Intraoperative neurophysiologic monitoring (IONM) uses electrophysiological techniques to assess the integrity of the nervous system in patients undergoing surgery where there is a risk for iatrogenic damage. IONM includes EEG, EMG, basal ganglia microelectrode recording (MER) and several types of evoked potentials to measure nervous system function during surgery. While surgical damage to the nervous system is rare, these types of injuries can be devastating for patients and families as well as costly to the healthcare system.

We have been successfully using these techniques for 20 years and the Health Sciences Centre is a Canadian leader in this valuable patient safety program. IONM is included in complex surgeries of the spine (e.g. deformity corrections) as well as for pathologies involving the brainstem and eloquent brain areas (e.g. speech centres). IONM can be beneficial in operations involving the vasculature of the brain and spinal cord (e.g. cerebral aneurysms) by detecting ischemia (lack of oxygen). It is also extremely useful for Deep Brain Stimulation (DBS) to locate clinically effective targets for electrode implantation and minimize stimulation-related side effects.