There is currently (April, 2010) no cure for Parkinson’s disease. Therapy focuses on treating the symptoms that undermine the patient’s quality of life. As people have enormously varying symptoms and levels of severity, there is no standard or best treatment that applies to everybody.
Treatment approaches include medication, surgery, general lifestyle modifications (rest and exercise), physical therapy (UK: Physiotherapy), support groups, occupational therapy and speech therapy.
Medication - as most Parkinson’s symptoms are caused by low levels of dopamine in the brain, most drugs are aimed at either replenishing dopamine levels, or mimicking its action - dopaminergic drugs do this. Dopaminergic medications reduce rigidity (muscle stiffness), improve speed, help with coordination, and lessen tremor (shaking). Taking dopamine itself does not help, because it cannot enter the brain.
Levodopa - the most effective Parkinson’s drug; is absorbed by the nerve cells in the brain and turned into dopamine. It is taken orally, in tablet or liquid form. Levodopa is combined with carbidopa to create Sinemet, a combination drug. Carbidopa prevents the levodopa from being destroyed by enzymes in the digestive tract; it also reduces levodopa side effects, such as nausea, vomiting, fatigue and dizziness. In the UK and the rest of Europe benserazide may be combined with levodopa (Madopar).
As Parkinson’s disease progresses the effects of levodopa may wear off and the doctor may have to increase the dosage. Increased dosage also raises the risk of developing side effects, which may include confusion, delusions, hallucinations, compulsive behavior, and dyskinesia (involuntary movements). Reducing the dosage will usually help with side effects, but with the risk that parkinsonism increases.
Dopamine agonists - these drugs mimic the effects of dopamine in the brain. The neurons react as they would to dopamine. Although not as effective as levodopa, dopamine agonists last longer and help reduce the waning effect of levodopa. They are usually prescribed in tablet form, but may also be taken by injection, or as a skin-patch. Examples include pramipexole (Mirapex), ropinirole (Requip), rotigotine (Neupro), and apomorphine (Apokyn).
Side effects are similar to those of carbidopa-levodopa. The risk of developing compulsive behaviors, such as compulsive gambling and hypersexuality are greater.
Monoamine oxidase-B inhibitors (MAO B inhibitors) - an alternative to levodopa. Examples include selegiline and rasagiline. MAO B inhibitors work by blocking the effects of monoamine oxidase-B (MAO B) in the brain. Monoamine oxidase-B destroys dopamine - by blocking MAO B the dopamine can last longer in the brain. MAO B inhibitors have a smaller effect than levodopa. MAO B inhibitors can be used in combination with levodopa or dopamine agonists. There is a risk of serious interactions with some medications used for treating depression, as well as some narcotics.
Side effects of selegiline may include:
- Dry mouth
- Stomach pain
- Strange and/or vivid dreams
Side effects of rasagiline may include:
- Fever, with joint and muscle aches (flu-like)
- Neck pain
- Runny nose
- Stomach pain
- COMT (catechol O-methyltransferase) inhibitors - this medication blocks the enzyme that breaks down levodopa, hence prolonging the effect of carbidopa-levodopa therapy.
- Anticholinergics - used for controlling tremor (shaking). Examples include trihexyphenidyl and benztropine (Cogentin). Some patients may find that the side effects are much greater than the slight benefits. Side effects may include urine retention, severe constipation, nausea and dry mouth. Male patients with an enlarged prostate have a higher risk of developing urine retention.
- Antivirals - may be used on its own during early-stage Parkinson’s disease. May also be used alongside carbidopa-levodopa therapy later on. Side effects include ankle edema (swelling) and skin discoloration. An example of this drug is amantadine (Symmetrel).
Exercise and Physical Therapy - exercise is crucial for maintaining function. Physical therapy can help the patient improve mobility, range of motion, as well as muscle tone. Physical therapy cannot stop the progression of Parkinson’s disease, but it can help the patient cope and feel better. The physical therapist can help relieve muscle stiffness and joint pain through movement and exercise. A qualified physical therapist (UK: physiotherapist) can help the patient improve balance and gait.
Using the treadmill, resistance training and stretching can provide Parkinson’s patients with significant benefits. A study published in Archives of Neurology (November 2012) reported that exercise improves gait speed, overall fitness and muscle strength.
Hard and fast cycling can benefit Parkinson’s patients, researchers from the Cleveland Clinic Lerner Research Institute explained at the Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, Chicago (November 2012). The scientists added that the activity appears to make parts of the brain that deal with movement connect to each other better.
- Speech therapy - according to the National Health Service (NHS), UK, approximately half of all Parkinson’s patients experience communication problems, such as slurred speech and poor body language. A speech and language therapist can help with the use of language and speech. Patients with swallowing difficulties may also be helped by a speech therapist.
- Occupational therapy - an occupational therapist can pinpoint everyday life problems and help work out practical solutions. Examples include getting dressed, or getting the shopping done.
Deep brain stimulation - a surgical procedure used to treat several disabling neurological symptoms, such as tremor, rigidity, stiffness, slowed movement and walking difficulties.
An electrode is implanted deep inside the brain, where movement is controlled. A pacemaker-like device (neurostimulator), which controls the amount of stimulation delivered by the electrode, is placed under the skin in the upper chest. A wire travels under the skin and connects the neurostimulator to the electrode.
Electrical impulses are sent from the neurostimulator, along the wire, and into the brain via the electrode. They interfere with the electrical signals that cause symptoms, effectively blocking them.
Deep brain stimulation is generally used when the patient is in the advance stages of Parkinson’s disease, and has unstable medication responses.
The procedure has some risks, including brain hemorrhage and infection. Patients who do not respond to carbidopa-levodopa therapy do not benefit from deep brain stimulation.
- Thalamotomy - the thalamus is destroyed (lesioned) or removed by cutting (ablated). The thalamus is a tiny part of the brain. The proecedure may help reduce tremor. Thalamotomy is rarely performed these days. It may be used for patients with tremor who have not responded to medication. The procedure does not improve slow movement, walking difficulties or speech problems.
- Pallidotomy - since the introduction of deep brain stimulation, this procedure is rarely done. The gobus pallidus, a part of the brain, may be overactive in patients with Parkinson’s disease, causing a different part of the brain which controls movement to become less active. The surgeon destroys a small part of the globus pallidus by creating a scar, resulting in less activity in that area of the brain, which in turn may help relieve movement symptoms, such as rigidity and tremor.
- Subthalamotomy - rarely performed these days. The subthalamus, a very small area of the brain, is destroyed.
Alternative therapies - according to the National Health Service (NHS), UK, up to 40% of patients with Parkinson’s disease in the UK use some type of alternative therapy, such as massage, acupuncture or herbal remedies. Patients using herbal remedies and/or supplements should tell their doctor - some may interact with Parkinson’s medications.
Nutrition - some patients with Parkinson’s disease suffer from constipation. A diet high in fiber, as well as adequate fluid consumption is important for reducing the number of incidences as well as severity of constipation.
Postural (Orthostatic) Hypotension
Postural (orthostatic) hypotension - low blood pressure when changing position - is another problem experienced by some Parkinson’s disease patients. Doctors may advise an increase in salt and fluid intake, as well as avoiding products with caffeine in the evening, eating many small meals a day, and abstaining from alcoholic drinks.
If the patient loses weight - a common problem with Parkinson’s disease - he/she may be referred to a dietitian.