Functional MRI as a Valuable Non-Invasive Brain Mapping Technique in Healthy Subjects and Patients with Brain Tumors

"nIntroduction: Functional Magnetic Resonance Imaging (fMRI) plays a significant role in pre-neurosurgical planning at present. FMRI is a possible candidate to replace invasive methods for determination of language dominant hemisphere and cortical areas associated with language and memory. Also it is useful to determine critical sensory-motor areas of the cerebral cortex. We used this method to explore language and motor functions in healthy volunteers before creating standard paradigms for Persian language. In this study we use the standard protocol of language and motor brain mapping in patients harboring brain tumors. "nMaterials and Methods: 16 healthy right-handed Persian speaker volunteers and 8 patients with brain tumor were employed. Each subject performed five language related tasks during fMRI scan. These tasks include; Word Generation (WG), Object Naming(ON), and Word Reading (WR) selected from similar prior studies in other languages, and Word Production (WP) and Reverse Word Reading (RWR) as new proposed paradigms. Also 2 separate motor tasks were performed to delineate motor cerebral cortices. Fifteen continuous slices were acquired, and data analysis was carried out using FEAT 5.90 (Part of FMRIB's Software Library, www.fmrib.ox.ac.uk/fsl). After evaluating the individual results, the ability of each task to activate classical language and motor areas was assessed using group analysis. In addition, the lateralization index (LI) for each subject-task was calculated and compared. "nResults: We found that WP, RWR, and WG activate language related areas in dominant hemisphere robustly both in patients and in healthy subjects. However, ON and WR fail to delineate these activation areas optimally. In addition, the results reveal that higher activation intensities are obtained by WP in the frontal lobe including Broca’s area, whereas RWR leads to the highest LI among all examined tasks. Also motor tasks reveal a precise map of motor cortex in both groups. These results can be used to guide neurosurgeons in the surgical removal of brain tumors to minimize damage to critical cerebral areas. "nConclusion: This suggests that neural processing underlying Persian language is similar to other indo-European languages. This type of language evaluation may be used in pre-surgical planning of neurosurgical procedures in the Persian population. By using fMRI as a non-invasive tool we can demonstrate a precise functional brain map before surgery and use this map to prevent damage to language and motor related areas. This method of brain imaging safely lowers