PITTSBURGH (AP) _ Jerrod Ongley can write and feed himself for the first time at the age of 17, with help from a device meant to help older patients wracked by the tremors of Parkinson's disease.

An electrode that stimulates the brain to block tremors was implanted in Jerrod's head last week at Children's Hospital. He is believed to be the first cerebral palsy patient to receive one.

Surgeons played a videotape Monday showing Jerrod struggling unsuccessfully to keep from spilling water out of a cup placed in his hand. After the implant was activated, the boy was able to grasp the cup and drink.

Jacalyn Ongley said her son had been frustrated all his life by being unable to feed himself.

``He would end up with mashed potatoes in his eyebrows. When you're 17, it's very socially unacceptable,'' she said.

``It's going to change his life. We're excited about what it can do for other kids, too.''

Dr. Leland Albright, chief of pediatric neurosurgery at Children's, said the hospital plans to use the implant to treat up to 10 cerebral palsy patients next year.

Dr. Murray Goldstein, medical director of the United Cerebral Palsy Research and Education Foundation in Washington, said he knows of no other cerebral palsy patients who have been treated with the implant.

``I look forward to hearing more about it,'' Goldstein said. ``It's an approach that certainly demands looking into.''

However, he cautioned that the procedure is so new that the long-term effects are unclear.

``Going into the human brain with electrodes is not in itself an innocuous procedure,'' Goldstein said. ``When you start doing it to children and young adults, it's an effect that is going to last a lifetime.''

The Activa system of Fridley, Minn.-based Medtronic Inc. _ the brand name of the implant _ was approved in August for Parkinson's patients by the Food and Drug Administration. Doctors said that allows them to use the device on patients with similar neurological problems.

Medtronic representatives did not return telephone messages seeking information on how many Parkinson's patients have received Activa implants.

Parkinson's, a degenerative disease that generally affects older adults, is caused by irregularities in chemicals, especially dopamine, that regulate the thalamus, a walnut-size region in the center of the brain. Researchers do not know why some people contract the disease.

Cerebral palsy is the term for a variety of brain damage caused before or at birth by an insufficient supply of blood and oxygen to the brain.

Only about 15 percent of the 500,000 Americans with cerebral palsy suffer from tremors caused by damage to the thalamus, doctors said.

In the procedure, which costs about $25,000, doctors implant an electrode into the thalamus. A wire runs under the scalp from the top of the head to the collarbone, where a battery-powered ``pulse generator'' the size of a cigarette lighter is implanted. The generator sends 180 electrical shocks to the thalamus each second.

A patient can turn the device off at night to conserve the battery, which must be surgically replaced every three to five years.