Parkinson's Disease - The Who, What and Why

Parkinson's Disease (or PD) is a progressive neurological condition, affecting the central nervous system and impairs functions such as walking, talking and writing. It belongs to a group of diseases called Movement Disorders. It is characterized by muscle rigidity, tremor, a slowing of physical movement or a shutting down of all physical movement. It is named after Dr James Parkinson (1755 - 1824), the London doctor who first identified the disorder in its own.

Parkinson's happens at the loss of nerve cells in part of the brain, known as the substantia nigra. These cells create a chemical called dopamine, which allows messages to be sent to the brain; messages that co-ordinate movement. When these cells deplete, these parts of the brain can’t function properly.

When around about 80% of the chemical has gone, the symptoms of Parkinson’s will appear and the dopamine will continue to deplete slowly over many years. It is unknown to people why the dopamine starts to disappear, but some researchers believe it is likely a lot of factors take part in causing Parkinson’s. These areas of study are genetics and environmental factors.

Genetic Research

As yet, scientists have identified nine genes linked with Parkinson’s. The Parkin gene is most commonly associated with a common form of Parkinson’s. Abnormalities in this Parkin gene at mainly dominant in early onset Parkinson’s disease. Research will also help understand the factors involved in the formation, survival and death of dopamine-producing neurons.

Environmental Factors

There is also evidence that suggests that toxins play a part in killing off the dompamine-creating cells. Chemical such as pesticides and herbicides are thought to have a hand in causing the disorder.

Signs and Symptoms

The symptoms of Parkinson’s can be classified as motor or non motor. Motor symptoms define Parkinson’s with three main features:

- Tremor - usually begins with one hand. First symptom for 70% of sufferers
- Bradykinesia (slowness of movement) - possible difficulty initiating movement or taking longer to make movements
- Stiffness or rigidity of muscles - problems in activities such as standing up from a chair or rolling over in bed

Various non motor symptoms can be:

- Sleep disturbances
- Constipation
- Urinary urgency
- Depression

Parkinsonism

The main symptoms of Parkinson's could also be symptoms of other disorders, as well. The conditions that cause these symptoms are collectively called Parkinsonism. Though Parkinson’s is the most common form of Parkinsonism, there are other, more rare disorders, such as:

- Multiple System Atrophy (MSA)
- Progressive Supraneuclear Palso {PSA)

Parkinson’s can sometimes be referred to as “idiopathic Parkinson’s disease”; this means of no cause.

Statistics

Parkinson’s is a disease that is found all over the world. Exact worldly figures are not always available, but it is estimated at about 4 million people worldwide have the condition.
In the UK:

• 1 in 500 people, estimately 120,000 people, have Parkinson’s
• About 10,000 people are diagnosed every year
• One in 20 diagnosed in a year will be under 40
• Statistically, men are more likely to develop Parkinson’s

The risk of developing Parkinson’s increases with age, and symptoms often appear around the age of 50. However, some people are not diagnosed until their 70’s or 80’s. There is also early onset Parkinson’s disease, which is diagnosed before the age of 40. In addition to early onset, there is juvenile Parkinson’s, which is diagnosed under 18 years of age. Parkinson’s may take months and even up to a year for the symptoms to become obvious enough to consult a doctor. It is not easy to diagnose Parkinson’s, as there are no specified tests that can prove a person has the condition. Diagnosis is generally based on medical history and a clinical examination of the person.

The symptoms of Parkinson usually develop slowly, and in no particular order. Everyone with Parkinson’s may have a different set of symptoms and may respond differently to treatment. Development in treatment has given sufferers a better quality of life. At present there is no cure for Parkinson’s. However, scientists, doctors and researchers are still making advances into the disease, its causes and its best treatment.

Parkinson’s itself does not cause people to die.

Life expectancy for sufferers is that of a ‘normal’ person, with the treatments available today, and none of the drugs used have any strong side effects likely to kill sufferers. However, people who have had Parkinson’s for many years and are severely disabled, their general physical or mental condition could create or help along other illnesses that can cause death.

There is no conclusive evidence that Parkinson is hereditary, apart from in very rare cases (up to 5%). You don’t often find more than one person in a family with the disorder, apart from some families it seems to run in. Generally, Parkinson’s is sporadic. However, some people may inherit a gene susceptible to Parkinson’s disease. This means people with this gene are more likely to develop the disorder with environmental factors such as toxins, like pesticides. There is currently no genetic test for Parkinson’s.

For more information, visit
www.parkinsons.org.uk