Awake craniotomy for supratentorial tumors or epileptogenic lesions in pediatric patients: a 16-year retrospective cohort study

OBJECTIVE

Awake craniotomy with intraoperative mapping is the widely accepted procedure for adult patients undergoing supratentorial tumor or epileptogenic focus resection near eloquent cortex. In children, awake craniotomies are notably less common due to concerns for compliance and emotional or psychological repercussions. Despite this, successfully tolerated awake craniotomies have been reported in patients as young as 8 years of age, with success rates comparable to those of adults. The authors sought to describe their experience with pediatric awake craniotomies, including insight regarding feasibility and outcomes.

METHODS

A retrospective review was completed for all pediatric (age < 18 years) patients at Children's Wisconsin for whom an awake craniotomy was attempted from January 2004 until March 2020. Institutional review board approval was granted.

RESULTS

Candidate patients had intact verbal ability, cognitive profile, and no considerable anxiety concerns during neuropsychology assessment. Nine patients presented with seizure. Five patients were diagnosed with tumor and secondary epilepsy, 3 with tumor only, and 3 with epilepsy only. All patients who underwent preoperative functional MRI successfully completed and tolerated testing paradigms. A total of 12 awake craniotomies were attempted in 11 patients, with 1 procedure aborted due to intraoperative bleeding. One patient had a repeat procedure. The mean patient age was 15.5 years (range 11.5-17.9 years). All patients returned to or maintained baseline motor and speech functions by the latest follow-up (range 14-130 months). Temporary deficits included transient speech errors, mild decline in visuospatial reasoning, leg numbness, and expected hemiparesis. Of the 8 patients with a diagnosis of epilepsy prior to surgery, 7 patients achieved Engel class I designation at the 1-year follow-up, 6 of whom remained in class I at the latest follow-up.

CONCLUSIONS

This study analyzes one of the largest cohorts of pediatric patients who underwent awake craniotomy for maximal safe resection of tumor or epileptogenic lesions. For candidate patients, awake craniotomy is safe, feasible, and effective in carefully selected children.

Neural representations of self-perception of voice: An intracortical evoked potential analysis based on an adolescent with right temporal lobe epilepsy

INTRODUCTION

The neural bases for language perception have been studied elsewhere using Transcranial Magnetic Stimulation, functional Magnetic Resonance Imaging and Direct Cortical Stimulation. However, to our knowledge, there is no previous report about a patient identifying the change in his voice tone, speed, and prosody because of right temporal cortical stimulation. Nor has there been a cortico-cortical evoked potential (CCEP) assessment of the network underlying this process.

CASE REPORT

We present CCEP from a patient with right focal refractory temporal lobe epilepsy of tumoral etiology who reported changes in the perception of his own speech prosody during stimulation. This report will serve as a complement to the understanding of the neural networks of language and prosody.

CONCLUSION

The present report shows that right superior temporal gyrus, transverse temporal gyrus, right amygdala, hippocampus, and fusiform gyrus (FG) are part of the neural network subjacent to own human voice perception.

Magnetic resonance imaging-guided stereotactic laser ablation therapy for the treatment of pediatric epilepsy: a retrospective multiinstitutional study

OBJECTIVE

The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children.

METHODS

Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed.

RESULTS

A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications.

CONCLUSIONS

SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

Magnetic resonance imaging-guided laser interstitial thermal therapy for complete corpus callosotomy: technique and 1-year outcomes. Patient series

BACKGROUND

Magnetic resonance imaging (MRI)-guided stereotactic laser interstitial thermal therapy (LITT) is a minimally invasive technique that has been described for the treatment of certain forms of epilepsy through partial or complete callosotomy, with few cases describing single-stage complete LITT callosotomy. The authors aimed to demonstrate this technique's feasibility and efficacy through description of the technique and 1-year outcomes in 3 cases of single-stage complete LITT callosotomy in patients with anatomically normal corpa callosa (CCs).

