Imagine going in for dental surgery with an Oregon accent, and coming out with a mixture of Northern British, Scottish, Irish and a hint of Eastern European. This is what happened to Karen Butler, 56. She woke up from anesthesia sounding like somebody from the British Isles.

After undergoing several tests, experts say she has “foreign accent syndrome“, an extremely uncommon neurological disorder – only 60 cases have been identified since 1941.

Butler, of Toledo, Oregon, underwent the dental procedure 18 months ago. When she started speaking after the procedure she said “I sounded more like I was from Transylvania.”

As foreign accent syndrome is only present when the patient has suffered a stroke or some kind of brain damage, doctors are bewildered.

When interviewed in Meredith Viera’s TV “Today” show, Butler explained that doctors had told her she is physically fine. She has no vision problems, her motor skills are functioning properly, and she has no signs and symptoms of brain damage or stroke.

Experts believe Butler’s condition will gradually fade, and her original accent will come back.

According to Butler, her new condition is a source of fun and enjoyment for her and her husband, and feels like a new toy.

Butler said:

“You talk to young girls they think it’s a very, very pretty sound. And they say, ‘I want an accent like that.’ Oh, well just go see my dentist. He only charges $7,000.”

Apparently, when Butler talks she is not aware of her new accent. She only notices when listening to a recording of her voice.

Foreign accent syndrome is an extremely rare medical condition in which the patient speaks with an accent which is not related to their environment or upbringing. It usually occurs after a sever brain injury, such as a head trauma or stroke. In one case, a patient developed the syndrome after a severe bout of migraine.

Only sixty cases have been recorded between 1941 and 2009.

Experts say Foreign Accent Syndrome occurs when the person’s coordination processes and articulatory planning become distorted. The patient does not acquire a new language – their vocabulary and grammar remain the same. They simply pronounce their native language differently.

In the majority of cases, the patient acquires an accent from an area or country which also speaks their language. For example, a Londoner might start talking like a New Yorker.