Thomas Wayne Wright, the New Carrollton youth charged in the murder of 8-year-old Brian Zippert, suffered from a neurological disorder that required surgery to relieve pressure on the brain, his lawyer said yesterday.

Despite the implantation of a tube to drain fluid from his brain, which seemed to relieve any symptoms of distress, Wright, 17, experienced headaches over the last three weeks, according to his attorney, Jeffrey T. Wennar of the public defender's office.

As Wennar obtained court approval yesterday for a medical examination of his client, a picture emerged of Wright as a youth with special medical problems that may have affected his behavior.

Persons familiar with the family said Wright was also deeply affected by the death of his father of a heart attack at the age of 36 a year or two ago.

Brian Zippert was reported missing last Wednesday night. He was found strangled the next morning in a wooded area near the Carrollan Gardens apartment complex close to the junction of Rte. 450 and the Beltway, where he and Wright both lived. Wright was arrested Saturday night after police said they found inconsistencies in his statements. He is charged as an adult and has not yet entered a plea.

Wright, according to friends and police sources, had helped organize the search for the missing boy and said he hoped the culprit would be caught.

A slight youth who received special education and was a year behind his age group at Greenbelt's Eleanor Roosevelt High School, Wright was known as a loner who preferred the company of younger children.

Eric McGraw, 20, also a resident of Carrollan Gardens, said Wright would accompany younger children "if they went up to the store . . . make sure nobody bothered them and walk them home."

The operation on Wright last July apparently followed a football accident, his friends said. Doctors discovered several growths in the youth's brain, Wennar said. Friends said the youth spent three months in the hospital and was limited afterward in his physical activities. Wright had experienced school problems before the operation that seemed to lessen after the surgery, until recently, Wennar said.

"We are looking at some very serious neurological problems," James E. Kenkel, the county's chief public defender, said.

Ray Ogden, the Roosevelt High School principal, said Wright "received special education services" in reading, social studies, mathematics and science but otherwise participated in the regular 10th-grade curriculum.

Ogden described Wright as a quiet youth who worked as an office aide last year. "He would do what you asked him to do," he said.

In class, Wright seemed withdrawn and sometimes stared blankly, some of his classmates said. "He had a short temper" in elementary and junior high school, said Hoby White, an 11th grader who had attended school with him over the years.

Jimmy Reid, 16, a neighbor of Wright's, said the two of them had occasionally cut class together. "We'd go in the library, sit and talk or get books to make it look like we were working," he said.

Reid and McGraw both said, however, that Wright usually did his homework assignments. McGraw said he helped Wright's mother load their belongings into a van Monday night, as the family temporarily moved to an undisclosed location.

Wright is one of five children, ranging in age from 7 to 21. He and two of his siblings regularly attended church, neighbors said. Mary Wright, his mother, is a nurse at a Washington hospital, who has often worked six days a week, several sources said. She and her husband, who neighbors said was an auto mechanic, were separated, but he continued to visit his children before his death.

Thomas Wright and his oldest brother, David, were deeply affected by their father's death, Reid and McGraw said. "Everytime somebody brought up their father, they'd start crying," Reid said. Wennar, Wright's lawyer, spoke to the youth yesterday in the county detention center where he is being held without bond. "Here's a kid who is really young and very scared," he said. "He knows what's going on, but he is very frightened."