WHAT TO EXPECT
BENEFITS OF MONITORING
Our intraoperative neuromonitoring (IOM) specialists work with your surgeon to see that your surgery is a success. Surgical monitoring offers a wealth of benefits:
Decreased risk of temporary or permanent neural damage
Increased surgeon confidence
Improved surgical outcomes
Decreased time in the operating room
Real-time monitoring by a remote physician
WHAT TO EXPECT THE DAY OF…
IOM FROM YOUR PERSPECTIVE
- On the day of your surgery, a National Neuromonitoring technologist will greet in the pre-operative holding room to review your health history, brief you on the monitoring procedure, and present you with a patient consent form.
- With the initial briefing finished, your technologist will place surface electrodes at specific locations on your ankles and wrists to monitor your nerve pathways during the surgery.
- Once you are under anesthesia and brought into the operating room, your technologist will place the necessary subdermal electrodes on various locations so they can conduct the appropriate intraoperative monitoring specific to your procedure. The electrodes are then connected to our equipment, and we begin monitoring your neural function before surgery begins.
- Throughout your surgical procedure, your technologist will run tests and communicate results to the surgeon. When your surgery is complete, your technologist will remove your electrodes before you wake up from anesthesia.
DEDICATED TO YOUR HEALTH
Our team provides monitoring for a variety of neurological, orthopedic, and cardiovascular surgical procedures. Each associated test is determined by the specific type of surgical procedure you are undergoing.
SPINAL
CRANIAL
EAR, NOSE & THROAT
PERIPHERAL
VASCULAR
SPINAL SURGERY DETAILS
Spinal Cord Tumors | Cervical Fusion | Lumbar Fusion | MITR | Kyphoplasty | Corpectomy | Rhizotomy | XLIF/TLIF/ALIF | SCS Implant | Thoracic Fusion | Spinal Deformity | Scoliosis Correction | Tethered Spinal Cord Release | Removal of Hardware
Most spinal procedures involve one or more of the following techniques:
1. Partial or complete removal of a vertebral disc and replacement with an artificial device
2. Decompression/removal of tissue that may be impinging on a nerve and causing pain
3. Stabilization of the spine through the placement of rods and screws to aid in healing
4. Stabilization of a fractured or unstable vertebral body by:
• Removing the fractured body and replacing the space with an artificial body
• Inserting a balloon into the vertebral body, inflating the balloon, and filling the fractured body with a cement-like substance
5. Severing of overactive nerve roots that may be causing neuromuscular spasticity problems
Spinal deformity cases vary and may require corrective action. Examples include straightening the spine using hooks, rods, and screws, or release of the spinal cord from attachment at the end of the spinal cord.
Intraoperative monitoring during these procedures informs the surgeon with respect to nerve irritation or damage that may be caused during surgery.
CRANIAL SURGERY DETAILS
Aneurysm | Acoustic Neuroma | Brain Tumors | Craniotomy | Chiari Malformation
Each of these procedures involves either tumor removal, nerve decompression, or arterial repair. The specific location of the tumor, nerve, or artery determines which structures and/or nerves are monitored and what tests are performed.
Monitoring helps the surgeon identify specific cranial nerves responsible for expression and sensation (hearing, sight, taste, etc.) with the goal of preserving, protecting, and avoiding them.
Because arteries are responsible for supplying oxygen to the brain, it’s vital that activity is monitored in areas of the brain that rely on blood supplied by the damaged artery. A decrease in activity can signify insufficient blood flow, causing the surgeon to take immediate corrective action.
ENT SURGERY DETAILS
Thyroidectomy | Cochlear Implant | Parotidectomy | Tympanomastoidectomy
Ear, nose, and throat (ENT) surgeries require surgeons to work near the facial nerve which controls movement around the eyes and lips. ENT surgeries also affect the recurrent laryngeal nerve, which facilitates speech. By carefully monitoring muscle activity in the facial muscles around the eyes and lips, IOM technologists can identify the nerves touched, stretched, or irritated during surgery. This decreases the likelihood of a patient experiencing a sore throat, scratchy voice, or loss of function of facial muscles after surgery.
PERIPHERAL SURGERY DETAILS
Acetabular Fractures | Total Hip Replacement and Revision | Total Shoulder Repair | Peripheral Nerve Exploration and Repair
During these procedures, peripheral nerves are at risk. This can be the result of direct surgical intervention or patient positioning. By monitoring the limbs and nerves at risk, preventative measures can be taken or issues can be identified and corrected.
VASCULAR SURGERY DETAILS
Carotid Endarterectomy | Cardiopulmonary Bypass | Aortic Aneurysm
In some vascular procedures, surgeons need to clamp an artery to remove plaque or repair a blood vessel. During time the artery is clamped, monitoring can quickly pinpoint when the brain, spinal cord, and peripheral nerves are not receiving sufficient oxygen. If needed, the surgeon can then place a shunt to restore blood flow to the area.
