Neuroimaging for patient selection for medial temporal lobe epilepsy surgery: Part 2 functional neuroimaging

•We evaluate functional MRI, positron emission tomorgraphy and single photon emission computed tomography scans in preoperative evaluation of medial temporal lobe epilepsy.•Used alone or in combination with other functional or structural imaging methods, these studies improve precision in localization of the epileptogenic region and language and memory lateralization.•This results in better postoperative results and minimal postoperative neurological deficits.

We evaluate and discuss the various functional imaging techniques that are currently in use to assess the eligibility of a refractory temporal lobe epilepsy (TLE) patient for treatment with medial temporal lobe surgery. The assessment of eligibility for treatment is challenging and relies heavily on functional imaging modalities that provide physiological information, in addition to structural data acquired by different imaging techniques. This review is the final segment of a two part study, the first of which focused on the structural and anatomical imaging modalities that are in use for the surgical treatment of TLE. The authors performed a comprehensive query of PubMed, Embase and Medline databases in search of all relevant English language studies that were published between 1990 and 2013. Overall, 56 papers were reviewed (50% of them covering primarily functional neuroimaging), including a total of 1517 patients. The extracted data included the general study identification, demographics, population, study design, neuroimaging methods, reference standard imaging method used (gold standard), outcomes, and conclusions. As the majority of the studies investigated functional MRI, single photon emission computed tomography and positron emission tomography, the authors focus the review on these specific modalities.