Stroke: Evaluating Stroke Extension

00:01 So next let's talk about the workup for an ischemic stroke.

00:05 And we really approach the workup for a stroke in three phases.

00:09 The first is to evaluate the extent of the stroke.

00:12 And we use our MRI scan or CT to help us determine what is the extent, what's the distribution of the stroke, and how can that tell us what the etiology or cause would be.

00:23 Next, we evaluate the causes of the stroke.

00:25 Strokes come from three areas.

00:27 They can come from the heart, the blood vessels in the neck, or the blood vessels in the brain.

00:32 And we evaluate each of those in our workup for an acute stroke.

00:37 The last is we want to assess for risk factors of stroke.

00:39 And we think about those things that cause arterial or atherosclerosis, hypertension, hyperlipidemia, diabetes, and some other potential contributing factors like sleep apnea, depression, or others.

00:54 First, let's talk about the workup for a stroke and evaluating the extent of the stroke.

00:59 The MRI is really the workhorse test to evaluate the extent of stroke.

01:03 It shows us where the stroke has happened, and we use the diffusion weighted image which we're looking at here on the left, and correlate that with the apparent diffusion coefficient or ADC map.

01:15 These images help us with determining the location of the stroke and again that helps to determine the etiology.

01:21 Lacunar strokes, small islands of punctate ischemic infarct in the deep areas of the brain, like the basal ganglia, thalamus, pons or cerebellum or internal capsule come from long standing hypertension and we really want to manage hypertension in those patients.

01:38 Large vessel strokes as you can see here with this large right MCA stroke tend to come from embolic sources.

01:46 In these situations, we see proximal occlusions like proximal MCA occlusions which contributed to this patient's stroke and those large clots lodged in the proximal vessels and tend to come from an embolic source.

02:00 We can also see a multifocal pattern, as you see here, and in this we think about vasculitis or a showering of emboli and that can help us to work up those potential causes of stroke.

02:11 So the MRI is very important in determining the distribution of stroke and therefore understanding its etiology.