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Michael Garcia, Christopher Daugherty, Bertha Ben Khallouq and Todd Maugans

OBJECTIVE

The Internet is used frequently by patients and family members to acquire information about pediatric neurosurgical conditions. The sources, nature, accuracy, and usefulness of this information have not been examined recently. The authors analyzed the results from searches of 10 common pediatric neurosurgical terms using a novel scoring test to assess the value of the educational information obtained.

METHODS

Google and Bing searches were performed for 10 common pediatric neurosurgical topics (concussion, craniosynostosis, hydrocephalus, pediatric brain tumor, pediatric Chiari malformation, pediatric epilepsy surgery, pediatric neurosurgery, plagiocephaly, spina bifida, and tethered spinal cord). The first 10 “hits” obtained with each search engine were analyzed using the Currency, Relevance, Authority, Accuracy, and Purpose (CRAAP) test, which assigns a numerical score in each of 5 domains. Agreement between results was assessed for 1) concurrent searches with Google and Bing; 2) Google searches over time (6 months apart); 3) Google searches using mobile and PC platforms concurrently; and 4) searches using privacy settings. Readability was assessed with an online analytical tool.

RESULTS

Google and Bing searches yielded information with similar CRAAP scores (mean 72% and 75%, respectively), but with frequently differing results (58% concordance/matching results). There was a high level of agreement (72% concordance) over time for Google searches and also between searches using general and privacy settings (92% concordance). Government sources scored the best in both CRAAP score and readability. Hospitals and universities were the most prevalent sources, but these sources had the lowest CRAAP scores, due in part to an abundance of self-marketing. The CRAAP scores for mobile and desktop platforms did not differ significantly (p = 0.49).

CONCLUSIONS

Google and Bing searches yielded useful educational information, using either mobile or PC platforms. Most information was relevant and accurate; however, the depth and breadth of information was variable. Search results over a 6-month period were moderately stable. Pediatric neurosurgery practices and neurosurgical professional organization websites were inferior (less current, less accurate, less authoritative, and less purposeful) to governmental and encyclopedia-type resources such as Wikipedia. This presents an opportunity for pediatric neurosurgeons to participate in the creation of better online patient/parent educational material.

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Pankaj K. Agarwalla, Christopher J. Stapleton, Michael T. Phillips, Brian P. Walcott, Andrew S. Venteicher and Christopher S. Ogilvy

Object

Moyamoya disease/syndrome (MMD/S) is a progressive, occlusive vasculopathy of the intracranial vasculature that leads to ischemic and hemorrhagic strokes. Significant debate exists regarding the role of indirect cerebrovascular bypass surgery in its management. The authors review their institution's experience with indirect bypass in the surgical management of patients with MMD/S.

Methods

The authors conducted a retrospective review of patients with MMD/S who underwent encephaloduroarteriosynangiosis (EDAS), a form of indirect bypass, from 1996 to 2013.

Results

A total of 37 patients (52 hemispheres) underwent an EDAS procedure for MMD/S; 21 patients received revascularization of both hemispheres. Patients presented with the following: 49% with stroke, 35% with transient ischemic attack, 13% with hemorrhage, and 3% with seizure. The mean Suzuki grade was 3.46. The number of patients with a modified Rankin Scale score of 0–1 improved from 21 to 29 (p = 0.002) from the time of surgery to the time of last follow-up. The number of neurological events (i.e., transient ischemic attacks, strokes, and hemorrhages) decreased from a mean of 1.7 events per patient to 0.14 (p < 0.001). The mean length of follow-up was 32.8 months.

Conclusions

This series demonstrates that EDAS is an effective procedure for MMD/S in a North American cohort of patients.

