Understanding Parkinson's Disease - Diagnosis and Treatment

How Is Parkinson's Disease Diagnosed?

Usually, the outward symptoms of Parkinson's are distinctive enough for a diagnosis to be made. Tests can help your doctor determine whether you have Parkinson's disease or some other type of parkinsonism. If you don't have a response to the drugs used to treat Parkinson's disease, your doctor will probably continue to search for the cause of your parkinsonism.

What Are the Treatments for Parkinson’s Disease?

Most Parkinson’s disease treatments aim at restoring the proper balance of the neurotransmitters acetylcholine and dopamine by increasing dopamine levels. Drugs are the standard way of doing this, but neurosurgeons have had some success with experiments involving surgery. If your symptoms are not due to Parkinson's disease, your doctor will select the appropriate treatment for the underlying cause.

Conventional Medicine for Parkinson's Disease

Symptoms of Parkinson’s disease can be effectively controlled for years with medication.

Levodopa – also called L-dopa – is the drug most often prescribed. The body metabolizes it to produce dopamine. (Direct administration of dopamine is ineffective, though; the brain's natural protections block its uptake.) To suppress nausea and other possible side effects, levodopa is often used in conjunction with a related drug called carbidopa.

But some patients cannot tolerate carbidopa and so take levodopa alone. If you take only levodopa, it's important not to take it at the same time as food or vitamins containing vitamin B-6, which interferes with its effectiveness.

Most doctors try to postpone starting patients on levodopa as long as possible, because the medication tends to lose effectiveness over time. However, there is some controversy about waiting to begin treatment with levodopa because it can be so beneficial. Researchers have thus investigated ways to offset the loss of effectiveness.

COMT inhibitors such as tolcapone (Tasmar) and entacapone (Comtan) are drugs that are taken with levodopa. They prolong the duration of symptom relief by blocking the action of an enzyme that breaks down levodopa.

Stalevo is a newer combination tablet that combines carbidopa/levodopa, with entacapone. While carbidopa reduces the side effects of levodopa, entacapone extends the time levodopa is active in the brain.

Dopamine agonists are dopamine-like drugs that directly imitate dopamine's activity in the brain. Pramipexole and ropinirole) used alone or in combination with L-dopa are effective in treating the motor symptoms of Parkinson's disease.

Other medications prescribed for Parkinson's disease include apomorphine, benztropine, amantadine, selegiline and anticholinergic drugs; all can help control various symptoms -- in some cases by releasing dopamine from nerve cells, in others by reducing the effects of acetylcholine, rather than increasing the amount of dopamine.

Other Types of Treatment for Parkinson’s Disease

Neurologists and neurosurgeons have explored various ways of grafting dopamine-producing cells in the brain of those with Parkinson’s disease, rather than trying to correct the neurotransmitter imbalance with drugs. One promising approach uses fetal-tissue implants. Some improvements have been observed, but because of the source of the cells, the technique is highly controversial. Alternative dopamine-producing cell lines are being developed.