Dr. Ruth Hubbard
Lecturer
Dr. M. Sinead O'Mahony
Senior Lecturer,
University Department of Geriatric Medicine,
University of Wales,
College of Medicine, Wales, UK.
Introduction
Stroke is the second most common cause of mortality in much of the developed world and leads to an estimated 4.4 milllion deaths per year, worldwide.1 It also causes significant morbidity. Thirty percent of patients with a stroke will die within the first three months and half of the remaining patients will have significant long-term disability.
Stroke is particularly a problem of older people. The risk of stroke doubles with each decade of life after 35 years, such that two thirds of all strokes occur in patients over the age of 65 years. People over 75 years are the fastest growing population in North America. Any treatment that improves outcomes in elderly patients with stroke is potentially of huge importance.
Until recently, there was no effective therapy or management strategy to reduce stroke mortality and disability. Two interventions have been shown to result in some benefit--stroke units and aspirin therapy. Stroke Unit care is associated with 70 fewer deaths or dependencies per 1000 patients treated.
Acute ischemic stroke (AIS), or "brain infarction", is most commonly a result of intracerebral artery occlusion due to embolism from proximal sites such as the internal carotid arteries, heart or aorta. Unlike cardiac arrest, where brain viability is measured in minutes, AIS presents with a mixture of salvageable tissue, allowing for a therapeutic window that can last several hours. While the definitive time frame has yet to be pinned down, the generally accepted mantra "Time is Brain" reflects the notion that prognosis is improved by early intervention. The question now is whether there is a role for thrombolytic therapy in the management of AIS.