THE NEUROSURGEON’S PERSPECTIVE:
PROTECTING THE SPINAL CORD
Barth A. Green, M.D. • Alan D.O. Levi, M.D., Ph.D.
James Guest, M.D., Ph.D. • Blair Calancie, Ph.D.

Placement of instrumentation (metal rods and screws) to stabilize vertebrae can benefit patients with diseases or fractures that weaken the bones. Such surgical procedures, however, involve significant risk to the nerves of the spinal cord and its roots. Screws must be placed without damaging the nerves that pass between the bones. Misplacement can pose serious risks, such as muscle weakness or paralysis, sensory loss or increased pain. Drs. Calancie and Green report on a new method they developed for stimulating and monitoring nerve and muscle activity during surgery. The method uses repetitive transcranial stimulation and when applied in surgeries involving all levels of the spinal cord, it reduced the risk of nerve root damage.

Miami Project faculty members Drs. Green, Levi, and Guest carry out busy neurosurgical clinical practices while also conducting research. They publish important clinical findings to inform surgical colleagues of their experiences. Among this year’s reports is a retrospective study of their experience in treating post-traumatic syringomyelia, a condition that results in the formation of a fluid-filled cyst in the spinal cord. Cyst shunting is a common surgical approach to collapse the cyst. Historically, the long-term outcome of this approach has been discouraging. because of shunt failure Since the surgeons believe an underlying cause of cyst formation is tethering of the spinal cord to bone or soft tissue, they modified their treatment protocol. Before shunting the cyst, they untethered the spinal cord and used intraoperative ultrasound to evaluate the cyst. In 19 of 28 patients, untethering alone caused a significant collapse of the cyst. In those cases, they did not require shunting. As indicated from the results of this study, the surgeons feel this more logical approach to the problem may lead to a more favorable long-term outcome.