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Benign Cysts of the Brain

An Analysis with Comparison of Results of Operative and Non-Operative Treatment in Thirty Cases

John H. Drew and Francis C. Grant

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Jeffrey P. Blount, Amber S. Gordon, Paul M. Foreman, and John H. Grant

The authors report on an infant with a bifrontal encephalocele that was associated with multisuture craniosynostosis, spasticity, and a progressively severe epilepsy. They describe the initial presentation, genetic screening results, staged multidisciplinary operative plans, clinical course, complications, and long-term surgical and developmental follow-up. To their knowledge, the comprehensive surgical management of this type of complicated congenital cranial anomaly has not been previously described.

Surgical management was staged and multidisciplinary and required careful attention to all 3 components of the condition: 1) hydrocephalus, 2) frontal meningoencephalocele, and 3) epilepsy.

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Kai J. Miller, Casey H. Halpern, Mark F. Sedrak, John A. Duncan III, and Gerald A. Grant

OBJECTIVE

Stereotactic laser ablation and neurostimulator placement represent an evolution in staged surgical intervention for epilepsy. As this practice evolves, optimal targeting will require standardized outcome measures that compare electrode lead or laser source with postprocedural changes in seizure frequency. The authors propose and present a novel stereotactic coordinate system based on mesial temporal anatomical landmarks to facilitate the planning and delineation of outcomes based on extent of ablation or region of stimulation within mesial temporal structures.

METHODS

The body of the hippocampus contains a natural axis, approximated by the interface of cornu ammonis area 4 and the dentate gyrus. The uncal recess of the lateral ventricle acts as a landmark to characterize the anterior-posterior extent of this axis. Several volumetric rotations are quantified for alignment with the mesial temporal coordinate system. First, the brain volume is rotated to align with standard anterior commissure–posterior commissure (AC-PC) space. Then, it is rotated through the axial and sagittal angles that the hippocampal axis makes with the AC-PC line.

RESULTS

Using this coordinate system, customized MATLAB software was developed to allow for intuitive standardization of targeting and interpretation. The angle between the AC-PC line and the hippocampal axis was found to be approximately 20°–30° when viewed sagittally and approximately 5°–10° when viewed axially. Implanted electrodes can then be identified from CT in this space, and laser tip position and burn geometry can be calculated based on the intraoperative and postoperative MRI.

CONCLUSIONS

With the advent of stereotactic surgery for mesial temporal targets, a mesial temporal stereotactic system is introduced that may facilitate operative planning, improve surgical outcomes, and standardize outcome assessment.

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Ehsan H. Balagamwala, Lilyana Angelov, Shlomo A. Koyfman, John H. Suh, Chandana A. Reddy, Toufik Djemil, Grant K. Hunter, Ping Xia, and Samuel T. Chao

Object

Stereotactic body radiotherapy (SBRT) has emerged as an important treatment option for spinal metastases from renal cell carcinoma (RCC) as a means to overcome RCC's inherent radioresistance. The authors reviewed the outcomes of SBRT for the treatment of RCC metastases to the spine at their institution, and they identified factors associated with treatment failure.

Methods

Fifty-seven patients (88 treatment sites) with RCC metastases to the spine received single-fraction SBRT. Pain relief was based on the Brief Pain Inventory and was adjusted for narcotic use according to the Radiation Therapy Oncology Group protocol 0631. Toxicity was scored according to Common Toxicity Criteria for Adverse Events version 4.0. Radiographic failure was defined as infield or adjacent (within 1 vertebral body [VB]) failure on follow-up MRI. Multivariate analyses were performed to correlate outcomes with the following variables: epidural, paraspinal, single-level, or multilevel disease (2–5 sites); neural foramen involvement; and VB fracture prior to SBRT. Kaplan-Meier analysis and Cox proportional hazards modeling were used for statistical analysis.

