Sudden impairment of brain function due to hypoxia, which may cause death of brain tissue. Hypertension, atherosclerosis, smoking, high cholesterol, diabetes, old age, atrial fibrillation, and genetic defects are risk factors. Strokes due to thrombosis (the most common cause), embolism, or arterial spasm, which cause ischemia (reduced blood supply), must be distinguished from those due to hemorrhage (bleeding), which are usually severe and often fatal. Depending on its site in the brain, a stroke's effects may include aphasia, ataxia, local paralysis, and/or disorders of one or more senses. A massive stroke can produce one-sided paralysis, inability to speak, coma, or death within hours or days. Anticoagulants can arrest strokes caused by clots but worsen those caused by bleeding. If the cause is closure of the major artery to the brain, surgery may clear or bypass the obstruction. Rehabilitation and speech therapy should begin within two days to retain and restore as much function as possible, since survivors may live many more years. Transient ischemic attacks (“mini strokes”), with short-term loss of function, result from blockage of blood flow to small areas. They tend to recur and may worsen, leading to multi-infarct dementia or stroke.
Learn more about stroke with a free trial on Britannica.com.
Historically, the word "apoplexy" was also used to describe any sudden death that began with a sudden loss of consciousness, especially one where the victim died within a matter of seconds after losing consciousness. Those reading historical documents should take into consideration the possibility that the word "apoplexy" may be used to describe the symptom of sudden loss of consciousness immediately preceding death and not an actual verified disease process. Sudden cardiac deaths, ruptured cerebral aneurysms, certain ruptured aortic aneurysms, and even heart attacks may have been described as apoplexy in the distant past.
In both pituitary and adrenal apoplexy, the word apoplexy refers to both hemorrhage with the gland and to accompanying neurological problems such as confusion, headache, and impairment of consciousness.
Researchers from Chang Gung Memorial Hospital detail new studies and findings in the area of pituitary apoplexy.(Clinical report)
May 24, 2010; New investigation results, 'Clinical features and surgical outcome of clinical and subclinical pituitary apoplexy,' are...