OBSERVATIONS

The patients were aged 14-27 years and experienced atonic seizures. Completeness of callosotomy was determined from MRI scans obtained >3 months after LITT procedures. The estimated ablations of the CC were 94%, 89%, and 100%, respectively. The second patient had a catheter breach the lateral ventricle, resulting in the lowest estimated percentage of ablation in this series (89%), with minimal atonic seizure reduction. The first patient had significant reduction in atonic seizure frequency, and the third patient had complete resolution of atonic seizures. None of the patients experienced any long-term complications. Intensive care length of stay was 1 night for each patient, and total length of stay was between 2 and 7 nights. Postoperative follow-up was between 14 and 18 months.

LESSONS

Complete laser callosotomy is achievable and is a safe alternative to microsurgical or endoscopic approaches.

Connectomic profiling and Vagus nerve stimulation Outcomes Study (CONNECTiVOS): a prospective observational protocol to identify biomarkers of seizure response in children and youth

INTRODUCTION

Vagus nerve stimulation (VNS) is a neuromodulation therapy that can reduce the seizure burden of children with medically intractable epilepsy. Despite the widespread use of VNS to treat epilepsy, there are currently no means to preoperatively identify patients who will benefit from treatment. The objective of the present study is to determine clinical and neural network-based correlates of treatment outcome to better identify candidates for VNS therapy.

METHODS AND ANALYSIS

In this multi-institutional North American study, children undergoing VNS and their caregivers will be prospectively recruited. All patients will have documentation of clinical history, physical and neurological examination and video electroencephalography as part of the standard clinical workup for VNS. Neuroimaging data including resting-state functional MRI, diffusion-tensor imaging and magnetoencephalography will be collected before surgery. MR-based measures will also be repeated 12 months after implantation. Outcomes of VNS, including seizure control and health-related quality of life of both patient and primary caregiver, will be prospectively measured up to 2 years postoperatively. All data will be collected electronically using Research Electronic Data Capture.

ETHICS AND DISSEMINATION

This study was approved by the Hospital for Sick Children Research Ethics Board (REB number 1000061744). All participants, or substitute decision-makers, will provide informed consent prior to be enrolled in the study. Institutional Research Ethics Board approval will be obtained from each additional participating site prior to inclusion. This study is funded through a Canadian Institutes of Health Research grant (PJT-159561) and an investigator-initiated funding grant from LivaNova USA (Houston, TX; FF01803B IIR).

Early implementation of stereoelectroencephalography in children: a multiinstitutional case series

OBJECTIVE

Pediatric stereoelectroencephalography (SEEG) has been increasingly performed in the United States, with published literature being limited primarily to large single-center case series. The purpose of this study was to evaluate the experience of pediatric epilepsy centers, where the technique has been adopted in the last several years, via a multicenter case series studying patient demographics, outcomes, and complications.

METHODS

A retrospective cohort methodology was used based on the STROBE criteria. ANOVA was used to evaluate for significant differences between the means of continuous variables among centers. Dichotomous outcomes were assessed between centers using a univariate and multivariate logistic regression.

RESULTS

A total of 170 SEEG insertion procedures were included in the study from 6 different level 4 pediatric epilepsy centers. The mean patient age at time of SEEG insertion was 12.3 ± 4.7 years. There was no significant difference between the mean age at the time of SEEG insertion between centers (p = 0.3). The mean number of SEEG trajectories per patient was 11.3 ± 3.6, with significant variation between centers (p < 0.001). Epileptogenic loci were identified in 84.7% of cases (144/170). Patients in 140 cases (140/170, 82.4%) underwent a follow-up surgical intervention, with 47.1% (66/140) being seizure free at a mean follow-up of 30.6 months. An overall postoperative hemorrhage rate of 5.3% (9/170) was noted, with patients in 4 of these cases (4/170, 2.4%) experiencing a symptomatic hemorrhage and patients in 3 of these cases (3/170, 1.8%) requiring operative evacuation of the hemorrhage. There were no mortalities or long-term complications.

CONCLUSIONS

As the first multicenter case series in pediatric SEEG, this study has aided in establishing normative practice patterns in the application of a novel surgical technique, provided a framework for anticipated outcomes that is generalizable and useful for patient selection, and allowed for discussion of what is an acceptable complication rate relative to the experiences of multiple institutions.

