Mapping and anatomo-surgical techniques for language preservation in brain tumours (Review).

Glioma resection surgeries require balance between language functioning protection and maximal tumour removal. Surgical planning is key for the success of resection procedures and the techniques involved are often associated with cortical mapping and tissue differentiation. These techniques include direct electrical stimulation, stereo-electroencephalography, functional magnetic resonance imaging, diffusion tensor imaging, functional ultrasound, hyperspectral imaging and intraoperative optical imaging. The present review explores the anatomical features of language-eloquent areas and the techniques and technologies developed to map cortical areas and distinguish tumour tissue from functional tissue. The benefits and limitations of each technique are discussed, along with their intraoperative and preoperative uses. All techniques are discussed in the context of their effectiveness in the preservation of cortical areas responsible for language processing.