More than one million people in the United States suffer from Parkinson disease. This neurodegenerative condition most often occurs after the age of 60 and is slightly more common in men.
Parkinson disease affects an area of the brain called the substantia nigra causing these brain cells to die or become impaired. These neurons produce dopamine, which is the chemical messenger that allows the body's muscles and motor system to function normally. The loss of dopamine neurons results in the inability to control movements properly.
Alzheimer disease is a progressive brain disorder that affects areas of the brain involved in memory, intelligence, judgment, language, and behavior. According to statistics provided by the Alzheimer Association, it is estimated that 5.3 million Americans suffer from Alzheimer disease. The risk for developing Alzheimer disease increases with age and about one in 8 people over the age of 65 is affected by Alzheimer disease. It is the most common form of mental decline or dementia in older adults.
Alzheimer disease may present with a variety of symptoms, however the most common symptom is memory loss. People closest to the individual affected by Alzheimer disease may notice subtle changes that may not be apparent to others or to the individual himself.
Down syndrome is a condition caused by the presence of all or part of an extra copy of chromosome 21. With improvements in care, individuals with Down syndrome are living longer and more productive lives. Adults with Down syndrome appear to age prematurely with physical changes occurring about 20-30 years ahead of other adults.
It has been recently recognized that individuals with Down syndrome are at increased risk for developing dementia and changes in the brain associated with Alzheimer disease. Specifically, amyloid, the protein found in the brain of individuals with Alzheimer disease, has been also found to be present in adults with Down syndrome. These changes in the brain that do not occur in the rest of the population until their late 60’s may appear in people with Down syndrome in their 40’s.
Huntington disease is an inherited, neurodegenerative and progressive brain disease that currently affects approximately 15,000 Americans. Most frequently the symptoms of HD occur between the ages of 30 and 50.
A major breakthrough was made in 1993 when the gene associated with Huntington disease was discovered. It is a familial disease. Each child of a parent with the huntingtin gene has a 50-50 chance of inheriting the gene. At least 150,000 Americans have a 50% risk of carrying the gene and developing the disease.
Multiple sclerosis (or MS) is a chronic, often disabling disease that attacks the central nervous system (CNS), which is made up of the brain, spinal cord, and optic nerves. The symptoms of multiple sclerosis generally appear between the ages of 20 and 40. Typically a person is seen after developing two or more distinct episodes of symptoms that resolve yet are consistent with MS.