A stroke is the rapidly developing loss of brain function(s) due to disturbance in the blood supply to the brain. This can be due to ischemia (lack of blood supply) caused by thrombosis or embolism or due to a hemorrhage. As a result, the affected area of the brain is unable to function, leading to inability to move one or more limbs on one side of the body, inability to understand or formulate speech, or inability to see one side of the visual field. Stroke was called cerebrovascular accident or CVA earlier.
A stroke is a medical emergency and can cause permanent neurological damage, complications, and death. It is the leading cause of adult disability in the United States and Europe. In the UK, it is the second most common cause of death; the first being heart attacks and third being cancer. It is the number two cause of death worldwide and may soon become the leading cause of death worldwide.
Risk factors for stroke include advanced age, hypertension (high blood pressure); previous stroke or transient ischemic attack (TIA), diabetes, high cholesterol, cigarette smoking and atrial fibrillation. High blood pressure is the most important modifiable risk factor of stroke.
Definition of stroke
The traditional definition of stroke, devised by the World Health Organization in the 1970s; is a “neurological deficit of cerebrovascular cause; persisting beyond 24 hours or is interrupting death within 24 hours”. This definition reflecting the reversibility of tissue damage.
The 24-hour limit divides stroke from transient ischemic attack; which is a related syndrome of stroke symptoms that resolve completely within 24 hours. With the availability of treatments that, when given early, can reduce stroke severity, many now prefer alternative concepts, such as brain attack and acute ischemic cerebrovascular syndrome (modeled after heart attack and acute coronary syndrome respectively), that reflect the urgency of stroke symptoms and the need to act swiftly.
A stroke is occasionally treated with thrombolysis (“clot buster”), but usually with supportive care (speech and language therapy, physiotherapy and occupational therapy) in a “stroke unit” and secondary prevention with antiplatelet drugs (aspirin and often dipyridamole), blood pressure control, statins, and in selected patients with carotid endarterectomy and anticoagulation.
Stroke survivors who believe they can protect themselves from having another stroke had more than twice the blood pressure reduction of nonbelievers, according to preliminary research to be presented in Honolulu at the American Stroke Association’s International Stroke Conference 2019. High blood pressure is a leading risk factor for stroke and stroke recurrence. Studies have shown that patients’ health attitudes and beliefs play a big role in how they take care of themselves.
Blood pressure after a stroke
To determine whether specific beliefs have the power to lower blood pressure after a stroke, researchers studied a multi-ethnic group of 434 adults (average age 64, 50% women, and roughly one third white, black or Hispanic) who survived mild or moderate strokes or transient ischemic attack, also known as TIA or mini stroke. Patients agreed or disagreed with statements like: “I worry about having a stroke,” “I can protect myself against having a stroke” and “Some people are more likely to have stroke than others.”
Researchers found nearly 78% of the adults agreed that they could protect themselves from another stroke. Adults who agreed with that statement, alone, had an average 6.44 mm Hg greater reduction in systolic (the top number) blood pressure a year after their initial strokes, compared with adults who did not feel empowered. “Certain health beliefs, such as those related to patient empowerment, may play an important role in secondary stroke prevention,” researchers said. The National Institute of Neurological Disorders and Stroke funded the study.