BRMP-02. Feasibility and evaluation of a novel language paradigm for intraoperative language testing

Abstract

Abstract INTRODUCTION Mapping language during direct cortical stimulation (DCS) in the stetting of awake craniotomy might be challenging without using more than one language paradigm. Applying several language tasks leads to increasing surgery times and to patient’s exhaustion. Additionally, a single language trial must be performed in less than 4 seconds to avoid DCS-induced seizures. Therefore, we aimed to design a single language paradigm which pictures highly relevant language functions and simultaneously restrains the assessment time of single language trials up to 4 seconds. METHOD The intraoperative language task comprised a combination of picture naming and verb generation. During DCS patients should generate correct sentences according to the language stimulus by not exceeding 4 seconds. To assess the intraoperative feasibility of the language task we included 30 healthy subjects in a pilot study to measure subjects’ speed of performing a single language task trial and to evaluate the language paradigm according to its language sensitivity by using the paradigm as a task for functional MRI. Intraoperatively, 21 patients with brain tumors in language associated brain areas were included. Patients received neuropsychological testing before and after surgery. RESULTS The pilot study showed in healthy subjects that by applying the novel paradigm during fMRI there is activation in a left accentuated network of inferior frontal and parietal regions and the superior and middle temporal gyrus (p<.05, FEW). It was feasible to conduct a single language trial of the novel paradigm in a time frame of 4s (performance speed 2.53 s; SD=.32s). Intraoperatively, tumor patients showed DCS-associated language errors while conducting the language task. Postoperatively, mild language but no other neuropsychological deteriorations compared to presurgical assessment were observed (p<.05). CONCLUSION We present a novel language paradigm which safely pictures and monitors highly relevant language functions and consequently can minimize postoperative language deficits.