How does neuromonitoring work?

Answered by Frank Schwing

Neuromonitoring is a fascinating technology that has revolutionized the field of surgery, particularly in procedures involving the spine. It provides surgeons with real-time feedback on the function of the spinal cord and its associated nerve roots, motor tracts, and sensory tracts during the course of a surgical procedure. This invaluable information allows the surgeon to make more informed decisions and take necessary precautions to minimize the risk of damage to the spinal cord and its surrounding structures.

The process of neuromonitoring begins with the placement of electrodes on various parts of the body, including the scalp, limbs, and sometimes directly on the spinal cord itself. These electrodes are connected to a monitoring system that records and analyzes the electrical signals generated by the nerves. This electrical activity is then relayed to the surgeon, who can interpret the information and assess the integrity of the spinal cord and its associated pathways.

One of the key components of neuromonitoring is the use of somatosensory evoked potentials (SSEPs). SSEPs measure the electrical responses generated in the sensory pathways of the spinal cord in response to stimulation of the peripheral nerves. By stimulating a specific nerve, such as the median nerve in the wrist, and recording the electrical responses at various points along the sensory pathway, any changes or abnormalities can be detected. This allows the surgeon to identify potential issues that may compromise the function of the sensory pathways and take appropriate action.

Another technique used in neuromonitoring is motor evoked potentials (MEPs). MEPs involve the stimulation of the motor cortex of the brain and recording the resulting electrical activity in the muscles. This provides information about the integrity of the motor pathways and helps the surgeon identify any potential damage or compromise to these pathways during surgery. By monitoring MEPs, the surgeon can make real-time adjustments to minimize the risk of motor deficits or paralysis.

In addition to SSEPs and MEPs, other techniques such as electromyography (EMG) and spontaneous electromyography (SEMG) may also be utilized in neuromonitoring. EMG involves the recording of the electrical activity of the muscles, which can provide valuable information about nerve function and integrity. SEMG, on the other hand, measures the spontaneous electrical activity of the muscles and can help detect any abnormal patterns that may indicate nerve injury or dysfunction.

Neuromonitoring is a sophisticated and highly valuable tool that allows surgeons to assess and protect the integrity of the spinal cord and its associated structures during surgery. By providing real-time feedback on nerve function, it enables surgeons to make informed decisions and take immediate action to prevent potential complications. It has greatly improved patient outcomes and safety in spinal surgeries, and continues to advance with new technological developments and refinements.