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Parkinson's patients who underwent implantation of embryonic cells had better motor performance following the surgery than patients who didn't receive the cells, according to a paper published in the June issue of The Archives of Neurology by researchers at NewYork-Presbyterian Hospital/Columbia University Medical Center.

The researchers report on data collected from the first double-blind, placebo-controlled trial of embryonic cell implants (NOT embryonic stem cells) for Parkinson's disease. The main results of that study, published in the New England Journal of Medicine in 2001 (NEJM 344: 710-719), showed a slight improvement in Parkinson's symptoms among younger patients who got the implants, but also found that many developed additional movement problems a year after the surgery.

Using an objective and sensitive measure, the new paper finds that the implants even improved motor performance in the older patients, although these improvements were subtle and don't affect the day-to-day functioning of the patients.

What the results show is that embryonic cell transplantation affects motor coordination in Parkinson's patients, but specific treatment recommendations were not the main intent of this physiological branch to the study, says senior author Dr. Seth Pullman, associate professor of clinical neurology at Columbia University College of Physicians Surgeons and director of the Clinical Motor Physiology Laboratory at NewYork-Presbyterian Hospital/Columbia University Medical Center.

Parkinson's disease is a neurodegenerative disorder in which dopamine-producing neurons in one region of the brain die. The loss of the cells, and the dopamine they produce, causes tremors, rigidity, and slowness of voluntary movement.

Drugs can treat the symptoms to some extent, but there is no way to slow or reverse the death of the cells. Embryonic cell implants, were tested to see if embryonic dopamine-producing cells could replace neurons lost in the disease and improve symptoms.

In the current study, Dr. Pullman and colleagues measured the patient's reaction and motor times before the surgery and 4- and 12-months after surgery. Reaction time measures the time it takes a patient to process a command, for example, the time it takes a patient to begin moving a hand after being directed to touch a computer screen. Motor time measures the time it takes a patient to accomplish the command once the hand begins moving. When combined together, the time provides an overall measure of motor performance. Twenty patients had received tissue implants and 19 control patients underwent the same surgery but did not receive any tissue.

The results showed that the implants stopped deterioration of motor performance seen in older (> 60 years) control patients who did not receive the implant. After one year, older patients who received implants maintained the level of motor skills they had prior to surgery, while the motor skills of older control patients deteriorated.

The difference may reflect ongoing neurodegeneration in the control group,or stabilization of neurodegeneration in the group that received implants, says first author Dr. Paul Gordon, assistant professor of neurology at Columbia University College of Physicians and Surgeons and assistant attending neurologist at NewYork-Presbyterian Hospital/Columbia University Medical Center.

This study was supported by a grant from the National Institute of Neurological Disorders and Stroke and the Parkinson Disease Foundation.