Publications

Abstract

Background
Reliable language mappings require sufficient language skills. This study evaluated whether linguistic task properties impact feasibility and reliability of navigated transcranial magnetic stimulation (nTMS)-based language mappings in aphasic glioma patients.

Methods
The effect of linguistic complexity on naming accuracy during baseline testing without stimulation and on the number of errors during nTMS was evaluated for 16 moderately and 4 severely expressive aphasic patients.

Result
During baseline, items acquired later in life and used less frequently, a higher amount of multisyllabic, compound, and inanimate items were named inaccurately. Even after removing these more complex items, less frequent and multisyllabic items were more error-prone during stimulation.

Conclusion
Higher linguistic item complexity was associated with decreased naming accuracy during baseline and resulted in a potentially higher false positive rate during nTMS in aphasic glioma patients. Thus, tailoring task complexity to individual performance capabilities may considerably support the preservation of residual functionality.

Abstract

Gliomas are brain tumors infiltrating healthy cortical and subcortical areas that may host cognitive functions, such as language. If these areas are damaged during surgery, the patient might develop word retrieval or articulation problems. For this reason, many glioma patients are operated on awake, while their language functions are tested. For this practice, quite simple tests are used, for example, picture naming. This paper describes the process and timeline of picture naming (noun retrieval) and shows the timeline and localization of the distinguished stages. This is relevant information for presurgical language testing with navigated Magnetic Stimulation (nTMS). This novel technique allows us to identify cortical involved in the language production process and, thus, guides the neurosurgeon in how to approach and remove the tumor. We argue that not only nouns, but also verbs should be tested, since sentences are built around verbs, and sentences are what we use in daily life. This approach’s relevance is illustrated by two case studies of glioma patients.

Abstract

Background

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.
Methods

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.
Results

At least 50 items per task per language were named fluently and reached a high naming agreement.
Conclusion

The protocol proved to be suitable for pre- and intraoperative language mapping with nTMS and DES.