title: Cortical cartography reveals political and physical maps.
abstract: Advances in functional imaging have provided noninvasive techniques to probe brain organization of multiple constructs including language and memory. Because of high overall rates of agreements with older techniques, including Wada testing and cortical stimulation mapping (CSM), some have proposed that those approaches should be largely abandoned because of their invasiveness, and replaced with noninvasive functional imaging methods. High overall agreement, however, is based largely on concordant language lateralization in series dominated by cases of typical cerebral dominance. Advocating a universal switch from Wada testing and cortical stimulation mapping to functional magnetic resonance imaging (fMRI) or magnetoencephalography (MEG) ignores the differences in specific expertise across epilepsy centers, many of which often have greater skill with one approach rather than the other, and that Wada, CSM, fMRI, and MEG protocols vary across institutions resulting in different outcomes and reliability. Specific patient characteristics also affect whether Wada or CSM might influence surgical management, making it difficult to accept broad recommendations against currently useful clinical tools. Although the development of noninvasive techniques has diminished the frequency of more invasive approaches, advocating their use to replace Wada testing and CSM across all epilepsy surgery programs without consideration of the different skills, protocols, and expertise at any given center site is ill-advised.
authors.affiliation: Departments of Neurology and Pediatrics, Emory University, Atlanta, Georgia, U.S.A.
authors.forename: David W
authors.initials: DW
authors.lastname: Loring
authors.affiliation: Center for Neuroscience, Children's National Medical Center, Washington, District of Columbia, U.S.A.
authors.forename: William Davis
authors.initials: WD
authors.lastname: Gaillard
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, UCLA, Los Angeles, California, U.S.A.
authors.forename: Susan Y
authors.initials: SY
authors.lastname: Bookheimer
authors.affiliation: Department of Neurology & Neurological Sciences, Stanford University, Stanford, California, U.S.A.
authors.forename: Kimford J
authors.initials: KJ
authors.lastname: Meador
authors.affiliation: Department of Neurosurgery, Seattle Children's Hospital, Seattle, Washington, U.S.A.
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Ojemann
mesh_terms: D000654:Amobarbital; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000503:physiopathology*; D003399:Craniotomy / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D011300:Preoperative Care; D050781:Transcranial Magnetic Stimulation
chemical_list: D000654:Amobarbital
keywords: Cortical stimulation mapping; Magnetoencephalography; Wada testing; fMRI