Resting State functional MRI (rs-fMRI) is a relatively new type of test that locates all of the major brain networks.  Many major epilepsy centers are using this tool primarily for research in determining if it can help locate where seizures come from in the brain, whereas only a few are using it as part of mainstream clinical evaluation in epilepsy.  Only a single study in HH using rs-fMRI showed it was helpful in localizing where in HH the seizures came from and improved surgical outcomes (  Thus, the evidence is considered preliminary and such expertise is not expected to be available at most centers.