Parkinson's disease (PD) is a neurological condition marked by its affect on movement, including shaky hands (resting tremor), rigidity and difficulty walking. It most commonly affects those older than 60, but its onset can be found in people as young as 30. Although extensive research is being conducted, no cure has been found. However, the movement dysfunction can sometimes be controlled through medications or certain surgical procedures.
Parkinson's Disease
Many conditions have Parkinson's-like features, but PD is still considered a single disorder. It's uncertain what exactly causes PD and why some people get it and others don't. The origins are being closely studied, as it has very occasionally proved to be the result of a single gene. In other unusual circumstances, it has been directly related to environmental factors. According to the Michael J. Fox Foundation, the answer is likely somewhere between those, with several genes being influenced by environmental factors to trigger the disease.
Parkinsonism
Parkinsonism refers to other disorders with PD-like symptoms. The Mayo Clinic separates these into two main categories: Parkinson's Plus and secondary Parkinson's. Parkinson's Plus has Parkinson's symptoms and some additional symptoms. These tend to have a worse prognosis than PD. Secondary Parkinson's symptoms can be attributed to other known disorders. These can generally be diagnosed through tests, such as CT or MRI scans. These tests are also done to rule out PD, for which there is no specific diagnostic test. Rather, it's diagnosed by a review of a person's medical history and a thorough neurological exam. The combination of history and the presence of at least two of the primary symptoms differentiate PD from these other diseases.
Other Movement Disorders With PD Characteristics
Because no definitive test has been found to diagnose PD and several of the basic symptoms of the disease can be found in other disorders, it isn't unusual for PD to be misdiagnosed. Many movement disorders feature one or more of the common symptoms of PD. These include essential tremor, which manifests primarily as shaking hands; dystonia, characterized by involuntary muscle contractions; or drug-induced PD (also called medication-induced PD), in which some medications--such as neuroleptics or anti-emetics--affect dopamine levels, much the same way PD does and cause PD-like symptoms. In the case of drug-induced PD, stopping or changing medications reverses PD-like symptoms.
Because it's so easy to misdiagnose Parkinson's disease, it's best to see an experienced neurologist if you think you may have this condition.
