MEDICAL SURFARI: PARKINSON'S DISEASE HAS LONG HISTORY

In 1817 a London physician named James Parkinson published "An Essay On The Shaking Palsy," and this has since become well known by almost everyone as Parkinson's disease. Although Parkinson's disease is a common progressive neurological disorder resulting from degeneration of specific nerve cells in a region of the brain controlling movement, this condition and its therapies were described in the Ayurveda, the system of medicine practiced in India as early as 5000 B.C., and in the first Chinese medical text, Nei Jing, which appeared about 2,500 years ago. It wasn't until the early 1960s that researchers identified a fundamental shortage of a signaling chemical (neurotransmitter), dopamine, resulting in impaired movement.

Parkinson's disease belongs to a group of nervous system conditions called motor system disorders. Often the first symptom of Parkinson's disease is tremor (trembling or shaking) of the limbs, especially when at rest. Other symptoms of Parkinson's disease include facial tremor, rigidity or stiffness of the limbs and trunk, slowness of movement and impaired balance or coordination. Some patients develop a stooped posture and shuffling gait while others become so stiff and rigid they are unable to move. This disorder may progress to the point of difficulty walking, talking or completing other simple tasks. People with Parkinson's disease often reveal less facial expression and they may speak in a very soft, trembling voice. This disease may cause depression, personality changes, impaired intellectual function, sleep disturbances and sexual difficulties.

In the United States alone, about 50,000 new cases are reported every year. The first symptoms appear, on average, at about age 60; although, it is most frequent among people in their 70s and 80s and slightly more common in men. There may be nearly a million people affected in the United States alone.

There are many theories about the cause of the disease, but so far no research has provided conclusive proof that a single mechanism is responsible for the disease. Many researchers believe that a combination of oxidative damage, environmental toxins, genetic predisposition and accelerated aging may cause the disease.

There are many stages of Parkinson's disease and even for an experienced neurologist, making an accurate diagnosis in the early stages of Parkinson's disease can be challenging. As of yet, there are no blood or laboratory tests available to diagnose the disease. Parkinsonian symptoms may also appear in patients with other clearly distinct neurological disorders. Consequently a physician may need to observe the patient for some time to correctly diagnose Parkinson's disease. Since other neurological diseases may have similar features (Parkinsonism) but require different treatments, making a precise diagnosis early is essential for starting a patient on proper medication.

There are no cures for Parkinson's disease although a simple chemical found naturally in plants and animals, Levadopa, may be converted by the body to dopamine, which in turn replenishes the brain's dwindling supply. This medication helps about 75 percent of patients with Parkinsonian symptoms. Not all of their symptoms, however, respond equally well to the medication. It seems that slow movement and rigidity respond best. Although Levadopa may diminish symptoms, it is not a cure as it does not replace lost nerve cells or stop the progression of the disease.

Many have wondered whether improved diet or exercise may arrest or reverse this degenerative disease. Although eating a well-balanced, nutritious diet and exercising for improved mobility can be beneficial for anyone, there does not seem to be any specific diet or exercise treatment that alters the course of the disease.

For patients that are severely affected, especially by tremor in their dominant hand, there are various kinds of minimally invasive brain surgeries that have been effective in reducing symptoms. These surgical treatments include creating a small interruption of the neural circuits within the thalamus (a "relay station" near the center of the brain) to obliterate the area producing the tremors. More recently, an electrical stimulator has been developed that may be implanted in the thalamus to counteract the loss of the Dopamine nerve cells, which in turn stops or greatly reduces the tremor.

Clearly, medical research has laid the foundation for scientists to develop new medications and treatments that may help physicians to delay, prevent or even reverse this disease.

World Wide Web Resources

Parkinson's Disease: Hope Through Research

www.ninds.nih.gov/healinfo/disorder/parkinso/pdhtr.htm

This Web site is provided by the National Institute of Neurological Disorders and Stroke (NINDS), the leading supporter of research on disorders of the brain and nervous system, including Parkinson's disease.

Facts About Parkinson's Disease

www.nhgri.nih.gov/DIR/LGDR/PARK/about_parks.html

This Web site provides background information on Parkinson's disease as well as links to other sites that provide additional sources for those interested in the disease.

Dr. Scott Gibbs is a Cape Girardeau neurosurgeon and editor-in-chief of Mosby's Medical Surfari. You may e-mail questions to him at drgibbs@semissourian.com or write in care of the Southeast Missourian, P.O. Box 699, Cape Girardeau, Mo., 63701.