Bilingual awake craniotomy with English and Polish language mapping in a 15-year-old patient provides evidence for the role of the left superior temporal gyrus in language switching.

The utility of intraoperative mapping in multilingual patients with brain tumours in speech-eloquent locations is evidenced by reports of heterogeneity of the location and number of language areas. Furthermore, preserving the ability to switch between languages is crucial for multilingual patients' communication and quality of life. We report the first case of intraoperative bilingual and language switching testing in a child undergoing awake craniotomy for a tumour within the left superior temporal gyrus using a novel test paradigm. Stimulation of the posterior superior temporal gyrus resulted in anomia when switching from Polish to English, in the absence of any stimulation effect on switching from English to Polish or object naming in each individual language.