CONCORD, N.H. — New Hampshire public health officials say an autopsy has confirmed that a patient who may have exposed others to a rare brain disease died of Creutzfeldt-Jakob disease.

After the patient died in August, officials suspected Creutzfeldt-Jakob, an always-fatal disease characterized by rapidly progressive dementia. But the only way to confirm it is through a brain biopsy or autopsy.

Because the patient had brain surgery at Catholic Medical Center in May, officials warned eight other patients that they may have been exposed because the proteins that cause the disease survive standard techniques used to sterilize surgical equipment.

Five others in Massachusetts and Connecticut also were notified because the equipment was rented and used elsewhere. But officials said such transmission is extremely rare.