Journal of Alzheimers Disease & Parkinsonism
Open Access

Any person who has the signs and symptoms characteristic of Parkinson's disease such as tremor, rigidity, slowness of movement or loss of spontaneous movement and postural impairment is said to have Parkinsonism, but not every person with Parkinsonism has Parkinson's disease. Parkinsonism has many possible causes, and Parkinson's disease is only one of the possibilities. For example, Parkinsonism may be the result off a stroke or a side effect of certain medications. Many other types of neurodegenerative disorders result in Parkinsonism, although Parkinson's disease is the most common of these. In many cases the Parkinsonism found in these other disorders is due to damage to the substantia niagra and more often damage extends to other brain areas as well. People with Parkinsonism may have symptoms of impaired movement, thinking, behavior and other body functions such as blood pressure and sexual, bladder and bowel function that people with true Parkinson's are less likely to develop.

Even considering such differences, Parkinson's disease can be very difficult to distinguish from other forms of Parkinsonism. Patients and their families need to understand Parkinsonism, because some 20% to 25% of people diagnosed with Parkinson's disease will eventually be discovered to have some other form of Parkinsonism. Parkinsonism may look like Parkinson's disease, but over time it does not act like it. Differences that were subtle at the beginning of a disorder often become more pronounced as it progresses. For people with Parkinsonism, the symptoms may become more disabling more quickly or may progress more slowly than in Parkinson's disease.

Parkinsonism symptoms may or may not respond to the medications used to treat Parkinson's disease. Because Parkinson's disease is a progressive disorder, we can generally expect that each year the signs and symptoms of the disease will become more pronounced. Even after the symptoms have become serious enough and clear enough to allow a definitive diagnosis, it is usually years, maybe a decade or more, before a person suffers from a serious disability. Further, treatments are available that can relieve symptoms, so that years, sometimes a decade or more, can go by before symptoms have a significant impact on a person's quality of life. Furthermore, the signs and symptoms of early Parkinson's are only subtly different from those of other disease, some more serious and some less serious than Parkinson's. The similarities among these diseases can make diagnosis difficult, and as frustrating as it may be for a person with Parkinson's symptoms, often the only way to identify Parkinson's disease for sure is to wait and see. No one, not a physician or anyone else, can accurately predict how or quickly the disease will progress in a specific individual. There simply is no reliable way to evaluate the agree of cell loss in the substantia nigra, no laboratory test or widely available imaging procedure that can tell us how much cell loss has occurred or how fast it is progressing. We can say that Parkinson’s is not the kind of disease in which, within a twelve-month period , someone who is able to walk and function independently suddenly finds herself or himself incapacitated and wheelchair-bound. In the average patient, the disorder is very slowly and gradually progressive over years, with relatively mild and subtle changes occurring in the first months to years of illness.