A bleeding stroke, is uncontrolled bleeding from a burst blood vessel within or around the brain, according to the Stanford School of Medicine. A bleeding stroke is also called a hemorrhagic stroke, subarachnoid hemorrhage or intracerebral hemorrhage.
Types
There are two types of bleeding strokes: subarachnoid hemorrhage and intracerebral hemorrhage, notes the Centers for Disease Control and Prevention. Subarachnoid hemorrhage is uncontrolled bleeding within the space between the surface of the brain and skull, caused by either a burst aneurysm or arteriovenous malformation (AVM). Intracerebral hemorrhage is uncontrolled bleeding from an artery deep within the brain, caused predominately by hypertension.
Causes
Both types of bleeding strokes are caused by abnormalities of blood vessel structure, according to the National Institute for Neurological Disorders and Stroke. Structural abnormalities include: aneurysm and arteriovenous malformation (AVM). An aneurysm is a weakening of the blood vessel wall, resulting in a blood-filled bulge. High blood pressure or trauma can burst the bulge, leading to uncontrolled bleeding within the brain. Arteriovenous malformation is a structural abnormality characterized by the weakening of a cluster of blood vessels in the brain, present at the time of birth; the weakened blood vessel can tear, resulting in uncontrolled bleeding within the brain.
Signs and Symptoms
Bleeding strokes have similar signs and symptoms to ischemic strokes--strokes that are caused by a blockage in a blood vessel--according to the Stanford School of Medicine. Signs and symptoms are of sudden onset and include: severe headache, neck pain, transient loss of consciousness; weakness, numbness or paralysis; intolerance to noise or light; and dizziness.
Exams and Tests
Doctors use a number of tools to diagnose a bleeding stroke, according to the National Institute of Neurological Disorders and Stroke. A computerized tomography scan (CT Scan) is a quick tool to visualize the brain tissue with low-dose x-rays. Doctors use a spinal tap to assess the presence of blood in the cerebrospinal fluid. Magnetic resonance imaging (MRI) gives a precise visualization of brain anatomy to determine the location of the stroke. Magnetic resonance angiography (MRA) shows the small blood vessels of the brain. Carotid duplex scanning assesses the blood flow within the carotid arteries using sound waves. Transcranial doplar (TCD) assesses blood flow within blood vessels of the brain with a small probe placed on the skull. Xenon CT scanning measures blood flow within the brain. Radionuclide SPECT scanning provides data on relative blood flow using the radionuclide Technetium99. A PET scan determines the blood flow within the brain by measuring brain cell metabolism. Cerebral angiography uses an injection of a contrast dye into a major artery--usually the femoral artery of the thigh--to assess brain blood flow.
Treatment
According to the Merck Manual, some medications reduce the amount of bleeding. For example, those that decrease high blood pressure or lessen brain swelling. If the area of bleeding is accessible, surgery is performed to stop blood loss. Aneurysms are treated with surgical clipping or endovascular techniques--deployment of a coil into the bulge. Small arteriovenous malformations can be removed with microsurgery; however, radiosurgery and endovascular techniques can be used as well.
