Four Helpful Stroke Studies

Mark J. Alberts, MD


November 28, 2012

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Hello. I am Dr. Mark Alberts, Professor of Neurology at Northwestern University in Chicago. Welcome to this Medscape stroke update. Today I would like to talk to you about 4 recent clinical studies that were published in the September 2012 issue of Stroke. All 4 of these studies touched on issues that are of clinical importance.

The first study was by Baracchini.[1] He and his colleagues from the University of Padua examined 75 patients with transient global amnesia (TGA) and 75 control subjects. The purpose of the study was to determine how common and significant jugular venous insufficiency was with respect to the development of TGA. As you know, there has been debate in the literature about how much jugular venous insufficiency contributes as a causative agent to the development of TGA.

Using transcranial Doppler ultrasonography, the authors found that 71% of patients with TGA had evidence of jugular venous insufficiency compared with only 29% of control subjects. However, during the Valsalva maneuver, there was no evidence of a change in jugular venous flow, velocity, or direction. Therefore, although venous insufficiency may be more common in TGA patients, there is no evidence of a causative role in venous congestion or any type of direct pathophysiology that could cause TGA. This is an area of ongoing concern and we will have to see what further studies show.

Another study in the same issue of Stroke, by Riedel and colleagues,[2] looked at a different way to reconstruct head CT scans. Usually we have CT scans with 5-mm slices. These authors reconstructed the CTs using a slice thickness of only 0.6 mm. They found that with thinner-cut reconstructions of 0.6 mm, they were much better able to detect small clots in the M1 trunk and distal middle cerebral arteries (MCA) in people with fairly large ischemic strokes. Perhaps this is one step forward in terms of doing thinner slices to see if we could better detect clots in the MCA and MCA branches. We will have to see if other studies are able to confirm this finding.

Another study, by Rosso and colleagues,[3] looked at the issue of intense insulin therapy vs standard insulin therapy in about 180 patients with ischemic stroke and diabetes. The intense insulin therapy used intravenous insulin to get blood sugar levels under control; standard therapy used subcutaneous insulin. At the end of the study, the investigators found that the intense insulin therapy was more effective in bringing down blood glucose levels, which makes sense.

However, the intense insulin therapy was associated with larger growth of the infarct at the end of the study. Additionally, intense insulin therapy showed no benefit in clinical outcome in terms of modified Rankin scale, death, or dependency at the end of the study. This is one of several recent studies that have shown that although intense insulin therapy can more effectively control blood sugar, at the end of the day it does not seem to have a beneficial effect on clinical outcomes.

The last study I am going to talk about was done by Sundseth and colleagues,[4] again in the September 2012 issue of Stroke. They compared early mobilization (ie, getting patients up within 24 hours if they had an ischemic stroke or an intracerebral hemorrhage) with delayed mobilization (24-48 hours after stroke onset). They found that patients with early mobilization had much worse clinical outcomes in terms of death, dependency, and complications.

Our stroke protocol, as well as those of many other stroke centers, mandates that patients with acute stroke stay on bedrest for the first 24 hours. This study, which was prospective and randomized, seemed to show that that is the best thing to do for these patients: Keep them on bedrest for 24 hours, and then if they are stable, mobilize them.

That is all for this Medscape stroke update. We rapidly reviewed 4 studies that are very new and that I think have clinical implications in terms of causes of stroke and how we should manage these patients. Thank you very much for your attention.