COMMON TESTS
Our team individualizes each test specific to your surgery. These tests allow us to monitor your nerve responses and facilitate real-time feedback.
➤
Somatosensory Evoked Potentials (SSEP)
Structures Monitored: The posterior sensory pathways of the spinal cord starting from the ends of the limbs, running up the spine and to the brain.
Surgeries Used On: Spinal, Cranial, Peripheral, Vascular
How the Test is Performed: Small amounts of current are applied at the patient’s wrists and ankles using small sticky electrodes. This causes the nerves to send electrical impulses along the sensory pathway all the way to the brain. Subdermal electrodes are placed under the skin along this nerve pathway to record the size of the impulse and how long it takes the impulse to travel. Finally, the impulse is recorded by electrodes at its final destination: the outer, top portion of the brain or the cortex.
Transcranial Electric Motor Evoked Potentials (TceMEP)
Structures Monitored: The anterior motor pathway of the spinal cord starting at the brain, running down the spinal cord and out to the muscles of the arms and legs.
Surgeries Used On: Spinal, Vascular
How the Test is Performed: Electrodes are placed on the top of the patient’s head to issue small amounts of current that travel down the spinal cord and continue to the hands and the feet, causing muscles to contract. Other electrodes are also placed on appropriate muscle groups in the arms or legs to read and record the electrical impulses and muscle reactions.
TRAIN OF FOUR (TOF)
Structures Monitored: This test assesses how much muscle relaxant a patient has in their system, and helps to determine when the muscle relaxant has worn off.
Surgeries Used On: Any procedure in which the IOM technologist needs to read the patient’s muscle activity in order to provide the surgeon with accurate information.
How the Test is Performed: Muscle activity is read and recorded by issuing a current through a subdermal electrode placed on one of the patient’s nerves, causing a muscle contraction.
Electromyography (EMG)
Structures Monitored: Any muscle group that is innervated by at-risk nerve roots.
Surgeries Used On: Spine, ENT, Cranial, Vascular
How the Test is Performed: Electrodes are placed on appropriate muscles to record all muscle activity in a patient.
➤
Triggered Electromyography (tEMG)
Structures Monitored: Any muscle group that is innervated by at-risk nerve roots.
Surgeries Used On: Spine, ENT, Cranial
How the Test is Performed: Electric current is used to stimulate the patient’s nerves so that responses can be recorded in the muscles. This ultimately assists in the placement of screws during spine surgery, helping to identify nerve roots, and testing nerve functionality.
Electroencephalography (EEG)
Structures Monitored: Brain Activity
Surgeries Used On: Spinal, Cranial, Vascular
How the Test is Performed: Recording electrodes are placed in various locations on the patient’s scalp to record the brain’s electrical activity and help identify changes in brain activity.
➤
Visual Evoked Potential (VEP)
Structures Monitored: Optic Pathway/Optic Nerve
Surgeries Used On: Various neurosurgical procedures
How the Test is Performed: Several electrodes are placed on the occipital lobe at the back of the patient’s head. A flash of a pattern stimulates the eyes and sends an impulse along the optic nerve, which is then recorded by the electrodes.
Brainstem Auditory Evoked Response (BAER)
Structures Monitored: The auditory pathway beginning at the outer ear, through the inner ear, up the brainstem and then recorded at the cortex.
Surgeries Used On: Cranial, ENT
How the Test is Performed: Using an audible click through an earphone or speaker, an impulse travels through the patient’s ear, up the brainstem and on to the outer part of the brain where it is recorded by electrodes that are placed on the scalp. This test allows the physician to stimulate and identify the nerve responsible for hearing in the auditory pathway.
Cortical Mapping and Language Mapping
Structures Monitored: Cortical mapping allows the physician to identify specific areas of the brain (language, motor cortex, sensory cortex) by stimulating the brain with an electric current and observing the body’s response.
Surgeries Used On: Cranial
How the Test is Performed: The physician stimulates certain areas of the patient’s brain and records limb muscle activity or patient language responses. The responses indicate which area of the brain was stimulated, and allow the physician to label the area accurately.
PHASE REVERSAL
Structures Monitored: Motor Cortex, Sensory Cortex and the Central Gyrus.
Surgeries Used On: Any cranial case where it is necessary for the physician to identify the location of the Central Gyrus.
How the Test is Performed: A grid strip with eight holes is placed along the patient’s brain in a front to back position over the motor cortex and the sensory cortex. While the physician uses a probe to stimulate the brain in each of the holes located along the grid strip, the IOM technologist observes the responses and records the results.