Cortical Mapping

Synonyms

Direct stimulation mapping; Electrical stimulation mapping (ESM); Functional mapping

Description

Cortical mapping is an invasive procedure in which electrical stimulation is applied briefly to the cortical surface for the purpose of identifying areas critical for sensory, motor, or language function. This procedure is utilized when brain surgery involves the removal or disruption of potentially functional cortical areas. Sites identified via cortical mapping are typically spared from resection, with the goal of preserving function postoperatively.

Stimulation is applied using a bipolar stimulator, usually via pairs of adjacent subdural electrodes. The procedure can be conducted intra-operatively in a conscious patient before resection of brain tissue, or extra-operatively, if subdural electrodes have been implanted, most commonly in pharmacologically resistant epilepsy patients who require intracranial EEG monitoring to delineate the region of seizure onset and spread (Fig. 1)...