The basal ganglia is a group of nerve cells located at the base of the brain that control movement of the muscles. Damage to the basal ganglia affects a person's motor ability, or the ability to control bodily muscle movements. A number of diseases are associated with damage to the basal ganglia; all cause problems with movement.
Parkinson's Disease
Nearly a million people in the United States are affected by Parkinson's disease, a chronic, progressive disease that can be treated but not cured. Parkinson's disease is caused by the death of cells in the substantia nigra, a part of the basal ganglia. These cells transmit dopamine, a substance that send information on the body's movement and coordination to the brain. Cell death in the substantia nigra decreases dopamine production, so that muscle impulses are delivered more slowly.
People with Parkinson's disease have different types of movement symptoms which fall into four categories. Seventy percent of Parkinson's patients have tremors that usually affect the hands or feet, but may also affect the facial muscles. The tremors usually affect one side of the body more than the other. Bradykinesia, or slow movement, causes the shuffling, small steps taken by many Parkinson patients. Increased muscle tone, or rigidity, may also occur, giving a masklike facial expression. Postural instability is a loss of coordination that leads to balance issues and increased falls.
Huntington's Disease
Huntington's disease is a hereditary autosomal dominant disease that causes cell death in the basal ganglia. Autosomal dominant means that only one parent needs to pass on the gene for a person to have the disease. Huntington's disease progresses slowly, usually resulting in death 10 to 30 years after the first appearance of symptoms, according to the Mayo Clinic. Early symptoms include personality changes, changes in learning ability, problems with balance and involuntary facial movements. These progress to jerky, involuntary ocular and muscle movements, severe coordination problems, problems swallowing and dementia.
Wilson's Disease
Wilson's disease is an inherited disease that results in copper buildup in the blood. The copper eventually builds up in the brain and damages parts of the basal ganglia. Basal ganglia destruction leads to clumsiness, upper extremity tremors, difficulty walking, speaking and swallowing, and drooling, according to the Mayo Clinic. Wilson's disease is treated with chelating drugs that remove excess copper from the blood.
