Faculty Bibliography

The authors report a case of a nonachondroplastic dwarf with severe basilar invagination and compression of the cervicomedullary junction (CMJ) due to juvenile rheumatoid arthritis. Initially excellent reduction of the invagination and decompression of the CMJ was achieved using posterior fixation. However, 1 month postoperatively symptoms recurred and the authors found imaging evidence of recurrence as well. The patient subsequently underwent an endoscopic transnasal resection of the dens with assistance of Iso-C navigation. He recovered well and tolerated regular diet on postoperative Day 2.

Chiari malformations may present with a wide range of symptoms and signs. Nevertheless, focal foot weakness as a presentation of a Chiari malformation has not been described in the pediatric neurosurgical literature. Two children with Chiari malformations and holocord syringomyelia presented with manifestations of a supposed isolated lumbar radiculopathy. Neurological deficits completely resolved after decompressive suboccipital craniectomy and cervical laminectomy. These cases emphasize the importance of imaging the entire craniospinal axis and avoidance of therapeutic intervention specifically aimed at a radiculopathic process when initial imaging fails to show a structural abnormality at the spinal level of deficit. The possible pathophysiological origins for this unusual presentation are discussed. Based on the experience gained with these patients, recommendations are made regarding the diagnostic workup and management of this entity in children presenting with focal deficits that are not supported by imaging of the affected root levels. Chiari malformations may rarely masquerade as lower motor and sensory deficits, and appropriate treatment may result in excellent recovery of function.

OBJECT: In this retrospective analysis the authors describe the assessment and outcomes of 90 patients who underwent placement of posterior instrumentation at the cervicothoracic junction following the resection of a primary or metastatic tumor during a 10-year period. METHODS: All patients underwent a posterolateral laminectomy including uni- or bilateral facetectomy, and 44 patients additionally required vertebral body resection and reconstruction. In patients who underwent C-6 or C-7 decompression, the posterior instrumentation strategies changed from the use of lateral mass plate systems (LMPSs) to lateral mass screw/rod systems (LMSRSs). Similarly, for T1-3 tumor decompression, the strategy shifted from sublaminar hook/rod systems (SHRSs) to the use of pedicle screw systems (PSSs) in which the surgeon used either a 6.25-mm rod or dual-diameter rods with or without a connector. RESULTS: The overall surgical complication rate was 19% including fixation failure in 11 patients (12%), 6 of whom required reoperation. Fixation failure rates for cervical decompression decreased from 2 (29%) of 7 patients in the LMPS group to 0 (0%) of 8 in the LMSRS group (p = 0.2). The fixation failure rates for thoracic decompression were 7 (15%) of 48 patients in the SHRS group, and there was a decrease to 2 (7%) of 27 in the PSS group (p = 0.48). Neurological and functional outcomes including American Spinal Injury Association, Eastern Cooperative Oncology Group, and Medical Research Council muscle strength and pain scores remained stable or improved in 94, 96, 100, and 96% of patients, respectively. CONCLUSIONS: Current posterior instrumentation strategies involving LMSRSs and PSSs provide excellent and safe stabilization of the cervicothoracic junction following resection of primary or metastatic tumors

