How is PD treated?

Parkinson's disease is a chronic disorder that requires broad-based management including patient and family education, support group services, general wellness maintenance, exercise, and nutrition.

At present, there is no cure for PD, but medications or surgery can provide relief from the symptoms.

Levodopa

The most widely used form of treatment is L-dopa in various forms.

Dopamine agonists

The dopamine-agonists bromocriptine, pergolide, pramipexole, ropinirole , cabergoline, apomorphine, and lisuride, are moderately effective. These have their own side effects including those listed above in addition to somnolence, hallucinations and /or insomnia. Several forms of dopamine agonism have been linked with a markedly increased risk of problem gambling. Dopamine agonists initially act by stimulating some of the dopamine receptors. However, they cause the dopamine receptors to become progressively less sensitive, thereby eventually increasing the symptoms.

MAO-B inhibitors

Selegiline and rasagiline reduce the symptoms by inhibiting monoamine oxidase-B (MAO-B), which inhibits the breakdown of dopamine secreted by the dopaminergic neurons.

Surgery

Treating Parkinson's disease with surgery was once a common practice. But after the discovery of levodopa, surgery was restricted to only a few cases. Studies in the past few decades have led to great improvements in surgical techniques, and surgery is again being used in people with advanced PD for whom drug therapy is no longer sufficient. Deep brain stimulation is presently the most used surgical means of treatment, but other surgical therapies that have shown promise include surgical lesion of the subthalamic nucleus and of the internal segment of the globus pallidus, a procedure known as pallidotomy.

Speech therapies

The most widely practiced treatment for the speech disorders associated with Parkinson's disease is Lee Silverman Voice Treatment (LSVT). LSVT focuses on increasing vocal loudness.
A study found that an electronic device providing frequency-shifted auditory feedback (FAF) improved the clarity of Parkinson's patients' speech.

Physical exercise

Regular physical exercise and/or therapy, including in forms such as yoga, tai chi, and dance can be beneficial to the patient for maintaining and improving mobility, flexibility, balance and a range of motion. Physicians and physical therapists often recommend basic exercises, such as bringing the toes up with every step, carrying a bag with weight to decrease the bend having on one side, and practicing chewing hard and move the food around the mouth.

Methods undergoing evaluation

Gene therapy
Currently under investigation is gene therapy. This involves using a harmless virus to shuttle a gene into a part of the brain called the subthalamic nucleus (STN). The gene used leads to the production of an enzyme
Implantation of stem cells genetically engineered to produce dopamine or stem cells that transform into dopamine-producing cells has already started being used. These could not constitute cures because they do not address the considerable loss of activity of the dopaminergic neurons. Initial results have been unsatifactory, with patients still retaining their drugs and symptoms.
Neuroprotective treatments
Neuroprotective treatments are at the forefront of PD research, but are still under clinical scrutiny. These agents could protect neurons from cell death induced by disease presence resulting in a slower pregression of disease.
Neural transplantation
The first trial of dopaminergic transplants failed to show an improvement in quality of life although some significant clinical improvements were seen in patients below the age of 60.
Nutrients
Nutrients have been used in clinical studies and are widely used by people with Parkinson's disease in order to partially treat PD or slow down its deterioration. The L-dopa precursor L-tyrosine was shown to relieve an average of 70% of symptoms. Ferrous iron, the essential cofactor for L-dopa biosynthesis was shown to relieve between 10% and 60% of symptoms in 110 out of 110 patients.
Vitamin C and vitamin E in large doses are commonly used by patients in order to theoretically lessen the cell damage that occurs in Parkinson's disease.
Coenzyme Q10 has more recently been used for similar reasons. MitoQ is a newly developed synthetic substance that is similar in structure and function to coenzyme Q10. However, proof of benefit has not been demonstrated yet.
Qigong
There have been two studies looking at qigong in Parkinson's disease. In a trial in Bonn, an open-label randomised pilot study in 56 patients found an improvement in motor and non-motor symptoms amongst patients who had undergone one hour of structured Qigong exercise per week in two 8-week blocks. The authors speculate that visualizing the flow of "energy" might act as an internal cue and so help improve movement.

The second study, however, found Qigong to be ineffective in treating Parkinson's disease. In that study, researchers used a randomized cross-over trial to compare aerobic training with Qigong in advanced Parkinson's disease. Two groups of PD patients were assessed, had 20 sessions of either aerobic exercise or qigong, were assessed again, then after a 2 month gap were switched over for another 20 sessions, and finally assessed again. The authors found an improvement in motor ability and cardiorespiratory function following aerobic exercise, but found no benefit following Qigong. The authors also point out that aerobic exercise had no benefit for patients' quality of life.
Botox
Recently, Botox injections are being investigated as a non-FDA approved possible experimental treatment.