To minimize permanent postoperative deficits, functional mapping with direct electrical stimulation (DES) is becoming a gold standard when a brain tumor resection must be performed near or within eloquent areas. Due to the devastating impact of communication disabilities, language is one of the most commonly mapped functions. However, standardized linguistic protocols for intraoperative use are still scarce. Here we present the first Russian standardized naming test for mapping noun and verb production during awake neurosurgeries. Its development has been informed by modern (psycho)linguistic knowledge and DES requirements. The test was clinically piloted in a sample of 23 patients who underwent awake craniotomy, with results showing high relevance of the test in combination with DES for mapping language-relevant cortical and subcortical sites. The use of the test intraoperatively enabled extensive resection of tumor tissue while preserving language function in most of the tested patients. The test materials and protocols are freely available online.
Protocols for intraoperative language mapping with direct electrical stimulation (DES) often include various language tasks triggering both nouns and verbs in sentences. Such protocols are not readily available for navigated transcranial magnetic stimulation (nTMS), where only single word object naming is generally used. Here, we present the development, norming, and standardization of the verb and noun test for peri-operative testing (VAN-POP) that measures language skills more extensively.
The VAN-POP tests noun and verb retrieval in sentence context. Items are marked and balanced for several linguistic factors known to influence word retrieval. The VAN-POP was administered in English, German, and Dutch under conditions that are used for nTMS and DES paradigms. For each language, 30 speakers were tested.
At least 50 items per task per language were named fluently and reached a high naming agreement.
The protocol proved to be suitable for pre- and intraoperative language mapping with nTMS and DES.