Electrical Stimulation Mapping of Multilingualism

Abstract

Language mapping is commonly practiced in brain tumors and epilepsy surgeries. It is done by direct electrical stimulation of the brain during awake craniotomy or by placing subdural electrodes on the brain's surface, or both. Studies of the language mapping in bi- or multi-lingual patients have concluded that they have both "language-specific areas," in which symptoms are evoked upon stimulation in one specific language and not in the other languages, and "common areas" or "overlapping areas," in which positive findings are evoked in all languages evaluated. The distribution of the pattern of language areas associated with each language, however, varies widely from patient to patient due to multiple factors such as the age of language acquisition, the language proficiency level, the amount of exposure to each language, the location of the lesions, the duration of the diseases, and other factors. Language mapping in bi- or multi-lingual patients should be done by screening all languages the patient speaks.