Intraoperative Neurophysiological Monitoring (IONM) for Lumbar Spinal Stenosis
December 07, 2020
Our connection to the world around us exists in a delicate bundle of nerves sheathed by a protective column of bone. The canal that guards this communication superhighway channel it down the length of the back, feeding and receiving information to and from every corner of our bodies. What happens when this continuum of densely packed nerves is disrupted, when the channel that houses our spinal cord and is designed to protect it, is the same thing that obstructs it?
Spinal stenosis is a narrowing of the open spaces in the spine, placing an unnatural level of pressure on the spinal cord and nerves that run through it. Usually a result of years of wear and tear or injury, patients can experience pain, muscle weakness, and numbness. For one 33-year-old, this was just another notch in a belt of medical troubles.
Already suffering from trigeminal neuralgia, depression, anxiety, PTSD, esophageal reflux, insomnia, migraine headaches, snoring, pneumonia, bowel disorders, acid reflux, urinary incontinence, obesity, Cushing’s disease, and hypertension, the pain was no stranger to this patient. In fact, it was probably what they knew best. Lumbar spinal stenosis left this patient living with agonizing hip and back pain, on top of neurogenic claudication and the mechanical complications of implanted orthopedic devices.
Both a Transforaminal Lumbar Interbody Fusion (TLIF) at the level of L3-S1 and a Posterior Lumbar Interbody Fusion (PLIF) at L2 were necessary for treatment. In conducting a PLIF, the spine is approached through a three-inch to a six-inch-long incision. Next, the left and right lower back muscles are stripped off the lamina and the lamina is subsequently removed. This allows for the surgical visualization of the nerve roots. To give the nerve roots more room, the facet joints are undercut and trimmed down and the site is cleaned of the disc material. A metal cage filled with allograft bone is then inserted into the disc space. A TLIF was used to remove the vertebral disc at L3-S1 and implant a graft in order to create a solid bone structure, eliminating movement between them once separated bone tissue to alleviate pain.
“We value the relationships we have fostered with our hospital and surgeon clients and respect the trust they have placed in us to see the job done correctly,” said Dr. Faisal R. Jahangiri of AXIS Neuromonitoring in Richardson, Texas.
Spinal surgeries are dangerous. Due to proximity to the spinal cord and the potential for complications, Axis intraoperative neurophysiological monitoring (IONM) was utilized to monitor the integrity of nerves and neurological responses for this patient. Intraoperative Neurophysiological Monitoring (IONM) by the Axis team allowed the performing surgeon to better identify risk and protect the neural structures exposed during surgery. For this 33-year-old patient, upper and lower Somatosensory Evoked Potentials (SSEP), lower Electromyography (EMG), Electroencephalography (EEG), and Train of Four (TOF) sensors were used. “Intraoperative neurophysiological monitoring assists surgeons in achieving the best outcomes for patients by utilizing real-time testing of nerve functions,” said Dr. Faisal R. Jahangiri.
During surgery, the SSEP data showed a transient loss in the signal from the bilateral posterior tibial nerves and peroneal nerves. The surgeon was informed and after intervention and repositioning, both the bilateral posterior tibial nerve and left peroneal nerve returned to baseline. As a result, no neurological deficits were noted postoperatively.
“Intraoperative sensory changes in the SSEP could not have been identified without neuromonitoring. Improper positioning, ischemia, stretching, or compression of the nerves could have resulted in a lumbosacral plexus injury, which could have left the patient with postoperative numbness, severe pain, burning sensations, muscle weakness, or foot drop,”Dr. Faisal R. Jahangiri commented.