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  • Author or Editor: Mark D. Van Poppel x
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Mark Van Poppel, James W. Wheless, Dave F. Clarke, Amy McGregor, Mark H. McManis, Freedom F. Perkins Jr., Katherine Van Poppel, Stephen Fulton and Frederick A. Boop

Object

Functional mapping is important for determining surgical candidacy and also in epilepsy surgery planning. However, in young children and uncooperative patients, language mapping has been particularly challenging despite the advances in performing noninvasive functional studies. In this study the authors review a series of children with epilepsy who underwent language mapping with magnetoencephalography (MEG) while sedated or sleeping, to determine receptive language localization for presurgical evaluation.

Methods

The authors undertook a retrospective review of patients who underwent MEG between December 2007 and July 2009, and identified 15 individuals who underwent passive language testing as part of their presurgical evaluation because they were unable to participate in traditional language testing, such as Wada or functional MRI. Factors necessitating passive language testing included age and neurocognitive development.

Results

Three of the 15 patients were deemed candidates for epilepsy surgery based on the results from standard preoperative testing, including video electroencephalography, MRI, and passive receptive language testing using MEG technology. The MEG studies were used successfully to localize language in all 3 patients, creating opportunities for seizure freedom through surgery that would not otherwise have been available. All 3 patients then underwent resective epilepsy surgery without experiencing postoperative language deficits.

Conclusions

This case series is the first to look at language mapping during sleep (passive language mapping) in which MEG was used and is the first to evaluate passive language testing in a patient population with intracranial pathological entities. This case series demonstrates that MEG can provide an alternative method for receptive language localization in patients with barriers to more traditional language testing, and in these 3 cases surgery was performed safely based on the results.

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Mark Van Poppel, Paul Klimo Jr., Mariko Dewire, Robert A. Sanford, Frederick Boop, Alberto Broniscer, Karen Wright and Amar J. Gajjar

Object

Brain tumors in infants are often large, high grade, and vascular, making complete resection difficult and placing children at risk for neurological complications and excessive blood loss. Neoadjuvant chemotherapy may reduce tumor vascularity and volume, which can facilitate resection. The authors evaluated how an ongoing institutional prospective chemotherapy trial would affect patients who did not have a gross-total resection (GTR) immediately and who therefore required further surgical intervention to achieve definitive tumor resection.

Methods

Thirteen infants (4 girls and 9 boys) who were enrolled in an institutional protocol in which they were treated with multiagent chemotherapy (methotrexate, vincristine, cisplatin, and cyclophosphamide with vinblastine for high-risk patients) subsequently underwent second-look surgery. The primary outcome was extent of resection achieved in postchemotherapy surgery. Secondary outcomes included intraoperative blood loss, radiographic response to the chemotherapy, complications during chemotherapy, and survival.

Results

Three infants underwent biopsy, 9 underwent subtotal resection, and 1 patient did not undergo surgery prior to chemotherapy. On subsequent second-look surgery, 11 of 13 patients had a GTR, 1 had a near-total resection, and 1 had a subtotal resection. In each case, a marked reduction in tumor vascularity was observed intraoperatively. The average blood loss was 19% of estimated blood volume, and 6 (46%) of 13 patients required a blood transfusion. Radiographically, chemotherapy induced a reduction in tumor volume in 9 (69%) of 13 patients. Emergency surgery was required in 2 patients during chemotherapy, 1 for intratumoral hemorrhage and 1 for worsening peritumoral edema. The average follow-up period for this cohort was 16.5 months, and at last follow-up, 4 patients (31%) had died, 1 patient had progressive metastatic spinal disease, and the rest had either no evidence of disease or stable disease.

Conclusions

A GTR of pediatric brain tumors is one of the most important predictors of outcome. The application of the authors' neoadjuvant induction chemotherapy protocol in a variety of tumor types resulted in devascularization of all tumors and volume regression in the majority, and subsequently facilitated resection, with acceptable intraoperative blood loss. Intracranial complications may occur during chemotherapy, ranging from incidental and asymptomatic to life threatening, necessitating close monitoring of these children.

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Paul Klimo Jr., Mark Van Poppel, Clinton J. Thompson, Lissa C. Baird, Ann-Christine Duhaime and Ann Marie Flannery

Object

The objective of this systematic review and meta-analysis was twofold: to answer the question “What is the evidence for the effectiveness of prophylactic intravenous antibiotics for infection prevention in shunt surgery?” and to make treatment recommendations based on the available evidence.

Methods

The US National Library of Medicine PubMed/MEDLINE database and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words relevant to prophylactic antibiotic use in children undergoing a shunt operation. Abstracts were reviewed to identify which studies met the inclusion criteria. An evidentiary table was assembled summarizing the studies and the quality of evidence (Classes I-III). A meta-analysis was conducted using a random-effects model to calculate a cumulative estimate of treatment effect using risk ratio (RR). Heterogeneity was assessed using chi-square and I2 statistics. A sensitivity analysis was also conducted. Based on the quality of the literature and the result of the meta-analysis, a recommendation was rendered (Level I, II, or III).

