Parkinson's DiseaseJul 2008
What is Parkinson's disease?
Parkinson's disease is a common neurological condition affecting 1.5 million people in the United States. The disease is the result of the loss or premature death of cells in a part of the brain called the "substantia nigra." Loss of these cells depletes dopamine, a neurotransmitter that these cells need to communicate with one another.
Parkinson's disease causes four prominent symptoms: slowed movements, shaking tremors, rigidity or stiffness of muscles and difficulty walking. Patients may not suffer all of these symptoms, but all patients will have at least some of these complaints at some point during their illness.
Parkinson's tends to progress over many years and can have a real impact on a person's independence and everyday life. Fortunately, there has been an explosion of treatments for Parkinson's in recent years. These include Sinemet, a tablet that helps increase dopamine in the brain. Additionally, new surgical treatments can help at certain stages of the illness.
Does Parkinson's disease cause memory trouble?
Yes, it can. Although memory loss is not one of the cardinal symptoms of Parkinson's disease, it does occur in some patients. In my experience, memory loss is a phenomenon that patients really worry about.
About 18 percent of patients suffering from Parkinson's disease will develop Parkinson's disease dementia, or PDD. Patients who suffer PDD tend to be older-usually over 70 years of age when first diagnosed with the disease. Patients with PDD suffer impaired ability to plan and execute multistep processes. They frequently have trouble understanding the things they see (for example, recognizing an aspect of a staircase but not understanding its function). They do have relative preservation of their verbal ability when compared to other dementia patients, but PDD patients tend to respond less well to medical and surgical treatments than non-demented Parkinson's patients.
Many times, patients think that since they have Parkinson's disease they will have a higher risk of developing other degenerative diseases like Alzheimer's disease. Fortunately, this is not true.
Are there other conditions that might mimic Parkinson's disease and possibly cause memory trouble?
Yes, some related conditions may look like Parkinson's disease but are not. These diseases, called "Parkinson's plus" syndromes, can look very much like typical Parkinson's disease, yet "Parkinson's plus" diseases are more likely to cause dementia than Parkinson's disease-and at an earlier stage, too. In fact, doctors consider the development of early dementia as evidence for a "plus syndrome" and evidence against a diagnosis of classic Parkinson's disease.
What can a patient do to combat memory loss when he or she suffers Parkinson's disease?
I am asked this question very often. The answer applies to everyone-not just dementia patients or Parkinson's patients. There are many things you can do to keep your brain working well. You might call this the "use it or lose it" advice: Patients who remain mentally active will maintain their cognitive function better than those who do not. The Nun Study, an ongoing research project that began in 1986 and has followed hundreds of nuns over many years, has popularized this "use it or lose it" concept in relation to cognitive abilities. Researchers from several universities have tested the nuns' memories and correlated their cognitive status and post-mortem brain findings with their activities in life. The results have indicated that the nuns who remained mentally active, interested and motivated had a reduced chance of suffering memory loss. One of these nuns, who was over 100 years old, knitted mittens for babies and prayed daily for each of the students she had taught over her long career. This was no easy task, since she had taught many thousands of students in her decades as a teacher. And she had a clear mind when she died at 102.
If you have Parkinson's disease and suffer memory problems, what should you do?
First, tell your doctor. Do not assume you have PDD or other types of dementia until other conditions have been considered and ruled out. For example, it is common for medications to have side effects of memory loss or confusion. A simple dosage adjustment may help.
If your doctor has diagnosed you with dementia, medicines are available to help treat the symptoms of memory loss. The United States Food and Drug Administration has recently approved one of these medicines (rivastigmine, marketed as Exelon) for the treatment of PDD.
H. Blair Marsteller, M.D., is a neurologist in Riverside Medical Group, Hampton Roads Neurology. He has offices in Newport News and Hampton. Dr. Marsteller received his M.D. degree, residency and fellowship training at the University of Virginia in Charlottesville. He also spent two years training at the University of North Carolina at Chapel Hill.