A novel high-resolution test battery for language mapping in awake craniotomy: preliminary perioperative results in neurooncologic patients

Objective – Recent data underscore the impact of supramarginal resection of gliomas on prolonging survival. The state-of-the-art approach, aimed at preventing permanent postoperative neurological deficits, involves intraoperative functional mapping and monitoring of eloquent regions. Awake surgery has thus become the gold standard method to assess language function. However, at present, no test battery is sensitive enough to reliably detect and map complex language functions intraoperatively–functions that are crucial for patients’ communicative abilities and strongly impact their quality of life. Except for the dated (60 years old) sentence-level Token Test, patients’ language is typically examined at the word level (e.g. picture naming and identification). We have developed and administered six highly sensitive sentence-level tests that reflect a broad range of supra-lexical language functionalities. To assess test sensitivity, we compared the results of our 6 new tests to those of a battery of 11 standard tests. Patients and methods – In this retrospective, monocentric analysis, 48 patients with eloquently located tumors and electively planned awake surgery were analyzed pre- and postoperatively using standard language assessment and our app-based high-resolution test battery. Results – A novel set of supra-lexical simple and complex sentence-level tests is at the heart of this work. Most patients performed equally well on simple sentence-level and standard tests. Performance on linguistically complex sentence-level tests was significantly lower and showed high between-patient variability, as was demonstrated by a variety of statistical analyses. Conclusion – Our results underscore the value of tests that feature complex sentence-level stimuli used in everyday communication. The more complex tests exhibit significantly higher sensitivity compared to standard language assessment. Our results thus demonstrate the utility of such tests in preserving patients’ postoperative quality of life and call for their widespread use in awake surgery.