Results

Nine studies (4 Class I, 3 Class II, and 2 Class III) met our inclusion criteria. Of 7 randomized controlled trials (RCTs), 3 were downgraded from Class I to Class II because of significant quality issues, and all RCTs were potentially underpowered. In only 2 Class in retrospective cohort studies were preoperative antibiotic agents found to be protective against shunt infection. When data from the individual studies were pooled together, the infection rate in the prophylactic antibiotics group was 5.9% compared with 10.7% in the control group. Using a random-effects model, the cumulative RR was 0.55 (95% CI 0.38–0.81), indicating a protective benefit of prophylactic preoperative intravenous antibiotics. A sensitivity analysis of RCTs only (n = 7) also demonstrated a statistical benefit, but an analysis of higher-quality RCTs only (n = 4) did not.

Conclusions

Within the limits of this systematic review and meta-analysis, administration of preoperative antibiotic agents for shunt surgery in children was found to lower the infection risk (quality of evidence: Class II; strength of recommendation, Level II).

Recommendation

The use of preoperative antibiotic agents can be recommended to prevent shunt infection in patients with hydrocephalus. It was only by combining the results of the various underpowered studies (meta-analysis) that the use of preoperative antibiotics for shunt surgery in children was shown to lower the risk of shunt infection. Strength of Recommendation: Level II, moderate degree of clinical certainty.

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Jennifer M. Strahle, Rukayat Taiwo, Christine Averill, James Torner, Chevis N. Shannon, Christopher M. Bonfield, Gerald F. Tuite, Tammy Bethel-Anderson, Jerrel Rutlin, Douglas L. Brockmeyer, John C. Wellons III, Jeffrey R. Leonard, Francesco T. Mangano, James M. Johnston, Manish N. Shah, Bermans J. Iskandar, Elizabeth C. Tyler-Kabara, David J. Daniels, Eric M. Jackson, Gerald A. Grant, Daniel E. Couture, P. David Adelson, Tord D. Alden, Philipp R. Aldana, Richard C. E. Anderson, Nathan R. Selden, Lissa C. Baird, Karin Bierbrauer, Joshua J. Chern, William E. Whitehead, Richard G. Ellenbogen, Herbert E. Fuchs, Daniel J. Guillaume, Todd C. Hankinson, Mark R. Iantosca, W. Jerry Oakes, Robert F. Keating, Nickalus R. Khan, Michael S. Muhlbauer, J. Gordon McComb, Arnold H. Menezes, John Ragheb, Jodi L. Smith, Cormac O. Maher, Stephanie Greene, Michael Kelly, Brent R. O’Neill, Mark D. Krieger, Mandeep Tamber, Susan R. Durham, Greg Olavarria, Scellig S. D. Stone, Bruce A. Kaufman, Gregory G. Heuer, David F. Bauer, Gregory Albert, Jeffrey P. Greenfield, Scott D. Wait, Mark D. Van Poppel, Ramin Eskandari, Timothy Mapstone, Joshua S. Shimony, Ralph G. Dacey Jr., Matthew D. Smyth, Tae Sung Park and David D. Limbrick Jr.

OBJECTIVE

Scoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors’ goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis.

METHODS

A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°).

RESULTS

Based on available imaging of patients with CM-I and syrinx, 260 of 825 patients (31%) had a clear diagnosis of scoliosis based on radiographs or coronal MRI. Forty-nine patients (5.9%) did not have scoliosis, and in 516 (63%) patients, a clear determination of the presence or absence of scoliosis could not be made. Comparison of patients with and those without a definite scoliosis diagnosis indicated that scoliosis was associated with wider syrinxes (8.7 vs 6.3 mm, OR 1.25, p < 0.001), longer syrinxes (10.3 vs 6.2 levels, OR 1.18, p < 0.001), syrinxes with their rostral extent located in the cervical spine (94% vs 80%, OR 3.91, p = 0.001), and holocord syrinxes (50% vs 16%, OR 5.61, p < 0.001). Multivariable regression analysis revealed syrinx length and the presence of holocord syrinx to be independent predictors of scoliosis in this patient cohort. Scoliosis was not associated with sex, age at CM-I diagnosis, tonsil position, pB–C2 distance (measured perpendicular distance from the ventral dura to a line drawn from the basion to the posterior-inferior aspect of C2), clivoaxial angle, or frontal-occipital horn ratio. Average curve magnitude was 29.9°, and 37.7% of patients had a left thoracic curve. Older age at CM-I or syrinx diagnosis (p < 0.0001) was associated with greater curve magnitude whereas there was no association between syrinx dimensions and curve magnitude.

CONCLUSIONS

Syrinx characteristics, but not tonsil position, were related to the presence of scoliosis in patients with CM-I, and there was an independent association of syrinx length and holocord syrinx with scoliosis. Further study is needed to evaluate the nature of the relationship between syrinx and scoliosis in patients with CM-I.