MEP Changes Due to Cage Placement in ACDF Procedure
By Admin | March 01, 2023
As was the case with this 52-year-old patient, vertebral disc degeneration can be especially painful. In her case, cervical disc degeneration at C4-5 and C5-6 caused a lack of cushioning between vertebrae which meant spinal cord and nerve root pressure. As an additional layer of complexity, this wear and tear led to radiculopathy.
That pinched nerve feeling is a sharp burning pain and has the likely potential for traveling to other parts of the body connected to that nerve. And that was this patient’s experience: neck pain, the sharp burning of radiculopathy, and pain radiating to the left upper extremities.
The goal of a cervical discectomy and fusion (ACDF) is to remove those degenerative discs and replace them with a graft or cage. This replacement prevents the disc space from collapsing and allows the vertebrae above and below to fuse together, alleviating pain and allowing the patient to heal.
As is the delicate nature of surgery, particularly when the spinal cord and nerves are involved, there is always a possibility for post-operative complications. In the case of ACDF, that can mean many things, specifically deficits in motor function. The introduction of neuromonitoring into procedures like this one can significantly improve patient outcomes and provide surgeons with more data and information in the operating room.
For this patient’s cervical discectomy and fusion, somatosensory evoked potentials (SSEPs), motor evoked potentials (MEP), electromyography (EMG), train-of-four (TOF/TO4), and recurrent laryngeal nerve monitoring were all employed for this procedure. As the surgery began and baselines were established for each piece of neuromonitoring equipment, reproducible and reliable measures were confirmed from the bilateral FCU/FCR and APB/ADM. However, while the left MEP remained at baseline after the metal cage was placed, the motor evoked potentials on the right side flatlined.
Because this technology was present, the surgeon was informed immediately. After pulling the cage, reinserting, and adjusting it, the MEP slowly recovered above alert criteria. By the end of the procedure, the MEPs had essentially returned to baseline and the patient woke in the post-anesthesia care unit able to move all extremities by request, with no complaints noted.
Motor evoked potentials (MEP) are important for monitoring the descending or motor pathway and without them and neuromonitoring in general being utilized for this procedure, the patient may have suffered motor deficits as a direct result of the placement of the cage.
Axis Neuromonitoring provides high-quality intraoperative neurophysiological monitoring (IONM). For more information about neuromonitoring and how our practices create the best patient outcomes, call 888-344-2947 or visit https://www.axisneuromonitoring.com.
