Parkinson's disease is a complex condition with a wide range of symptoms. There is currently no cure, but treatment can help relieve symptoms, slow disease progression, and improve quality of life.
Treatment approaches include medication, surgery, alternative and complementary therapies, occupational therapy, and speech therapy.
The symptoms of Parkinson's disease (PD) vary widely so no single treatment will work for everyone with this condition.
The National Institutes of Health note that there are three types of drug available to treat PD:
- medications that raise dopamine levels in the brain, such as levodopa (also known as L-dopa), and drugs that mimic dopamine or stop it from breaking down
- drugs that reduce or relieve tremor, or shaking, and other symptoms affecting body movements
- medication for depression, psychosis, dementia, and other non-motor symptoms
Increasing dopamine levels
The symptoms of PD are mainly due to low levels of dopamine in the brain. Dopamine is a chemical messenger, or neurotransmitter. Most drugs for the condition aim to either replenish dopamine levels or mimic its action. These are called dopaminergic drugs.
Dopaminergic medications can:
- reduce rigidity and muscle stiffness
- improve the speed of movement
- help with coordination
- lessen tremor
Taking dopamine itself does not help because it cannot enter the brain, but drugs that enable the brain to create dopamine can be beneficial.
Doctors may prescribe the following medications for people with PD:
Levodopa is the most effective medication for PD. Nerve cells in the brain absorb the drug and turn it into dopamine.
The person will take levodopa orally in either tablet or liquid form.
Its side effects include:
This combination drug, which is available under the brand name Sinemet, contains both carbidopa and levodopa.
Carbidopa prevents the destruction of levodopa by enzymes in the digestive tract and reduces some of its side effects, including nausea.
As Parkinson's disease progresses, long-term treatment with levodopa may become less effective.
The person's response to the drug may begin to fluctuate, and they might experience "off" times between doses, during which movement can be more challenging.
The doctor may have to change the dosage by amending the size or frequency of the doses. However, the individual will need to continue using the drug because stopping it suddenly can result in withdrawal symptoms.
The side effects of this combination drug may include:
- mental disturbances, such as confusion, delusions, and hallucinations
- involuntary movements, such as jerking or twisting
People taking this drug may also have a higher risk of liver, kidney, and cardiovascular problems and be more likely to develop glaucoma.
The long-term use of levodopa, either alone or in combination with carbidopa, increases the risk of:
- fluctuating motor responses
- uncontrolled, involuntary movements known as dyskinesia
For this reason, a doctor may prescribe a dopamine agonist instead.
These drugs mimic the effects of dopamine in the brain. The neurons react to them as they would to dopamine.
Dopamine agonists can be a good alternative to levodopa as they have a lower risk of long-term complications.
However, they can have similar side effects to carbidopa-levodopa.
The side effects may include:
- mental confusion
- low blood pressure
- muscle cramps
Dopamine agonists may not be suitable for people with a history of cardiovascular disease, depression, or psychosis.
A doctor usually prescribes these medications in tablet form, but they are also available as an injection or a skin patch.
Monoamine oxidase-B inhibitors (MAO-B inhibitors)
MAO-B inhibitors are another alternative to levodopa. Examples include selegiline and rasagiline.
These drugs work by blocking the effects of an enzyme called monoamine oxidase-B (MAO-B), which destroys dopamine in the brain. Blocking MAO-B allows the dopamine to last for longer in this organ.
MAO-B inhibitors have a less significant effect than levodopa, but it is possible to take them together with levodopa or dopamine agonists.
There is a risk that MAO-B inhibitors will have adverse interactions with some depression medications and certain narcotics. They also have some side effects, including:
Catechol O-methyltransferase (COMT) inhibitors
This type of medication blocks COMT, an enzyme that breaks down levodopa. By doing this, it can prolong the effect of carbidopa-levodopa therapy.
These medications control tremor. Examples include trihexyphenidyl (Artane) and benztropine (Cogentin).
However, some people prefer not to use these drugs because of the side effects, which can include:
Depression, psychosis, and dementia
Depression is a common problem for people with PD.
The American Academy of Neurology (AAN) recommend amitriptyline for treating depression, stating that there is currently insufficient evidence to support the use of other treatments.
Psychosis can also occur, and this becomes more severe as the disease progresses. Clozapine (Clozaril) can treat psychosis, but doctors should monitor the person carefully as this medication can have severe adverse effects.
Dementia develops over time in many people with PD, especially if they have PD with Lewy bodies.
