Doctors first split strokes into leaks and plugs back in 1823
A stroke is either a plug, where blood flow is blocked, or a leak, where a vessel bursts inside the brain. That distinction dates to 1823. The leaks, called intracerebral haemorrhages, are the rarer kind but among the deadliest: about 44 percent of people affected die within a month, and roughly a fifth recover well.
An intracerebral haemorrhage is sudden bleeding into brain tissue, into the fluid-filled ventricles, or both. Symptoms depend on how much blood escapes, how fast and where. They can include headache, weakness or numbness down one side, trouble speaking, seeing or balancing, vomiting, seizures and a falling level of consciousness. A growing clot raises pressure inside the skull, which can push parts of the brain out of place. Bleeds deep in the basal ganglia or thalamus often paralyse the opposite side of the body, while those in the cerebellum can cause vertigo and clumsiness and sometimes block fluid drainage.
High blood pressure is the strongest risk factor, raising the odds of a spontaneous bleed two to six times, and long-term control of it has been shown to cut incidence. Cerebral amyloid angiopathy, in which amyloid beta builds up in small vessel walls and weakens them, is another major cause. Alcoholism, blood thinners, cocaine and even low cholesterol add risk; the link with smoking is weak. Aneurysms, malformed vessels, tumours and head injuries can also trigger bleeding.
Estimates put incidence at about 24.6 cases per 100,000 person-years, with men and women affected at similar rates in that analysis, though other figures describe it as more common in males. Age matters enormously: people 85 and over are 9.6 times likelier to have one than the middle-aged. In the United States it makes up around 20 percent of cerebrovascular disease and about 10 percent of stroke admissions. Bleeding within the brain substance itself is more likely to kill or disable than a blocked-artery stroke, so it counts as an immediate emergency.
Diagnosis usually relies on a CT scan, and care generally takes place in intensive care with tight blood pressure targets. Clinicians try to reverse anticoagulation, keep blood sugar normal, and may insert a drain to relieve fluid build-up; corticosteroids are usually avoided. Surgery to remove the clot is sometimes used, yet trials have not shown a clear benefit, and researchers are now studying whether white matter fibres survive inside the clot itself.
Source: Intracerebral hemorrhage