OBJECT/OBJECTIVE:The extended transsphenoidal approach is a less invasive method for removing purely suprasellar lesions compared with traditional transcranial approaches. Most advocates have used a sublabial incision and a microscope and have reported a significant risk of cerebrospinal fluid (CSF) leakage. The authors report on a series of purely endoscopic endonasal surgeries for resection of suprasellar supradiaphragmatic lesions above a normal-sized sella turcica with a low risk of CSF leakage. METHODS:A purely endoscopic endonasal approach was used to remove suprasellar lesions in a series of 10 patients. Five lesions were prechiasmal (three tuberculum sellae and two planum sphenoidale meningiomas) and five were post-chiasmal (four craniopharyngiomas and one Rathke cleft cyst). The floor of the planum sphenoidale and the sella turcica was reconstructed using a multilayer closure with autologous and synthetic materials. Spinal drainage was performed in only five cases. Complete resection of the lesions was achieved in all but one patient. The pituitary stalk was preserved in all but one patient, whose stalk was invaded by a craniopharyngioma and who had preoperative diabetes insipidus (DI). Vision improved postoperatively in all patients with preoperative impairment. Six patients had temporary DI; in five, the DI became permanent. Four patients with craniopharyngiomas required cortisone and thyroid replacement. After a mean follow up of 10 months, there was only one transient CSF leak when a lumbar drain was clamped prematurely on postoperative Day 5. CONCLUSIONS:A purely endoscopic endonasal approach to suprasellar supradiaphragmatic lesions is a feasible minimally invasive alternative to craniotomy. With a multilayer closure, the risk of CSF leakage is low and lumbar drainage can be avoided. A larger series will be required to validate this approach.

BACKGROUND CONTEXT/BACKGROUND:Paragangliomas are neuroendocrine tumors that most frequently arise in the adrenal medulla, carotid body, and glomus jugulare. However, they have been reported in many other sites throughout the body. Within the central nervous system, the overwhelming majority of paragangliomas arise intradurally in the area of the cauda equina. We report a case of a woman who presented with back pain and radiculopathy and was found to have an intraosseous sacral mass on magnetic resonance imaging (MRI). Operative biopsy revealed that this lesion was a paraganglioma. Chest, abdomen, and pelvis computed tomography scans revealed no other tumors. This lesion was treated with limited resection, decompression, stabilization, and radiation therapy. PURPOSE/OBJECTIVE:To report a rare case of an intrasacral paraganglioma that presented with back pain and radiculopathy and was treated with intralesional decompression, stabilization, and radiation. STUDY DESIGN/METHODS:Observational case report. METHODS:A 69-year-old woman presented with back and leg pain. An MRI scan revealed a grade II spondylolisthesis at L5/S1 and a left-sided intraosseus mass at S1 with significant obstruction of the left S1 nerve root foramen. The patient underwent initially an open biopsy of this lesion that revealed a paraganglioma. Subsequently, she underwent transarterial embolization of this lesion, partial resection with decompression of the nerve root, and stabilization and arthrodesis from L4 to the ilium. RESULTS:Intraoperatively, a highly vascular lesion was encountered. The patient's back and leg pain improved significantly after surgery. She was referred for intensity-modulated radiation therapy. One year after surgery, she was neurologically intact without evidence of growth of the lesion. CONCLUSIONS:Only two cases of primary intraosseous sacral paragangliomas were reported in the past. We believe that paragangliomas should be included in the differential diagnosis of intraosseous sacral tumors. Optimal treatment of the lesions can be difficult because of their hypervascular nature and the high morbidity associated with complete surgical resection. Treatment should combine preoperative embolisation, surgical resection if possible, and radiation therapy.

OBJECTIVE:Oxidative damage has been implicated in the pathogenesis of cerebral ischemia. We previously demonstrated that exogenously supplied dehydroascorbic acid (DHA), an oxidized, blood-brain barrier transportable form of the antioxidant ascorbic acid (AA), improves outcome after experimental stroke. METHODS:To investigate the neuroprotective effect of DHA therapy, we measured cerebral AA levels using a novel assay, quantified markers of lipid peroxidation, and evaluated infarct volume after reperfused stroke in a murine model. All experiments were performed using a new citrate/sorbitol-stabilized DHA formulation to improve the stability of the compound. RESULTS:Intraparenchymal AA levels declined after cerebral ischemia/reperfusion and were repleted in a dose-dependent fashion by postischemic administration of intravenous DHA (P < 0.01). Repletion of these levels was associated with reductions in cerebral malondialdehyde levels (P < 0.05), which were also elevated after reperfused stroke. DHA repletion of interstitial AA levels and reduction in cerebral lipid peroxidation was associated with dose-dependent reductions in infarct volume (P < 0.05). CONCLUSION/CONCLUSIONS:Together, these results indicate that an intravenous cerebroprotective dose of citrate/sorbitol-stabilized DHA is correlated with increased brain ascorbate levels and a suppression of excessive oxidative metabolism.

