Donlin M. Long, founding chair of the Johns Hopkins University School of Medicine’s Department of Neurosurgery and a pioneer in the treatment of chronic pain, died Sept. 19. He was 89.

Highly regarded for his neurosurgical skills, extensive impact on pain reduction research and neurological studies and mentorship of medical students, residents and fellows, Long is credited with establishing the Department of Neurosurgery at Johns Hopkins in 1973, which until then had been a division of the Department of Surgery.

“Don Long was a true renaissance man and an innovative, master neurosurgeon who nurtured generations of neurosurgical leaders who have transformed our field,” said Henry Brem, M.D., the Harvey Cushing Professor of Neurosurgery and Director of the Department of Neurosurgery at the Johns Hopkins University School of Medicine. “Dr. Long was compassionate and a great role model.”

When Long joined Johns Hopkins, he organized, what were called at the time, “centers of expertise,” providing patients with one-stop access to specialists in neurology, neurosurgery, orthopaedics and other specialties.

Long also popularized the concept of competency-based training for neurosurgeons. By the time he stepped down as department director in August of 2000, the full-time neurosurgical faculty had more than doubled, the surgical caseload had increased substantially, rising to some 3,500 annually at The Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center, seven centers of expertise had been created, bringing together experts on everything from chronic pain and vascular diseases to skull base surgery and spinal diseases, and research funding had grown exponentially to $5.5 million a year.

Descended from New England Quakers, Long was born on April 14, 1934, in Rolla, Missouri. His father was a chemist for the state health department and his mother was a schoolteacher. The family soon moved to Jefferson City. He obtained his undergraduate degree in 1955 and his medical degree in 1959 from the University of Missouri.

As an intern at the University of Minnesota, Long originally planned to become a cardiac surgeon, but changed to neurosurgery after watching pioneer neurosurgeon Lyle French operate.

As a resident at Minnesota, Long and fellow resident Joseph Galicich did the research that led to the now-universal use of steroids to reduce postoperative brain swelling. While earning his 1964 doctorate in neuroanatomy, he also did landmark research on the biological structure of the blood vessels in the brain.

Using a then-new device, the electron microscope, he was able to make the first photographs of the cells that form the inner lining of the brain’s blood vessels, providing images that revealed why brain swelling led to a breakdown of what is known as the blood/brain barrier. This is a special system of cells that form the lining of the brain’s tiniest blood vessels and separate the brain from the central nervous system, protecting it from harmful substances in the bloodstream.

Once he came to Johns Hopkins, Long continued his groundbreaking research into chronic pain, where he designed the first external transcutaneous electrical nerve stimulator — now universally known simply as TENS — for stimulating peripheral nerves to ease pain.

In 1981, he and Johns Hopkins colleagues announced the invention of the first battery-powered, rechargeable, implantable electronic stimulator. It became a standard tool in pain management around the world.

In addition, Long collaborated with colleagues at the Johns Hopkins Applied Physics Laboratory to invent an implantable medication pump, now a standard device used for the administration of insulin in the treatment of patients with diabetes.

Long is survived by his wife of 64 years, Harriett Page Long; three children, Dr. Kimberley Page Riley and her spouse Dr. Lee Hunter Riley, III, Elisabeth Merchant Long, and David Bradford Long and his spouse Dr. Elizabeth Selvin; and four grandchildren, Lauren Palmer Riley, Thomas Hunter Riley, Benjamin Logan Selvin Long and Eli Duncan Selvin Long.