Case Studies - Spine Neurosurgery
The Neurosurgical Spine Service at Massachusetts General Hospital specializes in neurosurgical treatment of the entire spectrum of spine disorders, providing services from diagnosis through surgery and rehabilitation.
Neurophysiology Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
AbstractBACKGROUND AND IMPORTANCE: Reliable visual identification of the median raphae, essential for the preservation of function of the posterior dorsal columns during intramedullary spinal cord tumor resection, is not possible in many cases, because of distorted local anatomy. In such cases, intraoperative neurophysiologic mapping of the dorsal columns offers invaluable information to the surgeon, and guides the myelotomy. We hereby describe such a new technique.CLINICAL PRESENTATION: A 41-year-old man with a C3-C4 intramedullary spinal cord tumor underwent successful myelotomy and tumor resection. Dorsal column mapping was performed by use of an 8-contact minielectrode strip placed on the dorsal spinal cord. Direct electrical stimulation was applied via 2 adjacent contacts of the strip at a time, in an attempt to stimulate in succession the left and right dorsal columns. Somatosensory evoked potentials (SSEPs) were recorded after each stimulation, via scalp electrodes. A sharp change in polarity of the recorded scalp SSEPs (phase reversal) indicated when the stimulation of the opposite dorsal column occurred. Myelotomy was performed in between the minielectrode contacts identified as being situated closest to the raphe. The posterior tibial SSEPs were continuously monitored during and after myelotomy and until the dura closure. No changes from premyelotomy SSEPs were present. Postoperatively, the patient had preservation of the posterior column function.CONCLUSION: SSEP phase-reversal technique is a promising new method to identify the neurophysiologic midline in intramedullary tumor resection. Fast and easy to perform, its final role in neurophysiologic dorsal column mapping awaits confirmation in future applications.Neurosurgery. 2012 Mar;70(3):E783-8. doi: 10.1227/NEU.0b013e31822e0a76. - PMID: 21778916 [PubMed - indexed for MEDLINE]
Massachusetts General Hospital
Boston, Massachusetts 02114
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Cleveland Clinic Center for Spine Health, Cleveland Clinic, Cleveland, Ohio 44195, USA.
Central neurocytomas of the cervical spinal cord - report of two cases.
Neurosurgical Service, Massachusetts General Hospital, Boston.
- Central neurocytomas of the cervical spinal cord. Report of two cases. J Neurosurg 81:288-93.
- Recurrent central neurocytoma of the spinal cord (letter). J Neurosurg 82:184.
Left: Axial MRI image at C3-6. Note the separation of the tumor into lobules by the posterior median septum. T1-weighted image obtained after intravenous gadolinium.
Right Set: Sagittal MRI images. Left: T1-weighted. Right: T1-weighted with gadolinium
Intra-operative view after opening the dura posteriorly from the midline.
Note the tumor bulging in two lobules around the posterior median septum.
Cellular tumor with round nuclei and fibrillary nuclear free zones.
Hemotoxilin and eosin (H and E)