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Thomas J. Buell, Davis G. Taylor, Ching-Jen Chen, Christopher I. Shaffrey, Justin S. Smith and Shay Bess

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Darryl Lau, Cecilia L. Dalle Ore, Patrick Reid, Michael M. Safaee, Vedat Deviren, Justin S. Smith, Christopher I. Shaffrey and Christopher P. Ames

OBJECTIVE

The benefits and utility of routine neuromonitoring with motor and somatosensory evoked potentials during lumbar spine surgery remain unclear. This study assesses measures of performance and utility of transcranial motor evoked potentials (MEPs) during lumbar pedicle subtraction osteotomy (PSO).

METHODS

This is a retrospective study of a single-surgeon cohort of consecutive adult spinal deformity (ASD) patients who underwent lumbar PSO from 2006 to 2016. A blinded neurophysiologist reviewed individual cases for MEP changes. Multivariate analysis was performed to determine whether changes correlated with neurological deficits. Measures of performance were calculated.

RESULTS

A total of 242 lumbar PSO cases were included. MEP changes occurred in 38 (15.7%) cases; the changes were transient in 21 cases (55.3%) and permanent in 17 (44.7%). Of the patients with permanent changes, 9 (52.9%) had no recovery and 8 (47.1%) had partial recovery of MEP signals. Changes occurred at a mean time of 8.8 minutes following PSO closure (range: during closure to 55 minutes after closure). The mean percentage of MEP signal loss was 72.9%. The overall complication rate was 25.2%, and the incidence of new neurological deficits was 4.1%. On multivariate analysis, MEP signal loss of at least 50% was not associated with complication (p = 0.495) or able to predict postoperative neurological deficits (p = 0.429). Of the 38 cases in which MEP changes were observed, the observation represented a true-positive finding in only 3 cases. Postoperative neurological deficits without MEP changes occurred in 7 cases. Calculated measures of performance were as follows: sensitivity 30.0%, specificity 84.9%, positive predictive value 7.9%, and negative predictive value 96.6%. Regarding the specific characteristics of the MEP changes, only a signal loss of 80% or greater was significantly associated with a higher rate of neurological deficit (23.0% vs 0.0% for loss of less than 80%, p = 0.021); changes of less than 80% were not associated with postoperative deficits.

CONCLUSIONS

Neuromonitoring has a low positive predictive value and low sensitivity for detecting new neurological deficits. Even when neuromonitoring is unchanged, patients can still have new neurological deficits. The utility of transcranial MEP monitoring for lumbar PSO remains unclear but there may be advantages to its use.

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Michael M. Safaee, Cecilia L. Dalle Ore, Corinna C. Zygourakis, Vedat Deviren and Christopher P. Ames

OBJECTIVE

Proximal junctional kyphosis (PJK) is a well-recognized complication of surgery for adult spinal deformity and is characterized by increased kyphosis at the upper instrumented vertebra (UIV). PJK prevention strategies have the potential to decrease morbidity and cost by reducing rates of proximal junctional failure (PJF), which the authors define as radiographic PJK plus clinical sequelae requiring revision surgery.

METHODS

The authors performed an analysis of 195 consecutive patients with adult spinal deformity. Age, sex, levels fused, upper instrumented vertebra (UIV), use of 3-column osteotomy, pelvic fixation, and mean time to follow-up were collected. The authors also reviewed operative reports to assess for the use of surgical adjuncts targeted toward PJK prevention, including ligament augmentation, hook fixation, and vertebroplasty. The cost of surgery, including direct and total costs, was also assessed at index surgery and revision surgery. Only revision surgery for PJF was included.

RESULTS

The mean age of the cohort was 64 years (range 25–84 years); 135 (69%) patients were female. The mean number of levels fused was 10 (range 2–18) with the UIV as follows: 2 cervical (1%), 73 upper thoracic (37%), 108 lower thoracic (55%), and 12 lumbar (6%). Ligament augmentation was used in 99 cases (51%), hook fixation in 60 cases (31%), and vertebroplasty in 71 cases (36%). PJF occurred in 18 cases (9%). Univariate analysis found that ligament augmentation and hook fixation were associated with decreased rates of PJF. However, in a multivariate model that also incorporated age, sex, and UIV, only ligament augmentation maintained a significant association with PJF reduction (OR 0.196, 95% CI 0.050–0.774; p = 0.020). Patients with ligament augmentation, compared with those without, had a higher cost of index surgery, but ligament augmentation was overall cost effective and produced significant cost savings. In sensitivity analyses in which we independently varied the reduction in PJF, cost of ligament augmentation, and cost of reoperation by ± 50%, ligament augmentation remained a cost-effective strategy for PJF prevention.

