The term degenerative disease refers to a disease that causes the nervous tissue, the nerve cells or the myelin that surrounds the nerves to break down. Parkinson's is a degenerative disease that is caused by the loss of nerve cells in the substantia nigra area of the brain. People with Parkinson's have problems with their movements and posture. There are other degenerative diseases that cause people to have abnormal movements.
Progressive Supranuclear Palsy
Physicians do not know what causes this degenerative disease. They do know that it causes the nerve cells in the brain stem and in the basal ganglia of the brain to break down. People usually start having symptoms when they are middle-aged. First they have problems looking up, then problems swallowing and speaking. They move slowly, have rigid muscles and easily fall backwards. They may have several strokes and eventually develop dementia. Most people die within 10 years of developing this disease, according to David Eidelberg, M.D., Professor of Neurology and Neurosurgery at the NYU School of Medicine in "The Merck Manual for Healthcare Professionals."
Olivopontocerebellar Atrophy
Atrophy is the medical term for the shrinking of an organ. In olivopontocerebellar atrophy, the pons area of the brain shrinks because the nerves in that area have degenerated. There is also a widespread loss of nerve cells in the cerebellum, especially in the outermost areas. This causes atrophy in the cerebellum as well. Most people inherit this degenerative disease, but there are some people who develop this disorder without a family history, writes Ramzi Cotran, M.D., Professor of Pathology at Harvard Medical School in "Robbins Pathologic Basis of Disease." People with this disease have problems speaking, abnormal eye movements, rigid muscles and jerky, uncoordinated movements.
Corticobasal Degeneration
The brain shrinks in corticobasal degeneration, especially in the front and in the areas that affect movement. There are also many swollen nerves. Similar to Parkinson's, people with this disease lose nerve cells in the substantia nigra. In this disease, however, people lose more on one side of the brain than on the other side. The earliest symptoms include clumsiness, mild tremors on one side of the body and rigid muscles. People may then develop twitches, problems with speech and abnormal eye movements. Some people develop dementia. Others develop an unusual problem in which they raise an arm but are not aware that they are raising it, as explained by Allan Ropper, M.D., Professor of Neurology at Harvard Medical School in "Adams & Victor's Principles of Neurology."
Dystonia Musculorum Deformans
Dystonia is a disorder in which the muscles involuntarily contract and distort the posture. There are more than 10 kinds of dystonia musculorum deformans. Most types are hereditary, and the main one is caused by an abnormal DYT1 gene on chromosome 9. The mutation causes abnormalities in the cerebellum and parts of the brain that affect movement. In "Adams & Victor's Principles of Neurology," Dr. Ropper writes that the symptoms usually start when a child is between six and 14 years old. At first, they may turn their foot inwards and hunch their shoulders. As the disease develops, they have problems speaking and swallowing. The muscles of the pelvis, shoulder and spine involuntarily contract and twist.
References
- "Adams & Victor's Principles of Neurology"; Allan Ropper, M.D., Martin Samuels, M.D.; 2009
- "Robbins Pathologic Basis of Disease"; Ramzi Cotran, M.D., Vinay Kumar, M.D., Stanley Robbins, M.D.; 1994
- The Merck Manual for Healthcare Professionals: Progressive Supranuclear Palsy