The complement cascade has been implicated in ischemia/reperfusion injury, and recent studies have shown that complement inhibition is a promising treatment option for acute stroke. The development of clinically useful therapies has been hindered, however, by insufficient understanding of which complement subcomponents contribute to post-ischemic injury. To address this issue, we subjected mice deficient in selected complement proteins (C1q, C3, C5) to transient focal cerebral ischemia. Of the strains investigated, only C3-/- mice were protected, as demonstrated by 34% reductions in both infarct volume (P<0.01) and neurological deficit score (P<0.05). C3-deficient mice also manifested decreased granulocyte infiltration (P<0.02) and reduced oxidative stress (P<0.05). Finally, administration of a C3a-receptor antagonist resulted in commensurate neurological improvement and stroke volume reduction (P<0.05). Together, these results establish C3 activation as the key constituent in complement-related inflammatory tissue injury following stroke and suggest a C3a anaphylatoxin-mediated mechanism.

OBJECTIVE AND IMPORTANCE/OBJECTIVE:This case summarizes our experience with the first described intradural extramedullary cavernous malformation at the foramen magnum and reminds the neurosurgical community to consider cavernous malformations in the differential diagnosis for subarachnoid hemorrhage. CLINICAL PRESENTATION/METHODS:A 21-year-old man presented with an occipital headache, photophobia, nausea, neck stiffness, and fever of 10 days' duration. A lumbar puncture yielded a clear pink fluid with 300 leukocytes/mm3 (30% neutrophils and 65% lymphocytes) and 42,200 erythrocytes/mm3, a protein count of 243 mg/dl, and a glucose count of 56 mg/dl. Computed tomography revealed a 1.5-cm right-sided dural-based mass of high attenuation that spanned the foramen magnum and a segment of the upper spinal canal. Magnetic resonance imaging showed a loculated, heterogeneously enhancing mass with a cystic component that slightly displaced the medulla to the left. An angiogram was negative for aneurysms and vascular malformations but did show an area of early filling and slow washout of the epidural venous plexus at the posterior canal margin of C1 and C2. INTERVENTION/METHODS:A suboccipital craniectomy and C1 laminectomy were performed. Upon opening of the dura, an encapsulated mass was visualized. The lesion was located on the right lateral surface of the cervicomedullary junction and was entirely extraparenchymal. The mass was microsurgically dissected, and its associated venous malformation was left intact. The patient's postoperative course was uneventful, with a return to baseline function. Pathological examination confirmed the diagnosis of cavernous malformation. CONCLUSION/CONCLUSIONS:Our report not only presents a unique combination of pathological lesion, location, and presentation but also demonstrates that such lesions may be treated surgically with excellent results.

