Parkinson's Disease

POSTED: 10:57 am EDT July 27, 2007, Charlotte, N.C.
http://www.wsoctv.com/health/1376795...alth?fromrss=1

Parkinson's disease is a neurological condition that affects movement. It occurs when a substantial number of nerve cells in an area of the brain called the substantia nigra, malfunction and die off. These cells are responsible for production of dopamine, a chemical that sends information to the parts of the brain that control initiation and continuation of smooth, purposeful movement.

There are four characteristic signs of Parkinson's disease. Tremor is an uncontrolled shaking, often in a hand or foot on one side of the body. The shaking most commonly occurs when the limb is not moving (hence, it is sometimes referred to as a "resting" tremor). Sometimes the tremor occurs in the jaw or face. About 70 percent of patients with Parkinson's experience tremor in the early stages of the disease.

Slowness of movement (bradykinesia) may cause slow, shuffling steps or problems initiating movement (including sudden stopping). This symptom may affect the ability to walk or perform simple chores, like buttoning a shirt.

Rigidity is increased muscle tone, or stiffness. Normally, the muscles stretch during movement and relax when the movement is stopped. In people with Parkinson's, the muscle of an affected limb is stiff and unable to move naturally, leading to a decreased range of motion.

Postural instability is impaired balance and coordination. The condition may cause a patient to fall while standing, walking, making a sudden turn or when getting up out of a chair.

According to the National Parkinson Foundation, 1.5 million Americans have Parkinson's disease. About 60,000 are diagnosed with the condition each year. Parkinson's is most common in older people. But about 15 percent of patients are diagnosed before 50.

Treating Parkinson's Disease

There is no cure for Parkinson's disease. Patients are often given levodopa, a medication used by the brain to make dopamine. Levodopa is typically combined with another drug, called carbidopa, which delays conversion into dopamine until the levodopa reaches the brain. Levodopa is best for reducing slowed movement and rigidity.

Other medications may be used alone or in combination with levodopa. An antiviral drug, amantadine, helps reduce fatigue, tremor and slowed movement in some patients with early Parkinson's. Anticholinergic medications may be used to reduce tremor or rigidity. Selegiline may be prescribed for tremors, stiffness, spasms and loss of muscle control. It may also help reduce depression in Parkinson's patients. Last year, the FDA approved another drug, rasagiline, for control of symptoms in patients with advanced Parkinson's disease.

When medications fail to work, patients may be eligible for a surgical procedure called deep brain stimulation. Electrodes are implanted into target areas of the brain. A programmable pulse generator sends an electrical signal that stimulates the cells in the target area that control movement. The treatment blocks the actions of abnormal nerve signals that cause some of the symptoms associated with Parkinson's disease.

"Eyeing" Up a Treatment

Most patients eventually stop responding to levodopa. So researchers have been looking for better ways to increase the supply of dopamine in the brain. One potential treatment comes from an unexpected source - the eye. Within the inner layer of the retina, or light-sensitive membrane at the back of the eye, there are a group of cells, called retinal pigment epithelial (RPE) cells. These cells produce pigment. But more importantly, they produce dopamine.

In some preliminary studies, researchers have been able to retrieve some of the RPE cells from deceased donors and then transplant those cells into the brains of Parkinson's patients. While the trials are very small, they hold promise. One study found six patients with advanced Parkinson's had a 48 percent improvement in their symptoms 12 months after the treatment. The improvement was sustained for another year (24 months after the initial treatment).

Researchers at the University of Arizona hope to one day be able to retrieve RPE cells from Parkinson's patients and implant them back into their own brains. Ideally, the treatment would enable the patient's body to make its own dopamine without risk of rejection or disease transmission. Neurologist, Scott Sherman, M.D., Ph.D., says RPE transplantation would still not be a cure for Parkinson's disease. But it may be able to allow patients to keep their symptoms under control and/or slow progression of the disease.

# For information on Parkinson's Disease: The Michael J. Fox Foundation for Parkinson's Research
# National Institute of Neurological Disorders and Stroke

It seems like everybody is getting in on the "eye" treatment. Seven years ago when I had experimental surgery using retinal cells, it was unheard of.

There is the STEPS trials (Spheramine), where cells are taken from a donor eye. because of the method in which they are dellivered (micro-carrier beads), no immunosuppressants are needed.(That's a big word meaning you don't have to take anything to keep your body from rejecting these cells).
See www.titanpharm.com and look under Clinical Experiences.

There is also a stem cell retinal cell surgery done in China.
See www.stemcellschina.com and look under Patient Experiences.

And now, of course, this one in Arizona that uses autologous retinal cells (from the patient - not a donor). All are based on dopamine replacement. It's good to hear of so many people interested in treating PD.

Peggy

the following article was printed in the China Medical Journal.

http://www.cmj.org/Periodical/PDF/20073559382420.pdf

frank