ABSTRACT
Neurosurgical practice underwent a revolution in the 1970s with the advent of detailed anatomical imaging by computed tomography (CT), further improved by magnetic resonance imaging in the 1980s. Prior to CT nervous system pathology (tumors, bleeds, strokes, etc.) were localized indirectly by neurological findings and by the shifts of shadows on X-ray studies such as angiograms and pneumoencephalograms. Functional imaging technologies offer the possibility of an enhanced roadmap for safe surgical approach. The increase of cortical blood flow associated with functional “work” had been documented in animal models and inferred in humans by 1930. Electrocorticography and electrocortical stimulation (ECS) are commonly used intraoperative techniques for mapping and monitoring neurological function during surgery. ECS is an invasive mapping technique wherein an alternating current is applied directly to the cortex in either an awake or minimally sedated patient under local anesthesia. The intracarotid amobarbital test, or Wada test, is a technique originally designed to determine laterality of language function.
