Treatment
Treatment involves the use of drugs, physical therapies and occasionally surgery.
Treatment should be started when the symptoms start to cause disability.
Drug therapy
The most commonly used drug is levodopa (Sinemet and Madopar, which contain levodopa and an enzyme blocker to prevent the dopa from being consumed in the body before getting into the brain), which increases dopamine levels in the brain.
Levodopa is usually the drug of first choice in the elderly. However, in younger people, other drugs may be used to delay the need to treat with levodopa. Potential alternatives include dopamine agonists, monoamine oxidase B inhibitors, amantadine and anticholinergics.
As the disease progresses however, most people eventually require treatment with levodopa.
The main problem with levodopa is that prolonged use is associated with motor fluctuations. When motor fluctuations occur, people initially may find that the effects of their regular dose do not seem to last until the next dose is due (end of dose deterioration or early wearing-off). As the disease progresses, people may find that their symptoms can re-appear quickly and unexpectedly, a sensation that some have described as being like a light switch being turned on and off (on-off syndrome). Some people find that they start to develop involuntary fidgety movements (dyskinesias), which occur initially when the level of levodopa in the bloodstream is at its peak, but may appear at any time later on.
Several drugs are available to treat motor fluctuations. They include dopamine agonists; monoamine oxidase B inhibitors; amantadine (reduces dyskinesias), apomorphine (reduce off periods and fluctuations) and Catechol - O - methyl transferase (COMT) inhibitors (Entacapone and Tolcapone reduce wearing off and fluctuations).
Significant depressive illness is usually treated with SSRI antidepressants, as tricyclic antidepressants may interfere with the absorption of medication from the bowel.
Physical therapy
This attempts to maximise activity and may include:
Physiotherapy for gait re-education, improvement of balance and flexibility; enhancement of aerobic capability; improvement of movement initiation; improvement of functional independence including mobility and activities of daily living and provision of advice regarding safety in the home environment.
Physiotherapy can teach various ‘trick’ strategies to overcome the problem of initiation of movement and freezing. For example, rising from a chair can be difficult and the person can be taught to rock backwards and forwards until there is sufficient momentum to get up. Freezing can sometimes be helped by getting the person to pretend that they have to step over a small obstacle. Muscle rigidity can be uncomfortable and stretching exercises are often helpful. Physiotherapy is unlikely to help bradykinesia and rigidity but physiotherapy has a psychological benefit.
Occupational therapy directed towards maintenance of work and family roles, employment, home care and leisure; improvement in mobility and ability to transfer; improvement of personal self care activities such as eating, drinking, washing and dressing; environmental issues to improve safety and motor function and cognitive assessment and appropriate intervention.
Occupational therapy can improve function by the prescription of suitable aids, for example, large handled cutlery, plate guards and use of velcro instead of buttons.
Speech and language therapy for improvement of vocal loudness and pitch range; strategies to optimise speech intelligibility ensuring effective communication is maintained during the course of disease to include the use of assistive technology; support and improve swallowing and minimise the risk of aspiration and malnutrition.
Treatment of postural hypotension is difficult. In mild cases advice such as avoiding rapid changes of posture, large meals, excessive alcohol, warm temperatures and excessive straining may suffice. In more severe cases elastic stockings may be prescribed but are usually of little benefit. Fludrocortisone may be prescribed but is also of limited benefit.
Treatment of sleep disturbance may include use of devices to help turn over in the bed, such as a strap on the bed head to hold on to or cotton bed socks to enable the person to push on the bed sheet. Night sedation should be avoided as this can increase daytime sleepiness.
Erectile failure can respond to Sildenafil (Viagra) and similar drugs.
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Deep Brain Stimulation (DBS)
The usual surgical treatment of first choice is Deep Brain Stimulation.
This involves implantation of a wire into one of three target sites in the brain – the subthalamic nuclei (sub-thalamic stimulation): the globus pallidus (pallidal stimulation) or the thalamus (thalamic stimulation). The wire is usually implanted under local anaesthetic and the wire is attached to an Implantable Pulse Generator (IPG), which is implanted under the skin under local anaesthetic. The IPG is programmed by a computer but can usually be switched on and off by the person using a hand held programmer or magnet.
Sub-thalamic stimulation is now favoured by most centres.
Sub-thalamic stimulation benefits 70-80% of people. It can have a major effect on tremor, bradykinesia and rigidity. It can also have a positive effect on postural stability, gait and freezing. Most people who have had subthalamic stimulation have been able to substantially reduce their dose of levodopa, which in turn leads to a reduction in levodopa induced dyskinesias and improvement in the on off syndrome.
Pallidal stimulation is used to treat levodopa induced involuntary movements (dyskinesia). It can have variable effects on dyskinesias and usually helps rigidity and reduces the on off syndrome. About 70-80% of people derive some benefit. It may not help bradykinesia and can sometimes worsen it.
Thalamic stimulation is used to treat tremor that is not controlled effectively by medication. It results in a reduction or complete suppression of tremor in about 80 percent of people. However, some people derive no benefit and occasionally the tremor reappears. It is not known whether the effects of thalamic stimulation are permanent. Follow up over 10 years suggests that control of the tremor is maintained, but bradykinesia and dyskinesia do deteriorate as thalamic stimulation is not effective at controlling these symptoms. Most centres have now abandoned its use in favour of pallidal and sub-thalamic stimulation.
Most surgeons would not perform DBS on people who have cognitive involvement, who are confused, psychotic or experiencing severe depression.
Other surgical techniques
In certain people, lesioning (surgically-induced damage to specific areas of the brain) may be considered. There are two options - Thalamotomy involves damaging part of the thalamus on one side only and is mainly now used for drug resistant tremor; Pallidotomy involves damaging part of the globus pallidus, and can have a dramatic effect on rigidity, akinesia and dyskinesia. However lesioning is unlikely to continue as a treatment option as it is irreversible.
Other techniques that include infusion of chemicals into the affected areas, implantation of foetal brain tissue and “gamma knife” surgery, are largely experimental and not in general use.
Amended April 2008
