Longnecker's Anesthesiology > Part 4. Managing Anesthesia Care > Section A. Monitoring the Anesthesia Patient > Chapter 32. Intraoperative Neurologic Monitoring John C. Keifer, MD, and Cecil O. Borel, MD

Key Points

"1. Anesthetic strategies to enhance intraoperative monitoring of the nervous system include techniques that minimize interference with neurophysiologic modalities as well as techniques that preserve neurocognitive function during structure and function mapping in the awake patient.

2. The cellular basis of a normal electroencephalogram (EEG) reveals a variety of pathways that produce alterations of electrical and neurocognitive function.

3. Synchronous EEG is seen with sleep, sedation and anesthesia, and cerebral ischemia.

4. Processed EEG algorithms can aid with objective assessment of EEG changes. Given an understanding of the EEG features analyzed by these algorithms, pitfalls leading to inaccurate assessment can be avoided.

5. Achieving reliability with evoked potential monitoring depends on minimizing anesthetic effect, maintaining a constant anesthetic level, and assuring adequate nervous tissue perfusion.

6. Intraoperative wakefulness for cortical mapping has been achieved by a variety of techniques. For a procedure to be successful, any techniques used must address the maintenance of effective ventilation during craniotomy and a balance of clear sensorium and sufficient analgesia to enable effective patient participation during cortical mapping.

7. Subarachnoid block for placement of epidural..."