Unlike other diseases, there is no specific diagnostic investigation that will confirm a diagnosis of Parkinson’s disease or predict who will develop the disease for all cases. Therefore routine screening is not necessary. However, understanding the risk factors may assist with assessing those individuals with a greater chance of developing Parkinson’s disease.
Risk Factors for Parkinson’s Disease
The biggest single risk factor associated with contracting Parkinson’s disease is old age; men also stand a higher chance of it than do women. Family history is also another factor particularly when a first generation family member has the disease, if this family member is a parent or sibling then chances are estimated to double for yourself to developing the disease. It is thought that this increased risk is due to a number of factors including genetic and environmental which close relations have in common.
The one single factor which has been most consistently associated with a reduced risk of Parkinson’s disease is smoking, the exact reasons for this has never been determined but smoking does seem to offer some protection against developing Parkinson’s disease. However the negative effects that smoking has on our health far outweighs the benefit of not developing Parkinson’s from smoking, it should by no means be considered as a way of preventing the disease.
Most cases of Parkinson’s disease are thought to come about as a result of environmental factors and possible interactions of genes. Environmental factors such as the build up of weak toxins may eventually lead to Parkinson’s in those people who are genetically predisposed. The actual identity of these toxins is unknown but several risk factors due to the environment have been identified through epidemiological studies.
One factor that is persistent however is the finding that rural living, exposure to drinking water from wells and agricultural work increases the risk of developing Parkinson’s disease. This could suggest that pesticides and herbicides might play a crucial role or at the very least contribute to the development of the disease.
However it should be remembered all these factors by no means will determine that you will develop Parkinson’s disease because many people who are constantly confronted with these factors never do develop the illness.
While there are several genes that are thought to contribute to Parkinson’s disease it should be noted that they are a factor which only accounts for a very small amount of the cases diagnosed. One of the most noted genes is called the parkin; this gene creates a protein which it was named after, parkin.
Its role is to help breakdown defective proteins inside the brain cells, when the gene is altered this leads to function impairment. For a person to develop Parkinson’s disease two altered copies of parkin are needed.
This type of inheritance is called autosomal recessive and requires that one copy of the recessive gene is inherited from each parent. Developing Parkinson’s disease this way usually occurs with people in their 40`s, with parkin being the most common of genetic causes of Parkinson’s disease.
Diagnosing Parkinson’s Disease
There are no specific tests used to aid in the diagnosis of Parkinson’s disease, a correct diagnosis relies on two out of three major signs being met. The three major signs of Parkinson’s are, tremor of limbs while resting, rigidity in the muscles and bradykinesia.
Other factors will also be taken into account such as the absence of secondary causes such as multiple small strokes and antipsychotic medication. Of the three conditions those suffering from Parkinson’s are usually more generally aware of tremor and bradykinesia.
In order to make a correct diagnosis the doctor will perform a neurological examination which is of a set standard. This examination will involve a variety of simple tests based on reactions, reflexes and movement.
Parkinson’s Disease Tests
- Testing for bradykinesia is determined by how quickly the person can tap their finger and thumb together or stamp their foot on the ground.
- Tremor is diagnosed by simple inspection of the hands at rest.
- Rigidity is testing by turning the patients neck, upper limbs and lower limbs while the patient is in a relaxed position.
Postural instability is tested by performing a pull test on the patient, during this test the patient will stand in front of the doctor and they will then ask the patient to try and maintain their balance while being pulled backwards towards the doctor. The pull will be made briskly in order to access the patient’s ability to recover, while of course making sure that the patient is actually prevented from falling.
The examination will take into account of course the full medical history of the patient, with care being taken for exposure to medications that could block the dopamine function of the brain. There are several other drugs which can have the same properties and your doctor will always ask for a full history of any medications you are not only currently taking but also those which the patient has taken in past years.
It is worthwhile mentioning that there are several other conditions which give very similar symptoms to Parkinson’s disease and which can sometimes be mistakenly diagnosed as Parkinson’s.
- Essential tremor – the only symptom present in this disease is tremor.
- Progressive supraneuclear palsy – this disease is often characterized by the inability to look downward .
- Multiple system atrophy – this disease is characterized by prominent autonomic symptoms.
- Vascular parkinsonism – this is caused by the person having multiple small strokes.
- Carbon monoxide poisoning.
- Manganese poisoning.
- Certain pesticides.