Image-based functional neurosurgery.

The development of computerized tomography and compatible stereotactic frame and localization devices has improved the ease and accuracy of functional stereotactic neurosurgery. Computerized tomograph-directed functional stereotaxy appears to be a safe and effective means of target development. Magnetic resonance imaging holds the promise of greater anatomical definition and direct sagittal imaging. Significant questions remain, however, concerning the reliability of MRI-based stereotactic neurosurgery, and these must be addressed. Presently, these techniques should be viewed as a means to localize a target region, not the target per se, and, as stated by Apuzzo, "It is not envisioned, however, that the need for intraoperative stimulation will be mitigated by such refinements."