Lewy bodies are abnormal deposits in the brain. Rivastigmine (Exelon) is a treatment option for dementia, but the AAN point out that the benefits can be small, and it may make tremors worse. Donepezil (Aricept) is another option.
Treatment for PD may also involve speech and occupational therapy.
Speech therapy: PD can cause a person to have slurred speech and abnormal body language. It can also be difficult for a person with PD to swallow.
A speech and language therapist can provide muscle-training techniques that help people overcome some of the common problems relating to speech and swallowing.
Occupational therapy: An occupational therapist can pinpoint everyday tasks that PD can make problematic, and they can help find practical solutions.
Examples include helping people with techniques for getting dressed, preparing meals, performing household chores, and doing the shopping.
This procedure can treat many of the symptoms that make it hard for a person with PD to function, such as tremor, rigidity, stiffness, slowed movement, and walking difficulties.
A doctor will implant an electrode inside a part of the brain that controls movement. The electrode will provide stimulation to the brain.
Next, they will place a pacemaker-like device, or neurostimulator, under the skin in the upper chest. This device will control the amount of stimulation that the electrode delivers.
A wire travels under the skin and connects the neurostimulator to the electrode.
The neurostimulator sends electrical impulses along the wire and into the brain via the electrode.
These impulses prevent symptoms by interfering with the electrical signals that cause them.
Doctors typically use deep brain stimulation during the later stages of PD, when medications become less effective.
The risks of this procedure include brain hemorrhage and infection. People who do not respond to carbidopa-levodopa therapy will not benefit from deep brain stimulation.
This is a type of surgery that was common in the past but is rare nowadays.
The surgeon uses a local anesthetic to numb the area. They then make a small hole in the skull, insert a hollow tube, and use liquid nitrogen to destroy the thalamus, a tiny part of the brain that is responsible for the tremor.
The surgeon will operate on the side of the head opposite to the affected side of the body. If a person has a tremor in their right hand, for example, the surgery will take place on the left side. It is possible to operate on both sides, but this can lead to other problems.
A thalamotomy may help if a person has a severe tremor on one side, but it does not relieve slow movement, walking difficulties, speech problems, or other symptoms.
Many people with PD experience fluctuations in blood pressure. Low blood pressure is common, especially when standing up or changing position.
Some medications can help stabilize blood pressure.
Other tips that may help include:
- avoiding caffeinated products in the evening
- eating several small meals a day
- abstaining from alcohol
People have tried a wide range of complementary therapies for PD, and there is anecdotal evidence that these can help with relaxation and reduce stress and depression. However, there is little scientific proof to support these claims.
Alternative therapies that may be beneficial include:
- tai chi
- chiropractic manipulation
- herbal remedies
- the Alexander Technique, which can help with posture and muscle activity
However, more research is necessary to confirm the effectiveness of these treatments.
Some people believe that supplements can benefit people with PD, but there is limited research to support their effectiveness.
Proponents recommend the following supplements:
Velvet bean: Also known as Mucuna pruriens, this supplement contains levodopa, but it is not clear if it has any effect as a PD treatment.
Vitamin C: There is some evidence that vitamin C can increase levodopa levels, but researchers have not yet confirmed that it can help people with PD.
Folic acid: This may help, but more research is necessary.
Vitamin E: Some people recommend vitamin E supplements, but the AAN state that they are ineffective as a treatment for PD.
Anyone who is considering using herbal remedies or supplements should speak with their doctor first, because some may interact with PD medications or make symptoms worse.
There is no evidence that any specific diet will help people with PD, but a healthful diet comprising plenty of fresh fruit and vegetables will enhance a person's overall health.
A high-fiber diet and adequate fluid consumption can help reduce constipation, which is a common problem with PD.
Weight loss can often occur too. A dietitian should be able to offer advice on how to prevent this.
Exactly how exercise can help a person with PD is unclear, but animal studies have suggested that it may offer some neuroprotection.
Moderate activities, such as walking, gardening, and swimming, are suitable for many people. They can often improve emotional well-being too, especially if the individual can do them with a friend, family member, or another person in the community.
It is essential that people with PD speak to their doctor before making any changes to their level of exercise.
Parkinson's disease affects individuals in different ways, and a doctor will prescribe or recommend appropriate therapies to relieve the symptoms.
These include a range of medications, lifestyle changes, and other interventions.
It can take time to get the treatment right, and symptoms can also change over time. Staying in touch with the doctor is important for maintaining a suitable treatment regime.
This, in turn can improve the quality of life of a person with PD and their loved ones.