CONCLUSIONS

Prevention strategies for PJK/PJF are limited, and their cost-effectiveness has yet to be established. The authors present the results of 195 patients with adult spinal deformity and show that ligament augmentation is associated with significant reductions in PJF in both univariate and multivariate analyses, and that this intervention is cost-effective. Future studies will need to determine if these clinical results are reproducible, but for high-risk cases, these data suggest an important role of ligament augmentation for PJF prevention and cost savings.

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Michael J. Rauzzino, Christopher I. Shaffrey, James Wagner, Russ Nockels and Mark Abel

The indications for surgical intervention in patients with idiopathic scoliosis have been well defined. The goals of surgery are to achieve fusion and arrest progressive curvature while restoring normal coronal and sagittal balance. As first introduced by Harrington, posterior fusion, the gold standard of treatment, has a proven record of success. More recently, anterior techniques for performing fusion procedures via either a thoracotomy or a retroperitoneal approach have been popularized in attempts to achieve better correction of curvature, preserve motion segments, and avoid some of the complications of posterior fusion such as the development of the flat-back syndrome. Anterior instrumentation alone, although effective, can be kyphogenic and has been shown to be associated with complications such as pseudarthrosis and instrumentation failure. Performing a combined approach in patients with scoliosis and other deformities has become an increasingly popular procedure to achieve superior correction of deformity and to minimize later complications. Indications for a combined approach (usually consisting of anterior release, arthrodesis with or without use of instrumentation, and posterior segmental fusion) include: prevention of crankshaft phenomenon in juvenile or skeletally immature adolescents; correction of large curves (75°) or excessively rigid curves in skeletally mature or immature patients; correction of curves with large sagittal-plane deformities such as thoracic kyphosis (> 90°) or thoracic lordosis (> 20°); and correction of thoracolumbar curves that need to be fused to the sacrum. Surgery may be performed either in a staged proceedure or, more commonly, in a single sitting. The authors discuss techniques for combined surgery and complication avoidance.

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Christopher S. Eddleman, Michael C. Hurley, Bernard R. Bendok and H. Hunt Batjer

Most cavernous carotid aneurysms (CCAs) are considered benign lesions, most often asymptomatic, and to have a natural history with a low risk of life-threatening complications. However, several conditions may exist in which treatment of these aneurysms should be considered. Several options are currently available regarding the management of CCAs with resultant good outcomes, namely expectant management, luminal preservation strategies with or without addressing the aneurysm directly, and Hunterian strategies with or without revascularization procedures. In this article, we discuss the sometimes difficult decision regarding whether to treat CCAs. We consider the natural history of several types of CCAs, the clinical presentation, the current modalities of CCA management and their outcomes to aid in the management of this heterogeneous group of cerebral aneurysms.

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William B. Feldman, Aaron J. Clark, Michael Safaee, Christopher P. Ames and Andrew T. Parsa

Object

Myxopapillary ependymomas (MPEs) are rare WHO Grade I tumors found in the conus medullaris, cauda equina, and filum terminale. Treatment generally consists of resection with or without adjuvant radiotherapy. Evidence-based guidelines for surgical management are lacking due to the rarity of this tumor.

Methods

An English-language PubMed search was performed using the key words “myxopapillary” and “ependymoma.” Reports describing fewer than 3 patients or those lacking data on the extent of resection or radiotherapy were excluded. A total of 28 articles describing 475 patients met the authors' inclusion criteria. Patients were grouped by extent of resection and whether or not they underwent adjuvant radiotherapy. Differences in recurrence rates were assessed by chi-square test.

