Electrical Stimulation Mapping of Language in Multilingualism

• Published in: Higher Brain Function Research Vol. 42; no. 3; pp. 282 - 286
• Main Authors: Fujii, Masazumi, Maesawa, Satoshi, Futamura, Miyako, Kobayashi, Shunsuke, Hiruta, Ryo
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Society for Higher Brain Dysfunction 30.09.2022
• Subjects: awake surgery; common and specific areas; language mapping; language switching; multilingual
• ISSN: 1348-4818; 1880-6554
• DOI: 10.2496/hbfr.42.282

Electrical stimulation mapping (ESM) is a method to evaluate the brainʼs functional organization in brain tumors and epilepsy patients by directly stimulating it and observing the responses. Many publications have described the cortical organization of language in multilingual subjects : however, the localization patterns among the first, second, and even later languages seem to be diverse and complex. One of the reasons for this complexity is that language organization in multilingualism can be influenced by many factors, such as the age of languages acquisition, languages proficiency level, degree of exposure to each language, degree of language hemispheric lateralization, and localization and duration of the pathology. According to a recent systematic review, it is necessary to evaluate each language separately when performing resection of brain lesions since languages can demonstrate distinctive organization patterns depending on the factors mentioned above. Here, we present two multilingual patients who had awake surgery in which EMS has demonstrated common and specific areas for their languages. Also, some areas elicited language switching after stimulation. Interestingly, in one patient, a significant change in cortical language organization was observed at the time of reoperation, reflecting the process of brain plasticity in slowly growing glial tumor.