Parkinson's Disease

What is Parkinson's Disease?

Parkinson's disease is a progressively degenerative neurological disorder which affects the control of body movements.

Symptoms result from the progressive degeneration of neuronal cells located in the substantia nigra. This causes a deficiency in the availability of dopamine; a chemical neurotransmitter (messenger) necessary for the production of smooth controlled movements.

The symptoms of Parkinson's disease appear when about 70% of dopamine producing cells cease to function normally. Symptoms develop slowly and gradually progress over years, but are greatly helped by drug treatment.

The presentation of symptoms varies greatly between individuals diagnosed and no two people will be affected in the same way. The three symptoms used for diagnostic purposes are:

  • Tremor, (shaking, trembling) is the most well known symptom of PD, but is absent in one third of people when the condition is first diagnosed. Tremor usually begins in one hand and the spreads to the leg, before crossing to the other side. It may also be felt internally. Typically it is most noticeable at rest and when stressed or tired and disappears during movement and when asleep.
  • Rigidity or stiffness of the muscles is a very common early sign of PD whereby the muscles seem unable to relax and are tight, even at rest. You might feel that your muscles will not do what you want them to do. Rigidity may be experienced through the entire range of movement of a joint (called 'lead pipe rigidity') or just in parts (called 'cog-wheel rigidity).
  • Bradykinesia (slowness of movement) occurs because the brain is not able to control smooth and delicate movements. This leads to a lack of spontaneous activity e.g arm swing diminishes, fine motor coordination is reduced e.g. handwriting becomes smaller, and it may lead to freezing or periods of immobility

For more information visit the Parkinson's Disease Association of Australia, Parkinson's Australia