Diseases And Conditions
Acute hemorrhagic stroke
While the term stroke refers to a loss of neurologic function, the term hemorrhagic stroke refers to a sudden loss of neurological function due to bleeding in the brain. Spontaneous bleeding in the brain can be caused by a number of conditions. These conditions include hypertensive stroke, amyloid angiopathy, bleeding into a previous ischemic stroke (called hemorrhagic conversion), ruptured cerebral aneurysms and vascular malformations of the brain.
Hypertensive hemorrhage is a common cause of hemorrhagic stroke. Hypertensive hemorrhage can occur when there is uncontrolled high blood pressure. Over time, this chronically elevated blood pressure can result in the formation of tiny microscopic aneurysms within the arteries of the brain substance. These tiny aneurysms are called “charcot” aneurysms and are different from the aneurysms that cause subarachnoid hemorrhage. Hemorrhages from these aneurysms occur within the brain substance itself and are usually located in the cerebellum, basal ganglia and brainstem. Treatment of these brain hemorrhages consists of strict blood pressure control and other neurocritical care measures. If patients are seen early enough a transfusion of a blood clotting factor, called factor 7, can be given in an attempt to limit bleeding. If the hemorrhage is large enough, the patient may require surgery as either a life saving measure or to preserve brain function. Even if a hemorrhage has a distinctive hypertensive appearance, a vascular malformation may be at cause in up to 8% of cases. Therefore, some patients may undergo vascular imaging such as angiography.
Amyloid angiopathy is a poorly understood degenerative condition that can result in brain hemorrhage. In amyloid angiopathy characteristic degenerative changes occur in the tiny arteries of the brain. This is really only identified microscopically. These tiny arteries become fragile and leaky, causing hemorrhage. The pattern of brain hemorrhage with amyloid angiopathy is usually lobar, meaning that it will be restricted to a lobe of the brain. The diagnosis of amyloid angiopathy is two fold. Firstly, other causes of brain hemorrhage, like hypertension or vascular malformations will be excluded. Secondly, characteristic tiny microhemorhages can be seen on specialized MRI pictures of the brain. The treatment of brain hemorrhage due to amyloid angiopathy consists of supportive measures, factor 7 transfusions in patients who present early enough and, if needed, surgery.
Hemorrhagic transformation of an ischemic stroke occurs when a plugged brain artery reopens spontaneously. As blood flow is restored to damaged brain, the damaged microscopic arteries and capillaries become leaky, causing a brain hemorrhage into the already damaged or dead brain tissue. Treatment is generally supportive. Surgery can be contemplated as a life saving measure.
A special form of brain hemorrhage is subarachnoid hemorrhage (SAH). This is discussed extensively in another section. SAH is one of the most serious conditions in medicine. Even after urgent surgery patients may remain critical or guarded for some time.
Lastly, vascular malformations of the brain, like arteriovenous malformations (AVM), can cause brain hemorrhage. This is discussed in another section. Treatment of a brain hemorrhage caused by a vascular malformation is generally supportive. If the blood clot is large, surgery may be performed. Surgery to remove the malformation itself may be delayed, depending on the patient’s condition.
