Parkinson's disease is a progressive nervous system disorder that affects how the person speaks and writes including how they move. Symptoms develop and may start off with ever-so-slight tremors in one hand. People with this disease find that they cannot carry out movements as rapidly as before and also experience stiffness and this is called bradykinesia. The muscles of a person with this become weaker and the individual may assume an unusual posture.
It belongs to a group of conditions called movement disorders. It describes a variety of abnormal body movements that have a neurological basis, and include conditions such as ataxia, cerebral palsy, and Tourette syndrome. Apart from slow movements and tremor, the patient may also have a fixed, inexpressive face - this is because of poorer control over facial muscle coordination and movement. It also affects the voice and sense of smell.
Parkinson's disease is caused by the destruction or damaging of dopamine-producing nerve cells called dopaminergic cells. These cells in turn make it harder for the brain to control and coordinate movement of the muscle. Experts are not sure why the nerve cells that cause it become damaged or die.
• Adykinesia (slowed motion, slowness of movement)
• Resting tremor (shaking)
• Rigidity (muscle stiffness)
• Posture and balance
As most the Parkinson's symptoms are caused by low levels of dopamine in the brain, most drugs are intended at either restoring dopamine levels, or mimicking its action - dopaminergic drugs do this. These medications improve speed, reduce rigidity (muscle stiffness), help with coordination, and lessen tremor (shaking). Dopamine cannot enter the brain, so taking it alone does not help.
• Levodopa - It is the most effective Parkinson's drug. It is turned into dopamine after being absorbed by the nerve cells in the brain. It is taken orally, liquid or tablet form.
• Dopamine agonists - these drugs mimic the effects of dopamine in the brain. The neurons react in the same way as they would react to dopamine. Although it is not as effective as levodopa, it helps reduce the waning effect of levodopa and lasts longer.
They are usually prescribed in tablet form, but may also be taken as a skin-patch or by injection.
• Monoamine oxidase-B inhibitors (MAO B inhibitors) - It is an alternative to levodopa.
• Compulsive behaviour
• Dyskinesia (involuntary movements)