Interventional neuroradiology, sometimes requiring full anesthesia, is now performed in high-risk patients. The neurologic state of an anesthetized patient cannot always be sufficiently evaluated during the neuroradiologic examination. In such cases neurophysiological methods provide information about some aspects of the patient's cerebral condition. Three useful neurophysiological methods for monitoring hemispheric or brainstem functions during the neuroradiologic procedure are on-line or Fourier-transformed electroencephalographic (EEG) analysis; the monitoring of somatosensory-evoked potentials; and the monitoring of brainstem acoustic-evoked potentials. All methods can be done in the operating room with small, mobile equipment.