OBJECT/OBJECTIVE:Proinflammatory adhesion molecule expression has been demonstrated to be elevated in patients with aneurysmal subarachnoid hemorrhage (SAH). Recent studies have shown that elevations in soluble intercellular adhesion molecule-1 (ICAM-1) may be predictive of poor outcome in patients with good grade (Hunt and Hess Grades 1-2) aneurysmal SAH at delayed time points that correspond with the risk period for cerebral vasospasm. In addition, ICAM-1 is upregulated in experimental models of vasospasm. Unfortunately, the relationship of adhesion molecule expression to human vasospasm remains unclear. The authors hypothesized that the delayed elevation of soluble ICAM-1 in patients with aneurysmal SAH is associated with the development of cerebral vasospasm. METHODS:Eighty-nine patients with aneurysmal SAH were prospectively enrolled in a study and stratified according to the presence or absence of vasospasm, as evidenced by daily monitoring of transcranial Doppler (TCD) velocities (presence, > 200 cm/second; absence, < 120 cm/second). Levels of soluble ICAM-1 were determined using enzyme-linked immunosorbent assay every other day for 12 days post-SAH. An analysis of covariance model was used to evaluate trends in soluble ICAM-1 levels from 2 days prior to 6 days after the occurrence of documented vasospasm. Two groups of patients, matched for admission admission Hunt and Hess grade, were compared: nine patients with TCD velocities greater than 200 cm/second and nine patients with TCD velocities less than 120 cm/second. From among the patients with TCD velocities greater than 200 cm/second six patients with angiographically documented vasospasm were selected. Patients with TCD velocities less than 120 cm/second and matched admission Hunt and Hess grades but without angiographically documented vasospasm were selected. Patients with TCD-demonstrated vasospasm showed a significant mean rate of rise (p < 0.01) in soluble ICAM-1 levels during the perivasospasm period, but admission Hunt and Hess grade-matched control patients did not (p = not significant [NS]). There was a significant difference between these groups' rates of soluble ICAM increase (p < 0.01). Patients with both TCD- and angiographically demonstrated vasospasm likewise showed a highly significant mean rate of increase in soluble ICAM-1 levels during the perivasospasm period (p < 0.01), whereas admission Hunt and Hess grade-matched controls did not (p = NS). The difference beween these groups' rates of increase was highly significant (p < 0.001). CONCLUSIONS:These data suggest a role for ICAM-1 in the pathophysiology of cerebral vasospasm or its ischemic sequelae. As this relationship is further elucidated, adhesion molecules such as ICAM-1 may provide novel therapeutic targets in the prevention of vasospasm or its ischemic consequences.

OBJECTIVE:Recent data suggest that the increased expression of intercellular adhesion molecule-1 (ICAM-1) in atherosclerotic plaque taken from the carotid bifurcation correlates with the development of neurological symptoms. As a result, the authors sought to compare the serum levels of soluble forms of ICAM-1 (sICAM-1) in patients who were asymptomatic with those who were symptomatic for carotid artery stenosis as well as in patients who were matched in terms of sex, age, and risk factors who did not have carotid artery disease. METHODS:Using enzyme-linked immunosorbent assay, serum sICAM-1 levels were prospectively determined in 54 patients scheduled to undergo carotid endarterectomy for either symptomatic or asymptomatic high-grade stenosis (> or =60%) and in 5 additional patient controls. Data are expressed as mean +/- standard error of the mean, with significance defined as P < 0.05 using the Mann-Whitney two-tailed test for two-column comparison or analysis of variance and Fisher protected least significant difference test. RESULTS:Using a univariate model, serum sICAM-1 levels were significantly elevated in patients with carotid artery stenosis as compared with control patients without stenosis (347 +/- 15 ng/ml versus 216 +/- 8.2 ng/ml) (P < 0.01). When the asymptomatic and symptomatic patients with carotid artery stenosis were considered separately, these levels were still elevated relative to those of control patients (asymptomatic [312 +/- 18 ng/ml] and symptomatic [376 +/- 22 ng/ml] patients; P = 0.06 for asymptomatic versus control patients, P < 0.01 for symptomatic versus control patients). Symptomatic patients also had significantly elevated sICAM-1 levels as compared with asymptomatic patients (P < 0.05). Despite the fact that female patients demonstrated higher ICAM-1 levels than male patients (P < 0.05), sex, age, and risk factors such as the presence of hypercholesterolemia, diabetes, hypertension, or a history of smoking did not confound these findings. CONCLUSION/CONCLUSIONS:Levels of sICAM-1 are higher in patients with carotid stenosis than in control patients. Symptomatic patients demonstrate significantly elevated levels as compared with asymptomatic patients. These data support the contention that ICAM-1 is a reliable marker of carotid disease progression and suggest that serum levels may be useful in following certain asymptomatic patients.