Brain Disorders

Any of the various disorders associated with the human brain, including stroke, trauma, and tumors.

It has recently been reported that neurology, the study of the brain, is the fastest growing specialty in the life sciences. With this growth has come a wealth of new information about the origins of and treatments for some of the more prevalent brain disorders. There are many varieties of brain disorders that affect humans, including Alzheimer's disease, Parkinson's disease, epilepsy, and other disorders that are more generally thought of as being "behavioral" rather than biological. These types of disorders that could be termed disorders of the brain in a broad sense include depression, schizophrenia, and bipolar disorder. Beyond these, however, are several other types of disorders of the brain, including stroke, trauma, brain tumors, and developmental disorders such as muscular dystrophy and cerebral palsy.

Strokes are the third leading cause of death in the United States and are one of the leading causes of disability among older adults. According to the most recent statistics, a staggering 1,200 people suffer from strokes each day in this country. "Stroke" is technically a lay term; when physicians speak of strokes, they are referring to thromboses, hemorrhages, or embolisms. Basically, the term stroke refers to the loss of blood to a part of the brain and the resulting tissue damage. Because of the variables involved, strokes are often not correctly diagnosed. Often, especially with very mild events, a patient will attribute odd sensations to something else. The effects of a stroke may vary, based on its origins and the area of the brain that was deprived of blood. Generally speaking, if tissue damage occurred in the right brain hemisphere, the victim may experience some degree of paralysis on the left side of the body, a distortion of vision, especially the ability to perceive depth and distance, and a loss of memory. If the tissue affected is on the left side of the brain, patients may experience some degree of paralysis on the right side of the body, minor memory loss, and some degree of language loss.

Other common brain disorders include the array of conditions caused by head trauma. Injuries to the head can, obviously, vary tremendously, but such injuries all result in biochemical abnormalities in the brain. After the head has been injured in some way, a tremendous amount of chemicals travel through the brain, which often have detrimental effects on brain cells, including paralysis and behavioral and cognitive losses. Recent medical advances have uncovered some drugs and treatments that can offset this after-effect of trauma, and physicians now know that brain cells can be replaced in adults, a procedure that was thought impossible only a decade ago. Doctors now have the ability to procure accurate images of the brain from magnetic resonance imaging (MRI) machines, allowing them to pinpoint damaged areas for treatment.

The incidence of brain tumors has increased in recent years, although it is not certain if this trend is simply a result of better diagnostic technology, such as MRIs. Nonetheless, treatments devised thus far have generally been less than stellar. Researchers have found that certain genes inside tumors are capable of creating resistance to drugs being used to destroy the tumor. Often, if drug treatment of brain tumors is ineffective, surgery is required to remove the tumor, which can further damage the brain.

Developmental neurologic disorders of the brain include well-known brain diseases such as Alzheimer's, Parkinson's, muscular dystrophy, and cerebral palsy. Most of these disorders are now known to be inheritable, passed from one generation to another genetically. Recent research has isolated the gene that causes strains of Alzheimer's, Huntington's disease, and several other muscular disorders. Cerebral palsy, a devastating developmental neurologic disorder involving severe muscle and coordination deterioration, has been attributed to stroke in newborn infants.

In 1995, the National Institutes of Health (NIH) spent the following studying brain disorders: Alzheimer's disease, $305 million; stroke, $116 million; multiple sclerosis, $80 million; Parkinson's disease, $72 million; epilepsy, $55 million; and head injury, $51 million. As a way of comparison, NIH spent $199 million studying arthritis in 1995.