Determination of language dominance in pediatric patients with epilepsy for clinical decision-making: Correspondence of intracarotid amobarbitol procedure and fMRI modalities

Identification of the language dominant hemisphere is an essential part of the evaluation of potential pediatric epilepsy surgery patients. Historically, language dominance has been determined using the intracarotid amobarbitol procedure (IAP), but use of functional Magnetic Resonance Imaging (fMRI) scanning is becoming more common. Few studies examine the correspondence between fMRI and IAP in pediatric samples. The current study examined the agreement of hemispheric lateralization as determined by fMRI and IAP in a consecutive sample of 10 pediatric patients with epilepsy evaluated for epilepsy surgery. Data showed a strong correlation between IAP and fMRI lateralilty indices (r=.91) and 70% agreement in determination of hemispheric dominance, despite increased demonstration of bilateral or atypical language representation in this pediatric sample. Clinical implications and interpretation challenges are discussed.

Radiological Imaging Transmission via Smartphones by Neurosurgery Residents in the United States

BACKGROUND

Neurosurgery requires the communication of radiological imaging. Smartphones are increasingly used for this purpose because of the efficiency and convenience of integrated cameras and native Multimedia Messaging Service (MMS) functionality. There is inconsistency among hospitals regarding policies addressing this use as it relates to the Health Insurance Portability and Accountability Act (HIPAA) Privacy Rule. Some hospitals offer a HIPAA-compliant secure messaging application (SMA) as a substitute. The authors hypothesized that the use of smartphones for sharing radiological imaging would be commonplace among residents. We sought to characterize usage patterns, resident awareness of policies and HIPPA, and the effectiveness of SMAs as a means of avoiding HIPAA violations.

METHODS

An electronic dynamic questionnaire was sent to all 116 Accreditation Council for Graduate Medical Education-accredited US neurosurgery residency program directors and coordinators to be forwarded to their residents.

RESULTS

A total of 100 responses were received, representing 49 residency programs. Ninety-two (92%) residents reported using MMS to transmit radiological imaging. Twenty-six (26%) reported doing so with patient identifiers. Roughly half (48%) of residents were unaware of policies regarding imaging transmission via MMS at their institutions. Among the 17 (35%) programs providing SMAs, only 3 of 27 (11%) residents in these programs did not use MMS for image transmission.

CONCLUSIONS

The data suggest that there is widespread resident use of MMS for image transmission, regardless of policy and the availability of alternative HIPAA-compliant applications. Knowledge of local institutional policies and HIPAA privacy rules is poor. Alternative strategies are needed to prevent HIPAA-noncompliant transmission of imaging by residents.

Clonally Focused Public and Private T Cells in Resected Brain Tissue From Surgeries to Treat Children With Intractable Seizures

Using a targeted transcriptomics approach, we have analyzed resected brain tissue from a cohort of 53 pediatric epilepsy surgery cases, and have found that there is a spectrum of involvement of both the innate and adaptive immune systems as evidenced by the differential expression of immune-specific genes in the affected brain tissue. The specimens with the highest expression of immune-specific genes were from two Rasmussen encephalitis cases, which is known to be a neuro-immunological disease, but also from tuberous sclerosis complex (TSC), focal cortical dysplasia, and hemimegalencephaly surgery cases. We obtained T cell receptor (TCR) Vβ chain sequence data from brain tissue and blood from patients with the highest levels of T cell transcripts. The clonality indices and the frequency of the top 50 Vβ clonotypes indicated that T cells in the brain were clonally restricted. The top 50 Vβ clonotypes comprised both public and private (patient specific) clonotypes, and the TCR Vβ chain third complementarity region (CDR3) of the most abundant public Vβ clonotype in each brain sample was strikingly similar to a CDR3 that recognizes an immunodominant epitope in either human cytomegalovirus or Epstein Barr virus, or influenza virus A. We found that the frequency of 14 of the top 50 brain Vβ clonotypes from a TSC surgery case had significantly increased in brain tissue removed to control recurrent seizures 11 months after the first surgery. Conversely, we found that the frequency in the blood of 18 of the top 50 brain clonotypes from a second TSC patient, who was seizure free, had significantly decreased 5 months after surgery indicating that T cell clones found in the brain had contracted in the periphery after removal of the brain area associated with seizure activity and inflammation. However, the frequency of a public and a private clonotype significantly increased in the brain after seizures recurred and the patient underwent a second surgery. Combined single cell gene expression and TCR sequencing of brain-infiltrating leukocytes from the second surgery showed that the two clones were CD8 effector T cells, indicating that they are likely to be pathologically relevant.

