A 17-year-old in the Netherlands came out of anesthesia after knee surgery speaking only English, a language he had used only in school. He could not speak or understand Dutch, his native language, did not recognize his parents, and insisted he was in Utah, a place he had never been.
The episode lasted about a day. His doctors at Maastricht University Medical Center+ described it as foreign language syndrome in the Journal of Medical Case Reports, a condition in which a person switches from their native language to a second one for a period of time. The report was published in January 2022 and drew a fresh wave of international attention in 2025. Every earlier case the team could find involved an adult.
Their most intriguing argument is about what the syndrome actually is. The authors suggest it may not be a separate disorder at all, but an unusual form of emergence delirium, the confusion some patients experience as anesthesia wears off.
Hours Without a Single Dutch Word
The teen was having surgery for cartilage damage in his knee after a football injury. It was his first operation and his first time under anesthesia. He had no psychiatric history, and his inherited clotting disorder, factor V Leiden, was under control, according to the report.
He had spoken only Dutch all his life, including a southern dialect called Limburgish, and had spoken it that morning. He learned English in school classes, never spoke it outside them, had no relatives in English-speaking countries and had not recently visited one.
In the recovery room, a nurse noticed he was speaking English. She assumed it was emergence delirium and was not initially worried. As the hours passed and staff still could not get Dutch from him, a psychiatric consultation was requested.
His English itself became a point of disagreement. The physicians found it adequate but not fluent, while the nurses and his mother thought he spoke it fluently.
About 24 hours after surgery, when friends came to visit, he suddenly understood and spoke Dutch normally again. He later remembered speaking English, not recognizing his parents and believing he was in the United States.
No Sign of Brain Injury
A neurologist found nothing abnormal on a complete neurological exam and saw no reason for further tests, so no EEG or brain imaging was done, and the teen went home a day later. Three weeks after discharge, he reported no trouble with Dutch and no changes in mood, anxiety or sleep, though he described reduced concentration and fatigue after the operation.
A later neuropsychological evaluation found no sign of cognitive impairment.
That separates the case from foreign accent syndrome, a different condition in which people keep speaking their native language but with pronunciation that sounds foreign. A review in Neurology International notes that foreign language syndrome is distinct from it, often arises after anesthesia, brain injury or psychological stress, and typically shows no structural damage on brain scans.
A Pattern Seen After Anesthesia
The Maastricht team found only eight earlier published cases of foreign language syndrome. All involved adults, six of the eight were older than 50, and almost all were men. Fentanyl, midazolam, and propofol were the most commonly reported anesthetics.
The authors pointed to close similarities between the syndrome and emergence delirium. Both begin after surgery, possibly in connection with anesthesia; both involve confusion, and both usually resolve within hours. Emergence delirium itself typically begins and ends within minutes to hours after general anesthesia is stopped, according to a review of delirium after surgery.
The open question, as the authors framed it, is "whether it is a syndrome of its own or a phenotype of emergence delirium." A phenotype, in this sense, is a particular form in which a condition shows up.
Language and Confusion After Surgery
Foreign language syndrome is exceedingly rare, but postoperative delirium is not, and language may matter for that more common problem, too. In research presented at the ANESTHESIOLOGY 2025 annual meeting, a Beth Israel Deaconess Medical Center team analyzed 49,588 surgical patients and found that those whose primary language was not English were 23% more likely to develop delirium after surgery, according to the American Society of Anesthesiologists. About 8.7% of those patients named a primary language other than English, most often Spanish or Cantonese, and the added risk was higher among those with lower estimated household incomes. Interpreter support did not appear to lower the risk, and delirium in these patients was tied to longer hospital stays.
The analysis, since published as a retrospective cohort study, shows an association, not cause. The researchers noted that interpreter services are not always readily available on hospital wards and in intensive care units in the first days after surgery, when most delirium occurs.
For families, the Dutch case is ultimately reassuring, because the teen recovered without signs of lasting cognitive problems. Still, it is one patient, and the cause remains unknown. Anyone who notices sudden confusion, disorientation, or language changes in a loved one after surgery should alert the care team right away.
Key Questions Answered
What happened to the Dutch teen?
After knee surgery under general anesthesia, he spoke only English, could not speak or understand Dutch, did not recognize his parents, and believed he was in Utah. He recovered within about 24 hours.
What is foreign language syndrome?
It is a rare condition in which a person temporarily switches from their native language to a second language, most often reported after surgery and anesthesia.
Is it the same as foreign accent syndrome?
No. In foreign accent syndrome, people keep their native language but sound as if they have a foreign accent, often after brain injury.
What caused it?
No one knows. His doctors suspect it may be an unusual form of emergence delirium, the confusion that can follow anesthesia.
Did he have lasting effects?
He reported reduced concentration and fatigue after the operation, but a later neuropsychological evaluation found no cognitive impairment.
What should families watch for after surgery?
Sudden confusion, disorientation, or changes in speech or language should be reported to the care team promptly.