Results

The median follow-up and survival periods were 5.4 months (range 0.3–38 months) and 8.3 months (range 1.5–38 months), respectively. The median time to radiographic failure and unadjusted pain progression were 26.5 and 26.0 months, respectively. The median time to pain relief (from date of simulation) and duration of pain relief (from date of treatment) were 0.9 months (range 0.1–4.4 months) and 5.4 months (range 0.1–37.4 months), respectively. Multivariate analyses demonstrated that multilevel disease (hazard ratio [HR] 3.5, p = 0.02) and neural foramen involvement (HR 3.4, p = 0.02) were correlated with radiographic failure; multilevel disease (HR 2.3, p = 0.056) and VB fracture (HR 2.4, p = 0.046) were correlated with unadjusted pain progression. One patient experienced Grade 3 nausea and vomiting; no other Grade 3 or 4 toxicities were observed. Twelve treatment sites (14%) were complicated by subsequent vertebral fractures.

Conclusions

Stereotactic body radiotherapy for RCC metastases to the spine offers fast and durable pain relief with minimal toxicity. Stereotactic body radiotherapy seems optimal for patients who have solitary or few spinal metastases. Patients with neural foramen involvement are at an increased risk for failure.

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Jennifer L. Quon, Michelle Han, Lily H. Kim, Mary Ellen Koran, Leo C. Chen, Edward H. Lee, Jason Wright, Vijay Ramaswamy, Robert M. Lober, Michael D. Taylor, Gerald A. Grant, Samuel H. Cheshier, John R. W. Kestle, Michael S. B. Edwards, and Kristen W. Yeom

OBJECTIVE

Imaging evaluation of the cerebral ventricles is important for clinical decision-making in pediatric hydrocephalus. Although quantitative measurements of ventricular size, over time, can facilitate objective comparison, automated tools for calculating ventricular volume are not structured for clinical use. The authors aimed to develop a fully automated deep learning (DL) model for pediatric cerebral ventricle segmentation and volume calculation for widespread clinical implementation across multiple hospitals.

METHODS

The study cohort consisted of 200 children with obstructive hydrocephalus from four pediatric hospitals, along with 199 controls. Manual ventricle segmentation and volume calculation values served as “ground truth” data. An encoder-decoder convolutional neural network architecture, in which T2-weighted MR images were used as input, automatically delineated the ventricles and output volumetric measurements. On a held-out test set, segmentation accuracy was assessed using the Dice similarity coefficient (0 to 1) and volume calculation was assessed using linear regression. Model generalizability was evaluated on an external MRI data set from a fifth hospital. The DL model performance was compared against FreeSurfer research segmentation software.

RESULTS

Model segmentation performed with an overall Dice score of 0.901 (0.946 in hydrocephalus, 0.856 in controls). The model generalized to external MR images from a fifth pediatric hospital with a Dice score of 0.926. The model was more accurate than FreeSurfer, with faster operating times (1.48 seconds per scan).

CONCLUSIONS

The authors present a DL model for automatic ventricle segmentation and volume calculation that is more accurate and rapid than currently available methods. With near-immediate volumetric output and reliable performance across institutional scanner types, this model can be adapted to the real-time clinical evaluation of hydrocephalus and improve clinician workflow.

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Dang Do Thanh Can, Jacob R. Lepard, Nguyen Minh Anh, Pham Anh Tuan, Tran Diep Tuan, Vo Tan Son, John H. Grant, and James M. Johnston

OBJECTIVE

There is a global deficit of pediatric neurosurgical care, and the epidemiology and overall surgical care for craniosynostosis is not well characterized at the global level. This study serves to highlight the details and early surgical results of a neurosurgical educational partnership and subsequent local scale-up in craniosynostosis correction.

METHODS

A prospective case series was performed with inclusion of all patients undergoing correction of craniosynostosis by extensive cranial vault remodeling at Children’s Hospital 2, Ho Chi Minh City, Vietnam, between January 1, 2015, and December 31, 2019.

