Cervical magnetic resonance imaging abnormalities not predictive of cervical spine instability in traumatically injured patients
Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004
Eric M. Horn, Gregory P. Lekovic, Iman Feiz-Erfan, Volker K. H. Sonntag and Nicholas Theodore
Object. Identifying instability of the cervical spine can be difficult in traumatically injured patients. The goal of this study was to determine whether cervical abnormalities demonstrated on magnetic resonance (MR) imaging are predictive of spinal instability.
Methods. Data in all patients admitted through the Level I trauma service at the authors' institution who had undergone cervical MR imaging were retrospectively reviewed. The reasons for MR imaging screening were neurological deficit, fracture, neck pain, and indeterminate clinical examination (for example, coma). Abnormal soft-tissue (prevertebral or paraspinal) findings on MR imaging were correlated with those revealed on computerized tomography (CT) scanning and plain and dynamic radiography to determine the presence/absence of cervical instability.
Of 6328 patients admitted through the trauma service, 314 underwent MR imaging of the cervical spine. Of 166 patients in whom CT scanning or radiography demonstrated normal findings, 70 had undergone MR imaging that revealed abnormal findings. Of these 70 patients, 23 underwent dynamic imaging, the findings of which were normal. In each case of cervical instability (65 patients) CT, radiographic, and MR imaging studies demonstrated abnormalities. Furthermore, there were 143 patients with abnormal CT or radiographic study findings, in 13 of whom MR imaging revealed normal findings. Six of the latter underwent dynamic testing, which demonstrated normal results.
Conclusions. Magnetic resonance imaging is sensitive to soft-tissue injuries of the cervical spine. When CT scanning and radiography detect no fractures or signs of instability, MR imaging does not help in determining cervical stability and may lead to unnecessary testing when not otherwise indicated.
Robert J. Weil, Alexander O. Vortmeyer, Zhengping Zhuang, Svetlana D. Pack, Nicholas Theodore, Robert K. Erickson and Edward H. Oldfield
✓ Hemangioblastomas of the central nervous system (CNS) may occur sporadically or in association with von Hippel—Lindau (VHL) syndrome. The authors present four patients with no family history or clinical evidence of VHL syndrome in whom extensive, progressive, en plaque coating of the brainstem and spinal cord with hemangioblastomas developed 1 to 8 years after complete resection of a solitary cerebellar hemangioblastoma.
Analysis included detailed physical, biochemical, radiological, and pathological examinations in all four patients, combined with family pedigree analysis. In addition, a detailed investigation of the VHL gene was undertaken. Allelic loss, comparative genomic hybridization (CGH), single-stranded conformational polymorphism screening, CpG island methylation status, and X chromosome inactivation clonality analyses were performed. Although there was no evidence of germline alterations in the VHL gene on clinical and radiological examination or in the family history (all four patients) or analysis of peripheral blood (three patients), somatic deletion of one copy of the VHL gene occurred in these tumors. These findings indicate that the multiple, separate deposits of tumors were likely derived from a single clone. Results of CGH indicate that one or several additional genes are probably involved in the malignant behavior of the hemangioblastomas in these patients. Furthermore, the malignant biological and clinical behavior of these tumors, in which multiple sites of subarachnoid dissemination developed 1 to 8 years after initial complete resection, followed by progressive tumor growth and death of the patients, occurred despite a histological appearance typical of benign hemangioblastomas.
Malignant hemangioblastomatosis developed 1 to 8 years after resection of an isolated cerebellar hemangioblastoma. Alterations of the VHL gene may be permissive in this setting, but other genes are likely to be the source of the novel biological and clinical presentation of the disseminated hemangioblastomas in these patients. This appears to represent a novel condition in which the product of one or more mutations in several genes permits malignant tumor behavior despite retention of a benign histological picture, a circumstance previously not recognized in CNS tumors.
Mohammed A. Eleraky, Nicholas Theodore, Mark Adams, Harold L. Rekate and Volker K. H. Sonntag
Object. To evaluate and review their experience with pediatric cervical injuries and factors affecting outcome, the authors conducted a retrospective clinical study of 102 cases (65% boys, 35% girls) of pediatric cervical spine injuries treated in the last decade. This study is an extension of and comparison with their earlier experience.
Methods. Patients were divided into two age groups—birth to 9 years (Group 1) and 10 to 16 years of age (Group 2)—and managed according to status at presentation and type of injury. Thirty patients were managed surgically and 72 nonsurgically (42 wore a halo brace and 30 wore hard collars or custom-molded braces).
Motor vehicle accidents were the most common cause of injury, and 40% were associated with head injury. Patients in the younger-age group (Group 1) sustained more neurological injuries than the older patients in Group 2, and most injuries were in the upper cervical spine. Of the 38 children in Group 1, in 39% a subluxation was present and in 29% a fracture or fracture/subluxation was demonstrated. Of the patients in Group 2, 80% had sustained fractures or fracture/subluxations. Vertebral fractures were the most common radiological findings (32%). At late follow-up review (mean 5 years), solid fusions were demonstrated in all patients. Neurological deterioration did not occur in any patient. The mortality rate was 16%. Compared with the authors' earlier report, the incidence of cases with pediatric cervical injuries increased, as did the number managed surgically. Various fusion techniques were used, and neurological and fusion outcomes improved as compared with the previous report.
