Foreign Language Syndrome Strikes Teen, Man
Two case reports describe people who suddenly spoke only English after surgery or medication, with the loss of their native language temporary.
Updated on Nov. 5, 2026 in Language Learning
Psychiatrists in the Netherlands reported a 17-year-old who spoke only English after knee surgery, and psychiatrists in Belgrade, Serbia reported a 34-year-old man who switched to English during a reaction to an antipsychotic drug. In both cases, the native language returned in the following hours, days, or weeks.
Why it matters
The reports describe foreign language syndrome, a rare condition in which a person loses access to a native language, and they suggest the disruption may be a form of delirium. For people who learn or use multiple languages, the cases show how brain disruption can affect language in unexpected ways.
The Dutch teen had cartilage repair after a football injury and received propofol, sufentanil, and morphine, and the Serbian man received an injection of chlorpromazine and was diagnosed with neuroleptic malignant syndrome. The source does not specify how the teams determined the cause of either episode.
The players
Maastricht University Medical Center
A Dutch academic hospital whose psychiatrists reported the case of the 17-year-old teen who spoke only English after knee surgery.
Institute of Mental Health in Belgrade
A psychiatric hospital in Serbia's capital that admitted the 34-year-old man whose English episode was reported by the Belgrade team.
The details
After surgery, the Dutch teen could neither speak nor understand Dutch, and about 18 hours later he could understand Dutch but not speak it, and his speech returned around 24 hours after surgery when friends visited. The Serbian man, who had schizoaffective disorder, did not remember speaking English during his exam, and his case was published in Annals of General Psychiatry in January 2025.
Timeline
July 2024: Serbian man admitted to the Institute of Mental Health in Belgrade for a depressive episode.
January 2025: Serbian case published in Annals of General Psychiatry.
About 18 hours after surgery: Dutch teen could understand Dutch but not speak it.
Around 24 hours after surgery: Dutch teen's Dutch returned when friends visited.
Nearly a year after surgery: Testing showed no cognitive impairment in the Dutch teen.
Language Landscape
The two new reports add to the eight earlier cases the Maastricht team reviewed, and they extend a small body of literature that the source describes as having been built from rare individual reports. The Belgrade team's count of nine documented cases, all in men, further shows how thin the published record remains.
The cases do not describe changes to everyday routines or purchasing decisions. For people who speak more than one language, the reports show that a sudden change in brain function can alter which language a person uses, but the source does not suggest any practical steps for readers.
The takeaway
Language is closely tied to brain function, so a sudden switch to another tongue can signal a medical problem that deserves attention. Anyone who notices a sudden change in speech or comprehension after surgery or medication should seek medical care promptly.
Further reading
Explore more about how the brain handles multiple tongues in our Language Learning section.
Source note: This article includes information reported by Medical Daily.