RESULTS

A total of 76 patients were included in the study. The group was predominantly male, with a male-to-female ratio of 3.3:1. Sagittal synostosis was the most common diagnosis (50%, 38/76), followed by unilateral coronal (11.8%, 9/76), bicoronal (11.8%, 9/76), and metopic (7.9%, 6/76). The most common corrective technique was anterior cranial vault remodeling (30/76, 39.4%) followed by frontoorbital advancement (34.2%, 26/76). The overall mean operative time was 205.8 ± 38.6 minutes, and the estimated blood loss was 176 ± 89.4 mL. Eleven procedures were complicated by intraoperative durotomy (14.5%, 11/76) without any damage of dural venous sinuses or brain tissue. Postoperatively, 4 procedures were complicated by wound infection (5.3%, 4/76), all of which required operative wound debridement. There were no neurological complications or postoperative deaths. One patient required repeat reconstruction due to delayed intracranial hypertension. There was no loss to follow-up. All patients were followed at outpatient clinic, and the mean follow-up period was 32.3 ± 18.8 months postoperatively.

CONCLUSIONS

Surgical care for pediatric craniosynostosis can be taught and sustained in the setting of collegial educational partnerships with early capability for high surgical volume and safe outcomes. In the setting of the significant deficit in worldwide pediatric neurosurgical care, this study provides an example of the feasibility of such relationships in addressing this unmet need.

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Mark R. Lovell, Michael W. Collins, Grant L. Iverson, Melvin Field, Joseph C. Maroon, Robert Cantu, Kenneth Podell, John W. Powell, Mark Belza, and Freddie H. Fu

Object. A computerized neuropsychological test battery was conducted to evaluate memory dysfunction and self-reporting of symptoms in a group of high school athletes who had suffered concussion.

Methods. Neuropsychological performance prior to and following concussion was compared with the test performance of an age-matched control group. Potentially important diagnostic markers of concussion severity are discussed and linked to recovery within the 1st week of injury.

Conclusions. High school athletes who had suffered mild concussion demonstrated significant declines in memory processes relative to a noninjured control group. Statistically significant differences between preseason and postinjury memory test results were still evident in the concussion group at 4 and 7 days postinjury. Self-reported neurological symptoms such as headache, dizziness, and nausea resolved by Day 4. Duration of on-field mental status changes such as retrograde amnesia and posttraumatic confusion was related to the presence of memory impairment at 36 hours and 4 and 7 days post-injury and was also related to slower resolution of self-reported symptoms. The results of this study suggest that caution should be exercised in returning high school athletes to the playing field following concussion. On-field mental status changes appear to have prognostic utility and should be taken into account when making return-to-play decisions following concussion. Athletes who exhibit on-field mental status changes for more than 5 minutes have longer-lasting postconcussion symptoms and memory decline.

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Michael C. Jin, Jonathon J. Parker, Laura M. Prolo, Adela Wu, Casey H. Halpern, Gordon Li, John K. Ratliff, Summer S. Han, Stephen L. Skirboll, and Gerald A. Grant

OBJECTIVE

The natural history of seizure risk after brain tumor resection is not well understood. Identifying seizure-naive patients at highest risk for postoperative seizure events remains a clinical need. In this study, the authors sought to develop a predictive modeling strategy for anticipating postcraniotomy seizures after brain tumor resection.

METHODS

The IBM Watson Health MarketScan Claims Database was canvassed for antiepileptic drug (AED)– and seizure-naive patients who underwent brain tumor resection (2007–2016). The primary event of interest was short-term seizure risk (within 90 days postdischarge). The secondary event of interest was long-term seizure risk during the follow-up period. To model early-onset and long-term postdischarge seizure risk, a penalized logistic regression classifier and multivariable Cox regression model, respectively, were built, which integrated patient-, tumor-, and hospitalization-specific features. To compare empirical seizure rates, equally sized cohort tertiles were created and labeled as low risk, medium risk, and high risk.

RESULTS

Of 5470 patients, 983 (18.0%) had a postdischarge-coded seizure event. The integrated binary classification approach for predicting early-onset seizures outperformed models using feature subsets (area under the curve [AUC] = 0.751, hospitalization features only AUC = 0.667, patient features only AUC = 0.603, and tumor features only AUC = 0.694). Held-out validation patient cases that were predicted by the integrated model to have elevated short-term risk more frequently developed seizures within 90 days of discharge (24.1% high risk vs 3.8% low risk, p < 0.001). Compared with those in the low-risk tertile by the long-term seizure risk model, patients in the medium-risk and high-risk tertiles had 2.13 (95% CI 1.45–3.11) and 6.24 (95% CI 4.40–8.84) times higher long-term risk for postdischarge seizures. Only patients predicted as high risk developed status epilepticus within 90 days of discharge (1.7% high risk vs 0% low risk, p = 0.003).

