This case involves a 61-year-old female patient who underwent surgery to resect an intradural intramedullary spinal tumor. The surgical procedure included the use of intraoperative neurophysiological monitoring. As part of the IOM, both somatosensory evoked potentials and motor evoked potentials were monitored and recorded. During the surgery, the somatosensory evoked potential (SSEP) monitoring showed poor SSEP at the early stages. At the stage that the dorsal columns were split, the SSEPs became completely lost. The motor evoked potentials (MEPs) were initially stable, but the tibial MEPs were lost shortly after manipulation of the tumor began. The MEPs on the right came back and then dropped again as the surgery carried on and did not recover for the remainder of the surgery. Despite the loss of the SSEPs and the right side MEPs, the surgeon continued completed the full resection of the ependymoma tumor without performing a wake-up test. As a result of the surgery, the patient was rendered a permanently paraplegic.
Question(s) For Expert Witness
- 1. How often do you perform this type of surgery?
- 2. In general, what steps should be taken when SSEPS and MEPs are lost?
Expert Witness Response E-157319
This is a potentially life-threatening disease that if untreated will make you paraplegic or kill you. There is no place for stopping a surgery for an intramedullary spinal cord tumor. Evoked potential monitoring is affected by many things, which serve merely as a guide and are frequently unreliable. A surgeon needs to contextually assess the validity of the information they provide, as they are frequently wrong and frequently disappear for technical or anesthesia-related reasons. It would be totally inappropriate to stop an operation like this. In fact, it would be a breach of the standard of care to stop and do a wake-up test — not only because it would not be practical, but because it could be dangerous. Being paraplegic is both a risk of this surgery and of the natural history of this disease. This is not elective deformity surgery, it is tumor surgery in which the dura is opened and the spinal cord is exposed. Paraplegia sadly is a risk of this type of intervention, which is performed only with the goal of saving the patient’s life.