First Project in Lab: EEG in IONM (pt. 2)

In this post I will continue my description of the first project that I worked on in the Pilitsis lab.

In the last post, I described the basics of spinal cord stimulation (SCS). After reading that post, you may be wondering how SCS is able to relieve pain in many different places in the body (e.g., back, low back, groin, legs, pelvis). The key factor in achieving significant pain relief through SCS is lead placement (where the SCS leads are placed in the body). But how do doctors know where to place these leads?

Previously, lead placement was determined by a sedation and waking approach. Patients would be sedated while the lead was placed, and then they would be woken up to assess pain relief. You can probably guess why this technique was not very effective. When lying on the operating table, there are a multitude of factors that could change the amount of pain a patient feels in that moment. Therefore, procedures that do not involve waking up the patient were developed.

Now, placing patients under general anesthesia and using intraoperative neuromonitoring (IONM) is utilized to determine accurate lead placement. Different forms of IONM track different things in the brain. The most popular forms of IONM used for lead placement are electromyography (EMG) and somatosensory evoked potential (SSEP). EMG tracks muscle responses while SSEP tracks responses to things like temperature, touch, and pain. EMG and SSEP are most accurate in determining ideal lead placement when used together.

A less common form of IONM utilized is electroencephalogram (EEG). EEG tracks brain waves. In this study, we asked the question, "What additions can EEG make to SSEP and EMG in IONM?" Therefore, we wanted to see if using EEG in addition to EMG and SSEP would result in an improved percentage of accurate lead placements for SCS. In this study, I worked on writing the cover letter, introduction, and methods. I worked closely with a medical student from Albany Medical College in revising the manuscript and reading up on SCS and IONM.