Parkinson’s disease is associated with a gradual loss of cells in the substantia nigra, which produces dopamine. Dopamine is a chemical messenger that transmits a signal between two regions of the brain, the substantia nigra and the corpus striatum to regulate muscle activity. Insufficient dopamine in the striatum causes the nerve cells in this region to “fire” out of control leaving the individual unable to direct or control movements in a normal manner. This is thought to lead to the initial symptoms of Parkinson’s disease. Later in the disease, other areas of the brain and nervous system degenerate.

The exact cause for the loss of cells is unknown. Possible causes currently being researched are:

• Genetic predisposition: The inheritance of a gene passed down from a previous generation
• Free radicals are unstable molecules produced during normal chemical reactions in the body. When these molecules interact with other molecules they have the ability to damage a variety of tissue types, including neurons.
• Environmental toxins: This has been seen in people who took an illegal drug contaminated with a chemical called, MPTP. These individuals developed severe Parkinson-like symptoms. This also occurred in the early 1900′s in individuals who had suffered from a severe form of influenza.
• Accelerated aging: As a person ages, there is a normal wearing away of dopamine producing neurons, which leads to the premature loss of dopamine.

Although surgical treatments fell out of favor after the discovery of Ldopa, they have made a comeback in recent years, thanks in large part to the development of animal models of Parkinson’s. These models, developed with the aid of National Institutes of Health (NIH) funding, have enabled scientists to pinpoint which structures deep within the brain are contributing to symptoms of Parkinson’s—and thus are targets for therapeutic intervention.

In the mid-1990s, researchers reported that deep brain stimulation of the part of the brain called the thalamus suppressed tremors in patients. The technique uses a surgically implanted electrode connected to a pulse generator implanted under the skin that can be adjusted to control the disabling shaking and trembling caused by the disease. And more recently, scientists have identified other targets for stimulation that can alleviate the other symptoms of slowness of movement and stiffness.

New medications and surgical techniques have greatly improved the lives of people with Parkinson’s, but they are not a cure. Backed with NIH grants, researchers are actively searching for treatments that will slow, prevent, or reverse the disease, rather than just lessen its symptoms.

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In some children the problem may resolve on its own, usually within the first few years of life. If it persists then most individuals will require treatment.

Medications to control the heart rate don’t always work, or else the medications cause unwanted side effects. Even when medications are effective it is not desirable for patients to continue such treatment over many years. Removing the extra pathway, via catheterisation, usually cures the disorder. This can be done effectively in most patients after the age of about seven years. In many cases, the extra pathway is easily found, but sometimes it’s difficult to locate. If it cannot be found or eliminated safely then long-term medication may be necessary or surgery might be recommended.

A person with Wolff-Parkinson-White syndrome will need ongoing monitoring, such as regular ECGs, to make sure their heart is functioning normally.

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