or prior stroke. The safety profile during this longer window for these patients appears similar to that at three hours.
Another promising advance employs a new thrombolytic agent called des moteplase.
Since its introduction in 1982, transcranial doppler ultrasound (TCD) has evolved into a portable, multimodality, noninvasive method for real-time imaging of intracranial vasculature.
The detection of cerebral microemboli is among the more remarkable capabilities of TCD. Emboli create countable signals in the ultrasound display due to the higher reflection of sound waves compared to the blood cells. Experimental models have shown a high sensitivity and specificity for detection of a variety of substrates, including thrombotic, platelet and atheromatous emboli.
Microembolic signals (MES) within the intracranial vasculature are most frequently identified in patients with large-vessel atherosclerotic disease, such as carotid stenosis. They have also been reported in intracranial arterial stenosis, arterial dissection, cardiac disease and atheroaortic plaque. Additionally, they have been seen in arteries distal to coiled aneurysms.
There is strong evidence that MES detection predicts future ipsilateral stroke risk in patients with symptomatic carotid stenosis (Markus HS, et al.; King A, et al.). A recent study of patients with asymptomatic carotid stenosis demonstrated that MES predicted subsequent ipsilateral stroke and TIA, and also ipsilateral stroke alone, and that it is helpful in selecting patients who will benefit from carotid endarterectomy (Markus, HS et al.).
Identification of active embolization provides crucial pathophysiological information to the neurologist and can also aid in the selection of tailored therapy aimed at reducing the risk of stroke. Emboli from different sources have unique compositions and require specific therapy, such as antiplatelet agents for emboli from large artery atherosclerotic plaque and anticoagulants for cardiac emboli.
Future advances in TCD technology will permit full automation and better identification of the composition and size of circulating embolic materials, thus improving its value for patients with cerebrovascular disease.
Contact Colleen Douville, RVT, at firstname.lastname@example.org or 206-320-4080, for more information about TCD for detection of cerebral microemboli.