How is Parkinson's Diagnosed?
There are no blood or laboratory tests to diagnose Parkinson's disease. Diagnosis is based on medical history and a neurological examination. In some cases, early diagnosis is difficult because the symptoms may be considered as those of normal aging. Also, MRI or CT brain scans of people with Parkinson's usually appear normal. Since other diseases have similar features but require different treatments, making a diagnosis is important for properly treating Parkinson's.
With medications, most people with Parkinson's can live productive lives for many years after diagnosis.
How is the Disease Treated?
At present, there is no cure for Parkinson's. Medications can often lessen its symptoms for several years. In later stages of the disease, surgery may be considered. A doctor will assess how the symptoms disrupt the person's life, then tailor treatment to the person's particular condition. Since no two people react the same way to a given drug, it may take time and patience to get the dose just right. Even then, symptoms may not be completely alleviated.
There are three categories of Parkinson's medications. The first includes drugs that increase dopamine in the brain. The most common is levodopa (L-dopa, for short). Others mimic dopamine or prevent or slow its breakdown. The second set of drugs eases some of Parkinson's movement symptoms, such as tremor. The third helps to control non-motor symptoms, including depression.
- Levodopa. L-dopa is the cornerstone of Parkinson's drug therapy. It helps replenish the brain's supply of dopamine, reducing the tremors and other motor symptoms of Parkinson's. It typically helps most with bradykinesia and rigidity, but not balance problems. L-dopa usually is combined with the drug carbidopa to diminish nausea, vomiting, and other side effects. Although there is often noticeable improvement after starting L-dopa, people typically need to gradually increase the dose for maximum benefit.
- L-dopa does not stop Parkinson's from progressing and is not a cure. Over long periods people commonly develop involuntary twisting and writhing (called dyskinesias). Although L-dopa can be reduced, doctors and patients must work together closely to find a tolerable balance between L-dopa's benefits and side effects. Surgery may be considered for severe dyskinesias. Because dyskinesias tend to be associated with long-term L-dopa use, doctors often start patients on other dopamine-increasing drugs and add L-dopa later.
- In late Parkinson's, before the first dose of L-dopa in the morning and between the day's subsequent doses, symptoms may become more pronounced because the drug's effectiveness wears off. People may also experience sudden, unpredictable "off periods." One approach then is to take more frequent, smaller amounts of L-dopa. Patients should never stop taking L-dopa without consulting their doctor. Rapid withdrawal can have serious side effects.
- Dopamine agonists. These drugs include apomorphine, pramipexole, ropinirole, and rotigotine. They mimic dopamine in the brain and can be given alone or with L-dopa.
- MAO-B inhibitors. These drugs cause dopamine to accumulate in surviving nerve cells and reduce the symptoms of Parkinson's. They include selegiline (also called deprenyl) and rasagiline.
- COMT inhibitors. These drugs prolong L-dopa's effects by preventing the breakdown of dopamine. They include entacapone and tolcapone.
- Amantadine. An antiviral drug, amantadine, can help reduce symptoms and dyskinesia. It is often used alone in Parkinson's early stages.
- Anticholinergics. These drugs include trihexyphenidyl, benztropine, and ethopropazine. They can be particularly effective for tremor.
Medications for Non-Motor Symptoms. Doctors also may prescribe a variety of medications to treat such non-motor Parkinson's symptoms as depression and anxiety.
Before L-dopa, surgery was a common option for alleviating Parkinson's symptoms. Today, deep brain stimulation (DBS) is a common surgical treatment. It is approved by the U.S. Food and Drug Administration and widely used.
Deep brain stimulation. In DBS, an electrode is surgically implanted into part of the brain. It stimulates the brain to help block Parkinson's motor symptoms. People who initially respond well to L-dopa tend to respond well to DBS. While benefits on motor function benefits can be substantial, DBS usually does not help with speech problems, "freezing," posture, balance, anxiety, depression, or dementia.
Also, DBS does not stop Parkinson's from progressing, and some problems may gradually return. It is not generally an option for people with memory problems, hallucinations, severe depression, poor health, or a poor response to L-dopa. As with any brain surgery, there are potential complications, including stroke or brain hemorrhage. These are rare, however. There is also a risk of infection.
Researchers continue to study how best to improve DBS, its technology, the best part of the brain to receive stimulation, and the long-term effects.
Complementary and Supportive Therapies
A wide variety of complementary and supportive therapies may be used for Parkinson's. Among them are standard physical, occupational, and speech therapies, which can help with such problems as walking and voice disorders, tremors and rigidity, and cognitive decline. Other supportive methods include:
Diet. There currently are no specific vitamins, minerals, or other nutrients of proven therapeutic value in Parkinson's. While there is no proof that any specific dietary factor is beneficial, a normal, healthy diet can promote overall well being for people with Parkinson's, just as it would for anyone else. For example, a fiber-rich diet and drinking plenty of fluids can help alleviate constipation.
Exercise. Exercise's effects on Parkinson's are not known, but it may improve body strength so that the person is less disabled. Exercises also improve balance, helping people minimize gait problems, and can strengthen certain muscles so that people can speak and swallow better. Walking, gardening, swimming, calisthenics, and other general physical activity improve emotional wellbeing. Parkinson's patients should always check with their doctors before beginning a new exercise program.
Other complementary therapies for Parkinson's include massage, yoga, tai chi, hypnosis, acupuncture, and the Alexander technique, which optimizes posture and muscle activity. Another important approach involves speech and swallowing evaluation and therapy. Certain techniques can help with the low voice volume that Parkinson's patients often experience.