Parkinson's Disease

Parkinson's disease is a progressive neurological disease. The region of the brain known as the substantia nigra produces dopamine that is responsible for many of our motor functions, including muscle and bowel movement, as well as playing an important part in our mental health. The symptoms of Parkinson's disease appear when a patient has lost about eighty per cent of their dopamine producing capability.

The incidence of Parkinson's disease is in the region of one in every five hundred people will eventually show symptoms of Parkinson's disease, the incidence increases with age and most sufferers are over fifty. One in twenty sufferers will be under forty.

Often patients do not attend the doctors for a while after first developing symptoms but the sooner specialists are involved in diagnosis and treatment the better the long-term outlook generally. The early symptoms are ones of fine motor control, that is a tremor, usually in one hand initially. Patients will often also complain of depression and urge to urinate. They are often constipated. Patients will often not link these symptoms together.

As the disease progresses patients notice a stiffness of movement, with muscles seeming to be rigid. Starting a movement is often the most difficult part, and patients may adopt strategies for dealing with this. This problem leads to a distinctive shambling gait. Handwriting is often distinctive, becoming smaller and smaller over time.
As time progresses patients lose facial expression, and may start to dribble. Some of these symptoms are due to a relative over supply of acetylcholine, the natural counterbalance to dopamine in the brain.

At this time only some of the causes of Parkinson's disease have been identified and by the majority are defined as idiopathic, that is no known cause. Some causes are known, head injury, environmental toxins, drugs, legal and illegal, and genetics. Genetics seems to play a particular role in early onset Parkinson's disease.