Preoperative Repetitive Navigated TMS and Functional White Matter Tractography in a Bilingual Patient with a Brain Tumor in Wernike Area

Abstract

Awake surgery and intraoperative neuromonitoring represent the gold standard for surgery of lesion located in language-eloquent areas of the dominant hemisphere, enabling the maximal safe resection while preserving language function. Nevertheless, this functional mapping is invasive; it can be executed only during surgery and in selected patients. Moreover, the number of neuro-oncological bilingual patients is constantly growing, and performing awake surgery in this group of patients can be difficult. In this scenario, the application of accurate, repeatable and non-invasive preoperative mapping procedures is needed, in order to define the anatomical distribution of both languages. Repetitive navigated transcranial magnetic stimulation (rnTMS) associated with functional subcortical fiber tracking (nTMS-based DTI-FT) represents a promising and comprehensive mapping tool to display language pathway and function reorganization in neurosurgical patients. Herein we report a case of a bilingual patient affected by brain tumor in the left temporal lobe, who underwent rnTMS mapping for both languages (Romanian and Italian), disclosing the true eloquence of the anterior part of the lesion in both tests. After surgery, language abilities were intact at follow-up in both languages. This case represents a preliminary application of nTMS-based DTI-FT in neurosurgery for brain tumor in eloquent areas in a bilingual patient.

Cortical Location of Language Function May Differ between Languages While White Matter Pathways Are Similar in Brain Lesion Patients

“…Furthermore, although the object-naming task used in the present cohort is used by multiple users [ 25 , 42 , 44 , 45 , 46 , 47 ] and, among others, still standardly used for intraoperative procedures by multiple departments [ 48 , 49 , 50 ], there is no standardization of the task, nor for perioperative test materials for all languages of patients included in the present study. This fact might particularly impact the number of false positives.…”

“…After the resting motor threshold was identified, the patient performed object naming [ 42 ]. The object-naming task used in the present cohort is implemented within the nTMS software and used by multiple users [ 25 , 42 , 44 , 45 , 46 , 47 ]. Furthermore, the object-naming task is, among others, still standardly used for intraoperative procedures by multiple departments [ 1 , 48 , 49 , 50 ].…”

Preoperative Navigated Transcranial Magnetic Stimulation: New Insight for Brain Tumor-Related Language Mapping

“…Since white matter damage can lead to a permanent language deficit [ 10 ], the addition of DTI-FT has been proposed to investigate the subcortical features of language, such as the AF [ 61 ], and the language pathway in bilingual patients [ 55 ]. In particular, the rnTMS-based DTI-FT protocol can reveal information on individual risk assessment for surgery-related decline in language function [ 74 ].…”

“…As previously explained, DTI-FT is used to study the subcortical white matter and single traits relevant for language function. The results showed convergence in the posterior areas of the first and second language pathways, an overlap that was interpreted in light of the patient’s high second language proficiency, as demonstrated by a neuropsychological assessment [ 55 ].…”

Current Status of Neuromodulation-Induced Cortical Prehabilitation and Considerations for Treatment Pathways in Lower-Grade Glioma Surgery

“…With compelling spatial resolution for the accurate localisation of eloquent cortical topography, nTMS has also been used to map facial recognition [120], visuospatial attention [121][122][123], disorders of consciousness [124] and bilingual language localisation [125]. It has also proven to be a useful clinical tool for the non-invasive mapping of resulting plasticity following revision brain tumour surgery [126,127], which may present therapeutic opportunities relating to how the brain is capable of reorganising itself in combination with data generated via DCS.…”