At the end of December, Dr. Michael-Gerard Moncman, medical staff president for the Altoona Regional Health System, reluctantly closed his neurosurgical practice and prepared to relocate to Dayton, Ohio.

"It's a move predicated on the economics of the situation," he said, surrounded by moving boxes at his Hollidaysburg home. "Over the last three years, I saw medical malpractice premiums taking a bigger and bigger chunk out of my earnings."

Neurosurgeons cite high malpractice insurance costs as one reason why some decide to leave Pennsylvania, contributing to a shortage identified in surveys of the region's hospitals.

About one-third of hospital campuses surveyed by the Pittsburgh Post-Gazette and the Hospital Council of Western Pennsylvania reported having a neurosurgeon available to treat stroke patients within two hours. Nearly all the others said they had arrangements in place to quickly transfer patients to other hospitals.

While many stroke patients do not need neurosurgical care, treatment is critical in a small number of cases, said Dr. Lawrence Wechsler, director of the Stroke Institute at the University of Pittsburgh Medical Center.

Patients with bleeding from a hemorrhagic stroke, or as a complication of receiving the clot-busting drug tPA, may need surgery to accommodate swelling and reduce damage to other areas of the brain, Dr. Wechsler said.

Dr. Jack Wilberger, chairman of neurosurgery at Allegheny General Hospital, recalled several local neurosurgeons who have left in recent years, including two who moved to Ohio "because they could get paid twice as much."

The shortage is particularly acute in communities north and east of Allegheny County, he said.

The number of neurosurgeons practicing in the state has dropped by about 25 percent since the late 1990s, when there were more than 200, said Dr. Daniel Bursick, past president of the Pennsylvania Neurosurgical Society. He took over as president when his predecessor moved to Maryland two years ago.

An even smaller number of those who are left are willing to provide after-hours coverage in emergency rooms, said Dr. Bursick, chief of neurosurgery at Mercy Hospital.

Compensation is one factor prompting neurosurgeons to work elsewhere, he said, adding, "We're getting outbid across the country."

According to survey results published last fall by Sullivan, Cotter and Associates, neurosurgeons in the Northeast earned less than those in other parts of the nation.

Regulatory requirements are another concern among neurosurgeons, Dr. Bursick said, noting, for example, that the state places limits on providing certain diagnostic services in doctors' offices that do not exist elsewhere.

"But what really drives people over the edge is malpractice," he said.

In its October newsletter, Chicago-based Medical Liability Monitor noted that Pennsylvania doctors pay among the highest malpractice insurance premiums in the country. Neurosurgeons and other high-risk specialists tend to pay especially high premiums.

Doctors in Pennsylvania must purchase coverage for $1 million per claim and $3 million for all claims in a single year, said Anna Lavertue, spokeswoman for PMSLIC, the largest carrier of medical malpractice insurance in the state.

Half of the coverage is provided by a primary insurance carrier, she said, and the rest by the MCARE fund, a state insurance program.

In 2003, state lawmakers approved a proposal by Gov. Ed Rendell to help doctors pay for their coverage through MCARE. While many doctors pay reduced MCARE assessments, neurosurgeons and doctors in a few other specialties may avoid paying the assessments entirely.

That means neurosurgeons in Pittsburgh may not have to pay about $33,000 to MCARE on top of the average annual premium of about $67,000, said Amy Kelchner, spokeswoman for the Governor's Office of Health Care Reform.

The rates in Pittsburgh are lower than in some other Pennsylvania cities, she said.

Neurosurgeons point out that while the MCARE abatement helps, it may not continue, noting that it was extended last fall for only a year.

Ms. Kelchner said the state never intended to pay the subsidies indefinitely.

"The idea was, we would do it for a few years until we saw some positive changes in the medical malpractice environment. We hope that's happening."

Ms. Lavertue noted that premium increases by her company have moderated, from 40 percent and 54 percent, respectively, in 2002 and 2003 to 15.1 percent in 2004 and 10.8 percent in 2005. No increase is planned this year, she said.

Without the MCARE abatement, the state would have an even more difficult time retaining neurosurgeons, Dr. Moncman said.

An Allentown native who practiced in Altoona for 17 years, Dr. Moncman, 53, said that deciding to leave Pennsylvania was difficult.

"I hate to go. I really do," he said, noting that his mother lives in Allentown and his daughter, a University of Pittsburgh graduate, is in law school at Widener University in Harrisburg. Because of the move, his wife, Patricia, also gave up her nursing director's job at the hospital.

But he said he lacked the energy to continuing dealing with spiraling malpractice insurance costs in his home state. "I decided it was time to go."