High Blood Pressure as a Risk Factor for StrokeNo matter what stroke risk factors a person might carry with him, suffering from high blood pressure alone can significantly increase his risk of suffering a hemorrhagic stroke. This risk is even more pronounced in the elderly, in people who smoke, in men, in diabetics, and in people who drink alcohol.
High blood pressure causes intracerebral hemorrhage (ICH) by damaging the fragile walls of small arteries inside the deeper areas the brain. These are the same arteries affected by lacunar strokes, which are so common in white matter areas. However, the area most commonly damaged by ICH is called the basal ganglia. Other parts of the brain affected by bleeding due to high blood pressure include the thalamus and the cerebellum.
In some cases the bleeding caused by high blood pressure is so large that blood spills into the brain's ventricles causing an intraventricular hemorrhage, a condition which can result in life-threatening hydrocephalus.
What Are the Symptoms?The symptoms of ICH caused by high blood pressure vary depending on the location and size of the bleeding. Symptoms can therefore consist of:
- Weakness of the face and/or arm, and/or leg on one side of the body
- Numbness in the face, and/or arm, and/or leg one side of the body
- Inability to understand spoken language or inability to speak
- Inability or difficulty writing or reading
- Vertigo and/or gait imbalance with or without nausea or vomiting
- Severe headache or double vision
In rare cases, the bleeding caused by high blood pressure is so profuse that it leads to a rapid increase in intracranial pressure, which causes patients to become unresponsive, paralyzed or comatose.But by symptoms alone it is not possible to distinguish whether a given stroke is the result of poor blood flow, or profuse bleeding. This is an important reason why special tests are required to diagnose bleeding in the brain (see below).
How Is it Diagnosed?When a person comes to the emergency room with stroke symptoms, physicians routinely perform tests to look for bleeding in the brain. The first test performed usually is a head CT, which is a rapid and reliable way to rule out this possibility. When bleeding is found but the source of the bleeding is not clear, other tests such as a cerebral angiogram or an MRI of the brain with contrast can be performed. These tests help to diagnose other causes of bleeding such as AVM, aneurysms, amyloid angiopathy, or brain tumors.
What Is the Treatment?The treatment of bleeding in the brain from high blood pressure starts by bringing the patient to the intensive care unit for proper stabilization and diagnosis. This is done by physicians who specialize in critical care medicine. Usually, blood pressure is controlled in order to prevent further bleeding. Other possible interventions are decided based on the size of the bleeding, on the severity of the symptoms exhibited by the patient, and on whether the interventions being considered can be expected to make a difference in the overall outcome. In some cases, bleeding must be evacuated immediately, because it threatens to harm the brain. In other cases, the risks of surgery clearly outweigh the potential benefits, leading doctors and families to refrain from further treatment. And in the grimmest of cases, bleeding has caused so much damage to the brain that surgical intervention is futile.
Source: J. P. Mohr, Dennis W. Choi, James C. Grotta, Bryce Weir, Phillip A. Wolf Stroke: Pathophysiology, Diagnosis, and Management Churchill Livingstone; 4th edition (2004)
Sessa M; Intracerebral hemorrhage and hypertension; Neurol Sci. 2008 Sep;29 Suppl 2:S258-9