Parkinson’s disease or PD is a neurodegenerative disease which means that nervous dysfunction is gradual and progressive. In other words, it develops slowly and gets worse over time. Most PD patients only discover the condition once signs and symptoms, usually those affecting movement, become obvious and affect daily functioning to a level that they need to seek medical advice. However, there are methods to diagnose Parkinson’s disease in the early stages when a person has no signs or symptoms (asymptomatic) or when it is too mild to be evident either to the patient or doctor.
These diagnostic tests should be conducted routinely on patients who are possibly at risk, like those with a familial history. Screening, however, is not as simple as with other conditions as familial Parkinson’s disease accounts for only a small number of cases. Other risk factors like age, gender and environmental factors are too arbitrary to define known risk groups who should undergo routine screening. Most cases of PD are due to unknown cause without clearly identified risk factors.
What is the test for Parkinson’s disease?
There is no definitive test for Parkinson’s disease. Laboratory biomarkers that would normally be identified when testing the blood, other body fluids or tissue samples as is the case with scores of other medical conditions is not available. Instead it is identified by a clinical diagnosis which means that it based on the medical history and findings suggestive of Parkinson’s disease upon conducting a neurological examination.
Imaging techniques like an MRI and CT do not show any clearly identifiable features that is conclusively indicative of Parkinson’s disease. It is known that post mortem examination of the brain of a PD patient shows paleness of the substantia nigra. This is a part of the brain rich in dopamine-producing neurons and the paleness may be visible with the naked eye. Microscopically there may be a noticeable loss of catecholaminergic neurons and Lewy bodies may be found in the remaining neurons.
Genetic Testing for Parkinson’s Disease
Although the most common forms of Parkinson’s disease are not related to inherited genetic abnormalities, it may still be useful for families with a history of PD. Five genetic mutations have been identified in familial Parkinson’s disease and more recently, a new genetic mutation VPS35, has also been discovered. This holds hope for identifying high risk family members and possibly undertaking preventative measures before the onset of the disease. Some genetic abnormalities may not be inherited but rather acquired in life with advancing age or due to environmental factors. Early identification of this genetic damage my also help to identify a person who is more at risk of developing Parkinson’s disease and therefore the necessary steps may be taken at the outset.
The lack of clearly identifiable biomarkers should not discourage those who are apprehensive about developing Parkinson’s disease. Understanding the risk factors, reducing it and identifying the early signs and symptoms and seeking medical attention are all measures that one can undertake to prevent or slow the progression of Parkinson’s disease.