CONCLUSIONS

The authors have presented a risk-stratified model that accurately predicted short- and long-term seizure risk in patients who underwent brain tumor resection, which may be used to stratify future study of postoperative AED prophylaxis in highest-risk patient subpopulations.

Free access

Dang Do Thanh Can, Jacob R. Lepard, Nguyen Minh Anh, Pham Anh Tuan, Tran Diep Tuan, Vo Tan Son, John H. Grant, and James M. Johnston

OBJECTIVE

There is a global deficit of pediatric neurosurgical care, and the epidemiology and overall surgical care for craniosynostosis is not well characterized at the global level. This study serves to highlight the details and early surgical results of a neurosurgical educational partnership and subsequent local scale-up in craniosynostosis correction.

METHODS

A prospective case series was performed with inclusion of all patients undergoing correction of craniosynostosis by extensive cranial vault remodeling at Children’s Hospital 2, Ho Chi Minh City, Vietnam, between January 1, 2015, and December 31, 2019.

RESULTS

A total of 76 patients were included in the study. The group was predominantly male, with a male-to-female ratio of 3.3:1. Sagittal synostosis was the most common diagnosis (50%, 38/76), followed by unilateral coronal (11.8%, 9/76), bicoronal (11.8%, 9/76), and metopic (7.9%, 6/76). The most common corrective technique was anterior cranial vault remodeling (30/76, 39.4%) followed by frontoorbital advancement (34.2%, 26/76). The overall mean operative time was 205.8 ± 38.6 minutes, and the estimated blood loss was 176 ± 89.4 mL. Eleven procedures were complicated by intraoperative durotomy (14.5%, 11/76) without any damage of dural venous sinuses or brain tissue. Postoperatively, 4 procedures were complicated by wound infection (5.3%, 4/76), all of which required operative wound debridement. There were no neurological complications or postoperative deaths. One patient required repeat reconstruction due to delayed intracranial hypertension. There was no loss to follow-up. All patients were followed at outpatient clinic, and the mean follow-up period was 32.3 ± 18.8 months postoperatively.

CONCLUSIONS

Surgical care for pediatric craniosynostosis can be taught and sustained in the setting of collegial educational partnerships with early capability for high surgical volume and safe outcomes. In the setting of the significant deficit in worldwide pediatric neurosurgical care, this study provides an example of the feasibility of such relationships in addressing this unmet need.

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Allen L. Ho, John G. D. Cannon, Jyodi Mohole, Arjun V. Pendharkar, Eric S. Sussman, Gordon Li, Michael S. B. Edwards, Samuel H. Cheshier, and Gerald A. Grant

OBJECTIVE

Topical antimicrobial compounds are safe and can reduce cost and complications associated with surgical site infections (SSIs). Topical vancomycin has been an effective tool for reducing SSIs following routine neurosurgical procedures in the spine and following adult craniotomies. However, widespread adoption within the pediatric neurosurgical community has not yet occurred, and there are no studies to report on the safety and efficacy of this intervention. The authors present the first institution-wide study of topical vancomycin following open craniotomy in the pediatric population.

METHODS

In this retrospective study the authors reviewed all open craniotomies performed over a period from 05/2014 to 12/2016 for topical vancomycin use, SSIs, and clinical variables associated with SSI. Topical vancomycin was utilized as an infection prophylaxis and was applied as a liquid solution following replacement of a bone flap or after dural closure when no bone flap was reapplied.

RESULTS

Overall, 466 consecutive open craniotomies were completed between 05/2014 and 12/2016, of which 43% utilized topical vancomycin. There was a 1.5% SSI rate in the nontopical cohort versus 0% in the topical vancomycin cohort (p = 0.045). The number needed to treat was 66. There were no significant differences in risk factors for SSI between cohorts. There were no complications associated with topical vancomycin use.

CONCLUSIONS

Routine topical vancomycin administration during closure of open craniotomies can be a safe and effective tool for reducing SSIs in the pediatric neurosurgical population.