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.

Simon MV, Chiappa KH, Borges LF
Neurophysiology Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
BACKGROUND 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]

Lubelski D, Abdullah KG, Mroz TE, Shin JH, Alvin MD, Benzel EC, Steinmetz MP.
Cleveland Clinic Center for Spine Health, Cleveland Clinic, Cleveland, Ohio 44195, USA.
BACKGROUND: The lateral extracavitary approach (LECA) and costotransversectomy (CTE) are 2 dorsolateral approaches that avoid entrance into the pleural cavity and facilitate ventral decompression. The indications and outcomes of each of these approaches have not been fully defined in the literature.
OBJECTIVE: To assess the techniques, indications, and complications associated with the LECA and CTE approaches to the thoracic spine.
METHODS: A retrospective analysis was performed on all patients who underwent LECA and CTE between 2000 and 2009 at our institution.
RESULTS: A total of 54 patient charts were reviewed (19 LECA, 35 CTE). Indications for operation included disk herniation, trauma, tumor, osteomyelitis, and scoliosis/kyphosis. Osteomyelitis was treated significantly more often with LECA (47%) than with CTE (9%; P = .002). Mean blood loss was 2134 mL and 1556 mL (P = .3) in LECA and CTE, respectively, and hospital stay was 17.2 days for LECA and 9.8 days for CTE (P = .07). Thirteen LECA patients (68%) and 19 CTE patients (54%; P = 1.0) had preoperative or postoperative complications.
CONCLUSION: LECA was used more often to treat complex pathologies such as osteomyelitis and trended toward significance for more frequent use in extensive procedures involving 1- or 2-level corpectomies. As can be expected, CTE was associated with slightly less blood loss and a shorter hospital stay compared with the more extensive LECA operation. Adverse outcomes occurred with similar frequency for CTE and LECA.
Neurosurgery. 2012 Dec;71(6):1096-102. doi: 10.1227/NEU.0b013e3182706102. PMID: 22948200 [PubMed - in process]

Central neurocytomas of the cervical spinal cord - report of two cases.
Tatter SB, Borges LF, Louis DN

Neurosurgical Service, Massachusetts General Hospital, Boston.

Central neurocytoma is a neuronal neoplasm that occurs supratentorially in the lateral or third ventricles. The authors report the clinical, neuroradiological, and neuropathological features of two neurocytomas arising in the spinal cord of two men, aged 65 and 49 years. The patients presented with progressive neurological deficits referable to the cervical spinal cord. Magnetic resonance imaging revealed isodense intramedullary spinal cord tumors at the C3-4 level. Both tumors were initially misdiagnosed as gliomas. In Case 1 the correct diagnosis was made after electron microscopy revealed neuronal features. Immunostaining in Case 2 revealed that tumor cells were positive for synaptophysin and negative for glial fibrillary acidic protein, strongly indicating a neuronal tumor. It is suggested that this spinal cord neoplasm be included under the designation "central neurocytoma.
Neurocytomas Radiographic Neurocytomas Radiographic
Radiographic Appearance

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

Neurocytomas Intraoperative
Intraoperative Appearance

Intra-operative view after opening the dura posteriorly from the midline.

Note the tumor bulging in two lobules around the posterior median septum.

Neurocytomas Histology
Histological Appearance

Cellular tumor with round nuclei and fibrillary nuclear free zones.

Hemotoxilin and eosin (H and E)

J Neurosurg. 1994 Aug;81(2):288-93. Erratum in: J Neurosurg. 1995 Apr;82(4):706. PMID: 8027814 [PubMed - indexed for MEDLINE]

MGH Neurosurgical Service - Phone: 617-8581 - Massachusetts General Hospital - Fruit Street - Boston, Massachusetts 02114