Radiology can lead discussion of stroke therapy issues

May 1, 2006

We have good news to report in this month's cover story: Research in stroke imaging is beginning to widen the window of time in which drug-based or mechanical therapy can be used to preserve brain function following an ischemic stroke. But we have bad news to report as well: More than a decade after research established the value of thrombolytic therapy to revascularize the brain and preserve brain tissue, the use of tissue plasminogen activator for stroke therapy remains stubbornly in the 2% range. Many victims go untreated for the nation's number three cause of death and a leading cause of serious long-term disability.

We have good news to report in this month's cover story: Research in stroke imaging is beginning to widen the window of time in which drug-based or mechanical therapy can be used to preserve brain function following an ischemic stroke. But we have bad news to report as well: More than a decade after research established the value of thrombolytic therapy to revascularize the brain and preserve brain tissue, the use of tissue plasminogen activator for stroke therapy remains stubbornly in the 2% range. Many victims go untreated for the nation's number three cause of death and a leading cause of serious long-term disability.

The good news is pleasing to contemplate. Research has established that imaging, with both MR and CT, can identify areas of the brain that can be saved through quick clearing of the clot that caused the stroke. Clinical experience from some academic medical centers suggests that if a substantial area of salvageable tissue can be seen with imaging, intravascular or mechanical thrombolysis of the clot may still preserve brain tissue even if administered well beyond the three-hour window.

These developments are significant because it is tough to get stroke patients into therapy within the three-hour window for intravenous tPA. Often, stroke symptoms go unrecognized even in the emergency department. Establishing a time of onset can be difficult. To the extent that these obstacles can be minimized by making the three-hour limit less restrictive, the opportunities for successful therapy are greater.

Even if that happens, however, a far bigger obstacle remains to overcome: an emergency care system that has failed to appreciate the value of stroke therapy and develop strategies to assure that it is effectively applied. One example: Our cover story mentions a 2005 survey of ER physicians that found that one-quarter of them would not administer thrombolytic therapy even under ideal circumstances. Two-thirds of them cited the risk of hemorrhage as their reason for withholding treatment. Clearly, the message about the value of imaging for diagnosis and tPA for therapy has not reached a significant segment of this group.

We also found some noteworthy efforts to improve the situation. Guidelines developed by the Brain Attack Coalition and published in 2000 (JAMA 2000;283(23):3102-3109) set out criteria for primary stroke centers. A Joint Commission on Allied Healthcare Organizations initiative to put the guidelines into action had certified 320 facilities as of March 1. That leaves some 2600-plus U.S. hospitals without stroke certification.

Therein lies a big part of the problem. When a facility doesn't have a stroke plan, it's a new discussion every time a potential stroke patient arrives.

Crucial questions-what is the imaging protocol, who reads the images, when is therapy provided, and who provides it-are answered on an ad hoc basis. Time is lost, and potentially successful therapy is sometimes denied.

It is not critical that every hospital provide stroke therapy, but every hospital at least needs to consider the question of whether it should.

That's where radiology can play a crucial role. As the leaders of the imaging team, radiologists should initiate discussions with other specialists and the hospital administration about how to handle stroke imaging and therapy issues.

An effective stroke program is not easy to provide. CT or MR scanners and the techs to operate them must be available 24/7, 365 days a year. Teamwork involves emergency physicians, neurologists, and radiologists. Services need to be provided quickly. Although the window for therapy is opening wider, most community facilities for the time being will be restricted to the three-hour limit for tPA administration.

But it's a worthy goal. As more than one critic has noted, we've solved most of the emergency care problems in trauma and myocardial infarction, but not in stroke care. The diagnosis and therapy elements are well advanced. Now the emergency systems need to catch up.