Location of language in the cortex: a comparison between functional MR imaging and electrocortical stimulation.

TLDR

The study aimed to assess how accurately fMRI can locate language cortex for surgical planning. The authors compared fMRI language maps with electrocortical stimulation by overlaying digitized intraoperative photographs, evaluating sensitivity and specificity across five language tasks and varying activation borders. fMRI achieved 81–92% sensitivity but only 0–53% specificity, with combined tasks outperforming single tasks, and its accuracy varied across subjects and tasks, supporting its use as a noninvasive presurgical language mapping tool.

Abstract

PURPOSE To determine the accuracy of functional MR imaging in locating language areas for planning surgical resection. METHODS Intraoperative photographs were digitized and overlaid on functional MR language maps. The sensitivity and specificity of functional MR imaging for identifying language areas were determined for five different language tasks by comparing functional MR areas of language activation with results of electrocortical stimulation. A match was considered to occur if an activated area contacted overlapped, or surrounded a language tag. The borders of the activation areas were extended by 1 and 2 cm to determine whether the number of matches changed. Language and nonlanguage tag matches were tabulated separately. RESULTS Sensitivity/specificity for all patients and all language tasks ranged from 81%/53% for areas that touched to 92%/0% for areas separated by 2 cm. Individual language tasks were not as sensitive as a battery of language tasks combined. Location of language areas varied among subjects for a given task and among tasks for a given subject. CONCLUSION Functional MR imaging should be considered a useful presurgical planning tool for mapping cortical language areas, because it is sensitive, it provides increased time for planning before surgery, and it is noninvasive.