The Role of White Matter Tracts in Language Status in Patients with Brain Tumors

Recent results of clinical studies have shown that speech function involves in its work not only fixed areas of the cerebral cortex but a complex system of connections that consists of different cortical regions connected by tracts. However, until now the roles of individual white matter tracts in various speech processes have not been fully studied. In this paper, we compare the integrity indicators (the volume) of three conducting tracts in the left hemisphere before and after surgery with the profile of speech disorders that occurred after the operation. The white matter tracts that have been studied are the arcuate fasciculus, the inferior longitudinal fasciculus, and the frontal aslant tract. The study was performed in a group of ten patients with brain tumors (low-grade gliomas). In this paper, a detailed analysis of diffusion tensor imaging (DTI) data of patients before and after the surgery is described. The obtained results are compared with the parameters of the speech function carried from the results of a standardized battery of linguistic tests RAT (Russian Aphasia Test). RAT has made it possible to identify the patient's speech disorders in order to subsequently compare the safety of each language level with the safety of the tracts. The obtained results will help to clarify and expand the existing models of the brain organization.