Dr. Friedemann Müller, the chief physician at the Schön Clinic, a private hospital with campuses around Germany, said that Ms. Abdulla had been in a state of minimal consciousness. He said only a handful of cases like hers, in which a patient recovered after such a long period, had been recorded.

Patients in a state of reduced consciousness are usually classified into three categories. In a full coma, the patient shows no signs of being awake, with eyes closed and unresponsive to the environment. A persistent vegetative state includes those who seem awake but show no signs of awareness, while a minimally conscious state can include periods in which some response — such as moving a finger when asked — can be noted. Colloquially, all three categories are often described as comas.

Signs that Ms. Abdulla was recovering started to emerge last year when she began saying her son’s name. A couple of weeks later, she started repeating verses from the Quran that she had learned decades ago.

“We didn’t believe it at first,” Dr. Müller said. “But eventually it became very clear that she was saying her son’s name.”

Dr. Müller said he had not expected such a recovery from Ms. Abdulla.

She had been at the German clinic for treatment for seizures and contorted muscles that made her body hard to handle and that kept her from being able to sit in a wheelchair safely. Part of the treatment was to install a device that delivered medication directly into her spine, a factor that Dr. Müller said could have brought on her recovery.