*4.3.2 Functional brain MRI (fMRI)*

The functional MRI acquisitions are based on the blood oxygen level dependent (BOLD), the main target is to confirm language hemisphere dominance in patients that are candidates for possible temporal lobe resection. It has been widely used in the context of pre-surgical evaluation in refractory seizure, is a noninvasive procedure, and is able to provide more precise localization and more cost-effective than the invasive Wada Test (with intracarotid amobarbital injection [25]. According to the American Academy of Neurology, fMRI, it is part of the guideline for language and memory function and should be predicting postoperative verbal memory outcome [37]. It can be also used in mapping of primary motor, somatosensory cortex, or

visual cortex, which is useful for certain tumors, gliosis, or focal cortical dysplasia, with close relationship to eloquent area [31]. EEG-fMRI may yield complementary information within the pre-surgical evaluation for patients with possible surgical treatment [36].
