VOL: 102, ISSUE: 01, PAGE NO: 21WHAT IS IT?
WHAT IS IT?
- Parkinson's disease is a progressive neurological disease. It is the most common serious movement disorder in the world, affecting approximately one per cent of adults older than 60 (Samii, 2004). However, of the 10,000 people diagnosed each year in the UK, one in 20 will be aged under 40 years.
- The exact causes are unknown.Nerve cells decrease in the substantia nigra - the part of the brain that makes dopamine, which facilitates coordinated function of the body's muscles and movement. The chemical in the synapse that breaks down the dopamine depletes what little dopamine is left.
- The result is uncoordinated movement, resulting in tremor, stiff muscles and joints and problems with mobility.
- Research suggests that people who experience severe head injuries can face an increased risk of developing Parkinson's disease (Bower et al, 2003) and there has been research into a genetic link (Chase, 1997).
- There are three main symptoms:
- Tremor - usually begins down one side in the hand or arm and is more likely to occur when the part of the body affected is at rest. It often becomes more pronounced when the person becomes anxious or excited.
- Muscular rigidity - a common symptom in those who are undiagnosed. People may experience problems turning round, getting out of a chair, or making fine finger movements. Some people become stooped and facial muscles stiffen. There is often associated pain.
- Bradykinesia - people with Parkinson's disease often find that initiating movement becomes more difficult or that it takes longer to perform movements. Lack of coordination when moving can also be present.
- Further symptoms may also include tiredness, depression, and difficulties with communication, such as speech and facial expression. Balance can also be affected.
- There are no definitive tests for the disease. Diagnosis is based on medical history and clinical examination of the symptoms.
- The neurons affected by the disease have a limited capacity for repair and there is no current treatment that can halt its progress. Treatment focuses on symptom control and is patient-specific, depending on age, stage of disease and symptom severity.
- Medication commonly used includes levodopa, which is modified by the brain to produce dopamine, and anticholinergics, to help with tremor and rigidity.
- Surgical options include:
- Deep brain stimulation, in which electrodes are implanted inside the brain. These stimulate the deep brain nuclei, improving tremor and stiffness, and can be switched off when not required.
- Pallidotomy, which involves scarring a tiny part of the globus pallidus in the brain. This reduces the brain activity in that area, which can help to relieve movement symptoms such as tremor and rigidity.
- Research continues into 'restorative' therapies, such as stem cells.