Intraoperative Neuromonitoring

Cortical tumors may by situated at or near important cortical centers such as those responsible for motor function, speech, and perception of sensations.  Safe resection of such tumors, without compromising cortical function, can be done with the use of cortical mapping.  Cortical mapping also guides the extent of tumor resection, which is directly linked to survival rate.

Cerebellopontine angle tumors arise from the brainstem where several cranial nerves arise.  Those cranial nerves are responsible for facial sensation and movement, hearing, swallowing,  moving one's vocal cords and tongue.  Those cranial nerves are highly at risk of injury during surgeries attempting the removal of CPA tumors.  Continuous monitoring of those nerves during surgery helps the surgeon accurately locate those nerves, as well as continuously monitor their function, thus providing safer surgery.

The brainstem contains the pathways for motor snd sensory functions for the entire body, as well as the auditory pathway.  It also contains the nuclei for all cranial nerves.  Monitoring of the brainstem functions during surgery is vital for patient safety.

Surgery addressing spine deformities is a frequent type of surgery performed in adolescents and adults. Neurological complications may result from such surgeries, including partial or total paraplegia, quadriplegia, or positional injuries.  Also, before IOM was available in the late 1970s, the wake-up test was used to ensure whether the patient can move their legs after correction, but before the end of surgery.  This was done by waking the patient up during surgery and asking them to move their legs, feet, and toes while they are laying face down on the surgical table, then putting them back to sleep.

Removal of spinal cord tumors has the risk of injuring the spinal cord which hosts the main pathways for movement and sensations of both upper and lower limbs.  Surgery involving the lumbosacral plexus poses similar risks to the motor & sensory functions, but additionally directly involves sphincter functions. IOM helps reduce the risk of injury of those pathways and of the lumbosacral plexus, helping preserve motor, sensory & sphincteric functions, as well as helping the surgeon make delicate decisions during surgery.

Spastic diplegic cerebral palsy (CP) is the most common form of CP. Selective dorsal rhizotomy (SDR) is a neurosurgical procedure that permanently reduces lower limb spasticity in children with spastic diplegic CP. Intraoperative electromyography (EMG) aids in  the identification and selection of the nerve roots to be sectioned. In carefully selected children, reduction in spasticity has positive effects on the growing child. SDR is associated with minimal complications and good long-term outcomes.

The risk of injuring the recurrent laryngeal nerve(s)  ( the nerves that supply each vocal cord) during surgeries involving the thyroid gland is about 50%.  Continuous monitoring of those nerves reduces that risk dramatically, offering patients who will undergo such surgeries the ability to preserve their vocal cord functions and undergo such procedures safely.

Some ENT (ear, nose & throat) procedures risk the safety of the facial nerve, while other, more complex procedures, almost always end up injuring the nerves responsible for eye movements as well as the facial and trigeminal nerves (responsible for facial movements and sensation).  Such risks are easily eliminated by using intraoperative neuromonitoring during those surgeries.  Moreover, IOM reduces the time of surgery and helps the surgeon operate with confidence.

For cranial nerves, brachial & lumbosacral plexus, pedicle screw stimulation