Intraoperative Neuromonitoring

Intraoperative neuromonitoring is an early-warning system for the nervous system during spine surgery. While you are asleep, a specialist technician continuously measures the electrical function of your spinal cord and nerves and watches for any change. If the signals begin to alter — a sign a nerve or the cord is under strain — the team is alerted immediately, often before any lasting harm can occur, so the surgeon can adjust what they are doing. It is used particularly in operations that carry a higher risk to the nervous system, such as deformity correction, tumour surgery, and work close to the spinal cord.

• People having deformity correction (such as scoliosis surgery), where the cord is stretched or realigned
• People having surgery near the spinal cord, tumours, or complex or revision procedures
• People having fusions where screw placement is close to nerve roots
• Its use is decided by the surgeon according to the risk profile of the operation

• Small electrodes are placed on the scalp and on the muscles and skin of the limbs before surgery. Several types of signal are monitored together. Somatosensory evoked potentials test the sensory pathways carrying signals up the cord; motor evoked potentials test the motor pathways carrying signals down to the muscles; and electromyography listens for irritation of individual nerve roots, for example when a screw is being placed nearby. The technician and the surgeon watch these signals throughout, and any significant change prompts an immediate check — repositioning, pausing, or altering the surgical step — to protect the nerves.

• Continuous, real-time feedback on the health of the spinal cord and nerves
• Early warning of a developing problem, often before it becomes permanent
• Allows the surgeon to change course promptly to protect neurological function
• Adds a layer of safety to higher-risk operations

• The monitoring itself is very low risk; occasional minor effects include tongue or lip bruising from muscle twitches during motor testing
• It requires specific anaesthetic techniques, which the anaesthetist coordinates
• No system is perfect; monitoring reduces but cannot entirely eliminate the risk of nerve injury
• It is an adjunct that supports, rather than replaces, careful surgical technique

• Surgery without formal monitoring, relying on anatomy and technique, where the risk is low
• A "wake-up test" in selected deformity cases (now largely superseded by continuous monitoring)

Neuromonitoring does not change your recovery from the operation itself; its purpose is to protect neurological function during surgery so that you wake with your nerves working as well as possible. Your surgeon and anaesthetist will explain whether it is planned for your procedure.

• —British Association of Spine Surgeons (BASS)
• —Royal College of Anaesthetists — Guidelines and Standards
• —NICE — Interventional Procedures Guidance (relevant procedures)

This information is for general patient education and is not a substitute for an individual consultation. Always seek personalised advice from a qualified spinal specialist.