Conclusions. The prognosis of neurological recovery from pediatric cervical spine injuries is related to the severity of the initial neurological injury. Management must be tailored to the patient's age, neurological status, and type and level of injury. Compared with our earlier experience, fusion and instrumentation procedures were used more frequently. Different types of fusion and instrumentation procedures can be performed safely in children and produce good outcomes.
R. John Hurlbert, Nicholas Theodore, Janine B. Drabier, Andrea M. Magwood and Volker K. H. Sonntag
Object. Pain control can often be improved by local (as opposed to systemic) application of analgesic and/or anesthetic medication. The purpose of this study was to evaluate the efficacy of a single-dose epidural analgesic “paste” in the control of postoperative pain in patients who have undergone lumbar decompressive surgery.
Methods. Sixty patients undergoing routine elective lumbar decompressive surgery were randomized in a double-blind fashion to one of two groups: those receiving active paste or placebo paste. The paste was applied to the exposed dura at the time of surgery, just prior to wound closure. Patients received follow-up care in the hospital and at home for 3 months postsurgery. Several outcome measures were studied to ascertain differences in pain control and to ensure comparability between groups. Patients who received active paste demonstrated significantly lower pain scores compared with those who received placebo paste for up to 6 weeks postoperatively. General health perception indexed by the Short Form 36 was also significantly better in patients who received active paste for up to 6 weeks. In-hospital and outpatient oral narcotic consumption was significantly lower in the active paste-treated group. Inpatient straight leg raising scores were improved in those patients who received active compared with control paste.
Conclusions. Application of an analgesic paste directly to the epidural space during lumbar decompressive surgery significantly improves postoperative pain control, reduces prescribed analgesic drug consumption, and improves overall health perception for up to 6 weeks following surgery. The authors conclude that this postoperative pain control strategy is both effective and safe and may provide a new standard of pain management in patients undergoing lumbar discectomy or laminectomy.
Case report and literature review
Paul D. Sawin, Nicholas Theodore and Harold L. Rekate
✓ Gangliogliomas of the spinal cord are rare disease entities that occur in early childhood. Their occurrence in association with neurofibromatosis Type 2 (NF2) has not been described. The authors describe the unique case of a 2-year-old child with stigmata of NF2 who harbored a spinal cord ganglioglioma that presented as a rapidly growing, exophytic intramedullary mass lesion at the cervicomedullary junction. Treatment consisted of complete surgical resection. Histopathological analysis of the lesion demonstrated a mixed population of neoplastic cells, of both neuronal and glial lineage, that supported the diagnosis of ganglioglioma.
Patrick P. Han, Nicholas Theodore, Randall W. Porter, Paul W. Detwiler, MichaeL T. Lawton and Robert F. Spetzler
✓ The authors report a patient in whom a subdural hematoma developed from a Type I spinal arteriovenous malformation (AVM). The patient became symptomatic with back pain, and magnetic resonance imaging revealed a spinal subdural hematoma. Selective spinal angiography, however, failed to demonstrate a pathological process. The patient underwent exploratory laminoplasty that revealed a subdural extraarachnoid hematoma with an underlying Type I spinal AVM, which was surgically obliterated. The patient recovered completely. Subdural hematomas that affect the spine are rare. Although a negative result was obtained using selective spinal angiography, exploratory surgery should be considered for the evacuation of a subdural hematoma and possibly for the definitive treatment of a spinal AVM.
Geun Sung Song, Nicholas Theodore, Curtis A. Dickman and Volker K. H. Sonntag
✓ Bilateral posterior C1–2 transfacet screw placement with associated posterior bone graft wiring is the accepted treatment for patients with atlantoaxial instability. This technique was modified to treat 19 patients with atlantoaxial instability and unilateral anomalies that prevented placement of a screw across the C1–2 facet. In these cases, a single contralateral transarticular screw was placed in conjunction with interspinous bone graft wiring to avoid neural or vertebral artery injury and to provide C1–2 stability. Postoperatively, all 19 patients were placed in Philadelphia collars (mean immobilization 8 weeks, range 6–12 weeks). Unilateral C1–2 facet screw fixation was needed for the following reasons: a high-riding transverse foramen of the C-2 vertebra present in 13 patients (left side in eight, right side in five), poor screw purchase in two (left side in both), screw malposition in one (left side), severe degenerative arthritis in one (right side), neurofibroma in one (right side), and fracture of the C-1 lateral mass in one (left side). Six weeks postsurgery, one patient presented with a broken screw and required occipitocervical fusion with a Steinmann pin and wire cable from the occiput to C-3 to achieve solid fusion. Solid fusions were achieved in the other 18 patients (mean follow-up period 31 months, range 14–54 months); there was no delayed screw breakage, wire breakage, or spinal instability. There were no operative or postoperative neurological or vascular complications. The authors' experience demonstrates that unilateral C1–2 facet screw fixation with interspinous bone graft wiring is an excellent alternative in the treatment of atlantoaxial instability when bilateral screw fixation is contraindicated.