The brain is the creator and regulator of personality, thought, conscious and unconscious action, and emotion. The brain is composed of nerves, which are specialized cells that "talk" to each other through electrical impulses. When these electrical signals are impeded due to injury or disease, the brain cannot function optimally. The severity of the injury or disease determines the impact on brain function. There are several types of brain diseases, all of which have the potential to be fatal.
Brain Tumor
Over 35,000 people in the United States are diagnosed with brain tumors every year, according to the National Cancer Institute. Tumors are either benign, meaning they are not cancerous, or malignant, meaning they are. While benign brain tumors usually have a slower rate of growth and do not spread to other sites in the body, malignant cancer cells often grow rapidly, and can spread, a process called metastasis. Malignant brain tumors cause the death of adjacent normal brain tissue, and can cause brain injury by exerting pressure on normal brain tissue.
Stroke
The National Institute of Neurological Disorders and Stroke reports that stroke-related brain injury causes 160,000 deaths in the United States each year. Just as other organs in the body need nourishment and oxygen provided by circulating blood, the brain also needs blood to survive. However, when the flow of blood through blood vessels is disrupted, the result is a stroke. Two major types of stroke are ischemic and hemorrhagic. Ischemic strokes occur when there is a blockage in a blood vessel in the brain; hemorrhagic strokes, or bleeding in the brain, occur when a blood vessel is injured. Both types of stroke may be serious, but ischemic strokes tend to have a more positive prognosis.
Epilepsy
Epilepsy is a brain disease in which abnormal electrical signals occur between the nerve cells of the brain. The result of this abnormal electrical activity is a seizure, which can have varying levels of severity. Seizures include symptoms such as a temporary reduction in the level of consciousness; muscle spasms affecting muscles in one part of the body, such as the face; complete relaxation of the muscles causing the person to drop to the ground; or loss of consciousness with whole-body convulsions.
Traumatic Brain Injury
Traumatic brain injury (TBI) results after physical injury to the brain tissue. A person may have temporary or permanent changes in brain function as a result of a TBI. Depending on the severity, TBIs can cause a transient loss of consciousness, coma or death. "The Merck Manual for Healthcare Professionals" describes how TBIs can cause brain damage directly by physical injury or blood vessel rupture in the brain or indirectly by causing a dangerous increase in the pressure within the skull.
