Electromyography (EMG): Monitors Peripheral, Lumbar, and Cranial Nerves

Electromyography (EMG) is used during spine surgery to monitor the peripheral, lumbar, and cranial nerves. By monitoring the muscles which are stimulated by these nerves, our neural monitoring technologists can determine if a nerve root is being irritated or disturbed during the procedure. If a nerve root of the peripheral, lumbar, or cranial nerves is irritated in any way (bumping, stretching, etc.) during surgery, the nerve will depolarize, causing an action potential which in turn causes the corresponding muscle to twitch. The twitch is recorded by electrodes and immediate feedback is sent to our neural monitoring technologists.

Types of Surgeries that Use EMG Monitoring

Electromyography (EMG) is used in spinal surgeries. It is particularly recommended for all lumbar fusions and cervical fusions, as well as any other procedure wherein the peripheral, lumbar, and cranial nerves may be affected.

Electromyography is typically used to monitor the following:

Cranial nerves during:

• Skull base surgeries whenever the cranial nerves are at risk
• Microvascular decompression of the seventh or fifth cranial nerves
• Acoustic neuroma surgeries
• Parotid surgeries
• Surgery for middle ear revision
• Vestibular nerve sections

Peripheral nerves during:

• Peripheral neuroma surgeries
• Monitoring of femoral nerve function during anterior acetabular surgery

Spinal nerve roots during:

• Pedicle screw instrumentation surgeries
• Cauda equina surgeries

Advantages of EMG

EMG gives immediate feedback on both spontaneous and evoked electromyogenic activity, allowing our neural monitoring technologists to determine the status of the peripheral, lumbar, and cranial nerves. So, if a nerve root becomes irritated, the neural monitoring technologist will know immediately and can alert the surgeon in an effort to prevent a negative surgical outcome.

Disadvantages of EMG

EMG will not work effectively if the patient is taking medication that affects the nervous system, such as a muscle relaxant or anticholinergic (medicine used to reduce uncontrollable movements, relax the lung airways, and relieve cramps). In addition, even though an EMG will provide real-time feedback of nerve root irritation, sometimes the damage has already been done. Therefore, determining that a nerve was affected does not necessarily mean that it will lead to a more positive post-operative outcome.

If you are a surgeon or hospital in need of EMG monitoring or if you are a patient preparing for surgery, rest assured that Biotronic can provide the best protection possible when you need it most. Contact Biotronic today to learn more about how we protect the peripheral, lumbar, and cranial nerves through EMG monitoring or to find out about the other services we offer.