What Patients Should Know about IONM

IONM provides early warning to surgeons by providing real-time neurophysiological data during a patient’s procedure.

What is intraoperative neuromonitoring (IONM) and what can I expect before, during, and after surgery?

IONM is an integral part of many surgeries, including neurosurgery, orthopedic spine surgery, peripheral nerve surgery, vascular surgery, and otolaryngologic surgery. Any surgical procedure that involves your surgeon operating close to delicate nerves and their supporting vascular structures inherently places those structures at risk. IONM provides early warning to your surgeon by providing real-time neurophysiological data during your procedure. This data helps prevent or minimize potential surgical injury and post-operative deficits.

NuVasive Clinical Services (NCS) neurophysiologists and interpreting physicians are there to focus on your specific needs during the procedure. Having neurophysiologists in surgery facilitates effective communication among caregivers, helping improve recognition and response to changes in your neurophysiological status.

Learn more


Before Surgery

Wherever possible, just prior to surgery, your NCS neurophysiologist will meet with you and may perform a brief exam. At this time, you may ask your neurophysiologist questions about IONM. Your neurophysiologist will ask you to sign a consent and assignment of benefits form confirming your consent for IONM services and authorizing payment of insurance benefits to NCS. This form will also allow NCS to appeal or advocate on your behalf with your insurance company if needed. Note that if the form is not signed at time of surgery, you can expect to receive another assignment of benefits form in the mail after surgery for signature and return to NCS.

During Surgery

Once you have been given anesthesia, your NCS neurophysiologist will apply a series of sterilized subdermal (beneath the skin) electrodes and surface adhesive pad electrodes to various parts of your body. The placement of each electrode is very specific to the type of surgery that you will have. These electrodes transmit signals from your nervous system to a special computer that is being controlled by your neurophysiologist. The data captured by these electrodes is communicated by your neurophysiologist to your surgeon, in real time, during surgery. As an additional protective measure, NCS may provide a remote physician specializing in neurophysiologic monitoring to assist your neurophysiologist and interpret the IONM data.


A report will be generated by your NCS neurophysiologist (and oversight physician if applicable), which will become part of your medical record with your medical facility and/or surgeon’s office. There is little risk associated with IONM, but you may experience some minor bleeding, bruising, or muscle soreness from the subdermal electrodes; there is a minimal risk of unplanned injuries to the tongue, teeth, or lips.