Intraoperative Neuromonitoring (IONM) provides surgical teams with real-time data that reduces the risk of neural injury during complex surgeries. It’s a game-changer in neurosurgery, especially during critical operations that involve the brainstem or spine. Because the margin for error in these surgeries is razor-thin, real-time feedback is absolutely essential. IONM provides an extra layer of safety for surgeons, reduces risk, and improves outcomes for patients.
In the following case study of a 25-year old patient with a brain tumor, SpecialtyCare’s IONM proved to be effective for preserving the patient’s neural function while the tumor was removed, and the surgery drastically improved his condition and alleviated his symptoms. The surgery, led by Dr. Wenya Linda Bi, Associate Professor of Neurosurgery at Mass General Brigham, Harvard Medical School, drastically improved the patient’s condition and alleviated his symptoms.
IONM Case Study: A 25-Year Old Patient with a Brain Tumor Increasing in Complexity
When it comes to brainstem surgery in particular, surgeons are working within extremely compact anatomy containing vital tracts, cranial nerves, and nuclei. Precision and accuracy are essential to a successful surgery. IONM offers dynamic, in-the-moment data that surgeons need to protect neurological function so that the best possible outcomes can be realized.
In this case, Dr. Bi performed a delicate resection on a 25-year-old male patient with a benign but recurrent pilocytic astrocytoma. The patient had been experiencing an increase in symptoms, including mild weakness on one side and double vision caused by nerve compression.
The tumor, first discovered when the patient was three years old, had expanded from the midbrain to the pons, pressing against the corticospinal tract. Because the tumor had increased in both size and complexity, surgical intervention was necessary. However, the risks were significant: potential facial numbness or paralysis, worsening weakness or double vision, or complications such as stroke, cerebrospinal fluid leakage, or buildup.
The IONM Process and Surgical Results
The IONM process began with preoperative planning and brain imaging. Advanced imaging showed how the corticospinal tract had shifted from posterolateral to encasing the tumor. It also provided insights on the anatomy and involvement of the tumor, helping to inform the surgical strategy.
IONM modalities were used to keep a pulse on nerve function, including transcranial MEPs, which monitored extremity muscles; cortically stimulated MEPs for facial, oculomotor, abducens, masseter muscles; subcortical motor mapping via monopolar stimulating suction; and SSEPs and brainstem auditory evoked potentials for sensory and cranial nerve monitoring.
Dr. Bi was able to remove the tumor in stages, checking the proximity to nerve pathways in real time through IONM. When low levels of current caused muscle responses, the surgeon could tell that the instruments were less than 1mm away from key nerve tracts. Blood vessels were preserved, and bleeding was controlled through the use of fibrin glue, reducing the risk of stroke or nerve damage. The MEPs and SSEPs did not deteriorate, indicating that facial and eye movement nerves remained responsive and intact.
The patient had a positive outcome. His double vision resolved, and MRI scans showed stability after the tumor’s removal.
To learn more about this procedure click the video below:
Get IONM Support for Complex Surgeries
At SpecialtyCare, our mission is to make surgery safer. That’s why we’ve become experts in IONM, supporting surgical teams across the country to reduce risks and improve outcomes for complex surgeries. We are the largest provider of IONM in the US, serving over 115,000 patients every year. Our extensive experience and high standards can help you continue to provide the best possible care to patients who need surgical intervention for neurological conditions. Contact us today to learn more about how we can support your hospital with IONM services!
About Dr Wenya Linda Bi
Dr. Wenya Linda Bi is Associate Professor of Neurosurgery at Mass General Brigham, Harvard Medical School in Boston, USA. She is the Director of the Skull Base and Microneurosurgery Fellowship, and Brigham site Program Director of the MGB Neurosurgery Residency. Her clinical expertise in skull base and deep-seated brain tumor surgery has been honored as a national Top Doctor for multiple consecutive years and the Brigham Distinguished Clinician award. In addition, she also leads a research team focusing on the translational biology of skull base tumors and refining intraoperative neuromonitoring techniques. A central driver across her efforts is to translate knowledge from advanced technologies to be transparent, scalable, and broadly accessible.
