In the September 2001 issue of the American Journal of Neuroradiology (Am J Neuroradiol – 01-SEP-2001; 22(8): 1534-42) a group of clinicians from the Foothills Hospital in Calgary/Alberta had published an article with a scoring system for CAT scans (also abbreviated CT scans) that would be done on every patient with a stroke. By utilizing early CT scans and this scoring system an ischemic stroke (due to a blood vessel that closed off in the brain) could be rapidly assessed. Within 3 hours of the beginning of the stroke the treating physician would know whether the patient would benefit from clot-busting drugs (TPA or tissue plasminogen activator) or not. Dr. Pexman and co-workers had noted that patients with an Alberta Stroke Program Early CT Score (ASPECTS) of less than 7 had a poor survival rate or an outcome with high dependency on caregivers. Patients with a score of 7 to 10 had a much better survival chance and were ideal candidates for the clot-busting therapy. The brain of the stroke patient depicted by CT scans using this method is divided into 10 regions and the findings are systematically evaluated by the radiologist and an ASPECTS score is obtained. Dr. Michael Hill, an assistant professor at the University of Calgary, and one of the co-workers of this initial study has now completed a further follow-up study together with Dr. A.Buchan, director of the Calgary Stroke Program. The results were published in the August 2003 issue of the medical journal “Stroke”. They found that ischemic strokes (from clots in the middle cerebral artery) have the best outcome when detected by CT scan early (within 3 hours of the beginning of the stroke) and if thrombolysis therapy with TPA, the clot-busting drug, is done before 6 hours after the beginning of the stroke.
The lack of blood circulation from a stroke,which closed the middle cerebral artery, is shown in this link. What does that mean in practical terms? Let us assume a patient is suddenly losing all of the strength and movement in one arm and losing speech as well. An emergency CT scan is done right away and it is determined that the patient has had a stroke in the middle cerebral artery. Let us say that the ASPECTS score was between 7 and 10. This patient’s physicians would likely treat the stroke with the clot-busting medicine mentioned being confident that there likely will be a good outcome. In the past, before this therapy was available, many of these patients would end up with a permanent arm palsy without much function and sustain a permanent speech deficit as well. After the clot-busting therapy many of these patients who have a good outlook will now have a considerable, if not full return of function in their arm and regain their speech as well. Unfortunately, the opposite is true as well: those with a poor ASPECTS score below 7 will not be candidates for the clot-busting therapy and will tend to do poorly. This scoring system of early CT scans with strokes (ASPECTS) is already being used in several countries such as Canada, the US, Australia and Europe. “Early detection and intervention in stroke is critical to achieve a positive outcome” said Dr. A.Buchan, director of the Calgary Stroke Program, who is also a professor in the department of clinical neurosciences of the University of Calgary/Alberta. Here is a link for more background on strokes.
Last edited October 26, 2014