Results

The overall recurrence rate was 15.5% in patients treated by gross-total resection (GTR) and 32.6% in patients treated by subtotal resection (STR), irrespective of whether they underwent adjuvant therapy (p < 0.001). Regardless of the extent of resection, adjuvant radiotherapy was not associated with a decrease in recurrence rates. The overall recurrence rate was 15.6% in patients who underwent GTR and radiotherapy compared with 15.9% in patients who underwent GTR alone (p = 0.58), and it was 29.3% in patients who underwent STR and radiotherapy compared with 35.1% in those who underwent STR alone (p = 0.53). The difference between recurrence rates for patients who underwent GTR alone versus STR and radiotherapy was statistically significant (p = 0.02). Subgroup analysis demonstrated significantly higher recurrence rates in pediatric patients compared with adults (40.5% vs 23.4%, respectively; p = 0.02). Even in the setting of GTR alone, recurrence rates were higher in pediatric patients (65% vs 7.6%; p < 0.001).

Conclusions

Gross-total resection alone is associated with decreased recurrence rates compared with STR with or without radiotherapy. The authors' results suggest that treatment goals should include attempted GTR whenever possible. The observation that children benefitted from radiation therapy to a greater extent than did adults suggests that biological differences between tumors in these patient populations warrants more rigorous scientific studies.

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Gregory D. Schroeder, Nik Hjelm, Alexander R. Vaccaro, Michael S. Weinstein and Christopher K. Kepler

OBJECTIVE

The aim of this paper was to compare the severity of the initial neurological injury as well as the early changes in the American Spinal Injury Association (ASIA) motor score (AMS) between central cord syndrome (CCS) patients with and without an increased T2 signal intensity in their spinal cord.

METHODS

Patients with CCS were identified and stratified based on the presence of increased T2 signal intensity in their spinal cord. The severity of the initial neurological injury and the progression of the neurological injury over the 1st week were measured according to the patient's AMS. The effect of age, sex, congenital stenosis, surgery within 24 hours, and surgery in the initial hospitalization on the change in AMS was determined using an analysis of variance.

RESULTS

Patients with increased signal intensity had a more severe initial neurological injury (AMS 57.6 vs 75.3, respectively, p = 0.01). However, the change in AMS over the 1st week was less severe in patients with an increase in T2 signal intensity (−0.85 vs −4.3, p = 0.07). Analysis of variance did not find that age, sex, Injury Severity Score, congenital stenosis, surgery within 24 hours, or surgery during the initial hospitalization affected the change in AMS.

CONCLUSIONS

The neurological injury is different between patients with and without an increased T2 signal intensity. Patients with an increased T2 signal intensity are likely to have a more severe initial neurological deficit but will have relatively minimal early neurological deterioration. Comparatively, patients without an increase in the T2 signal intensity will likely have a less severe initial injury but can expect to have a slight decline in neurological function in the 1st week.

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Cecilia L. Dalle Ore, Darryl Lau, Jessica L. Davis, Michael M. Safaee and Christopher P. Ames

Juvenile ossifying fibroma (JOF) is a rare benign bone tumor that occurs most frequently in the craniofacial bones of children and young adults. There are few case reports that describe its involvement outside the craniofacial skeleton, especially within the spinal column. While JOF is classified as a benign lesion, it may be locally aggressive and demonstrate a high propensity for recurrence, even after resection. Definitive surgical management may be challenging in naive cases, but it is particularly challenging in recurrent cases and when extensive spinal reconstruction is warranted. In this report, the authors describe the diagnosis and surgical management of a 29-year-old man who presented with a large recurrent sacral trabecular-subtype JOF. A review of literature regarding JOFs, management of recurrent primary spinal tumors, and sacral reconstruction are discussed.