Development of best practices in the utilization and implementation of pediatric cervical spine traction: a modified Delphi study

OBJECTIVE

Cervical traction in pediatric patients is an uncommon but invaluable technique in the management of cervical trauma and deformity. Despite its utility, little empirical evidence exists to guide its implementation, with most practitioners employing custom or modified adult protocols. Expert-based best practices may improve the care of children undergoing cervical traction. In this study, the authors aimed to build consensus and establish best practices for the use of pediatric cervical traction in order to enhance its utilization, safety, and efficacy.

METHODS

A modified Delphi method was employed to try to identify areas of consensus regarding the utilization and implementation of pediatric cervical spine traction. A literature review of pediatric cervical traction was distributed electronically along with a survey of current practices to a group of 20 board-certified pediatric neurosurgeons and orthopedic surgeons with expertise in the pediatric cervical spine. Sixty statements were then formulated and distributed to the group. The results of the second survey were discussed during an in-person meeting leading to further consensus. Consensus was defined as ≥ 80% agreement on a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree).

RESULTS

After the initial round, consensus was achieved with 40 statements regarding the following topics: goals, indications, and contraindications of traction (12), pretraction imaging (6), practical application and initiation of various traction techniques (8), protocols in trauma and deformity patients (8), and management of traction-related complications (6). Following the second round, an additional 9 statements reached consensus related to goals/indications/contraindications of traction (4), related to initiation of traction (4), and related to complication management (1). All participants were willing to incorporate the consensus statements into their practice.

CONCLUSIONS

In an attempt to improve and standardize the use of cervical traction in pediatric patients, the authors have identified 49 best-practice recommendations, which were generated by reaching consensus among a multidisciplinary group of pediatric spine experts using a modified Delphi technique. Further study is required to determine if implementation of these practices can lead to reduced complications and improved outcomes for children.

Vacuum-assisted elevation of pediatric ping-pong skull fractures: a case series and technical note

OBJECTIVE

The management of children with ping-pong skull fractures may include observation, nonsurgical treatments, or surgical intervention depending on the age, clinical presentation, imaging findings, and cosmetic appearance of the patient. There have been 16 publications on nonsurgical treatment using negative pressure with various devices. Herein, the authors report their experience with vacuum-assisted elevation of ping-pong skull fractures and evaluate the variables affecting procedural outcomes.

METHODS

The authors performed a retrospective chart review of all ping-pong skull fractures treated via vacuum-assisted elevation at the Children's Hospital of Wisconsin between 2013 and 2017. Data collected included patient age, head circumference, mode of injury, time to presentation, imaging findings, procedural details, treatment outcomes, and complications.

RESULTS

Four neonates and 5 infants underwent vacuum-assisted elevation of moderate to severe ping-pong skull fractures during the study period. Modes of injury included birth-related trauma, falls, and blunt trauma. All patients had normal neurological examination findings and no evidence of intracranial hemorrhage. All fractures were deemed severe enough to require elevation by the treating neurosurgeon. All fractures involved the parietal bone. Skull depressions ranged from 23 to 62 mm in diameter and from 4 to 14 mm in depth. Bone thickness ranged from 0.6 to 1.8 mm. The time from fracture to intervention ranged from 7 hours to 8 days. The Kiwi OmniCup vacuum delivery system was used in all cases. Negative pressures were increased sequentially to a maximum of 500 mm Hg. A greater number of sequential vacuum applications was required for patients with a skull thickness greater than 1 mm at the site of depression and for those undergoing treatment more than 72 hours from fracture onset. Successful fracture elevation was attained in 7 of 9 patients. Two patients required subsequent surgical elevation of their fractures. Postprocedure imaging studies revealed no evidence of complications.

CONCLUSIONS

Increasing bone thickness and time from fracture onset to intervention appeared to be the greatest limiting factors to the successful elevation of moderate to severe ping-pong fractures via this vacuum-assisted approach. This procedure is a well-tolerated option that should be considered prior to performing an open repair in cases deemed to require fracture elevation. Future efforts will focus on larger-volume studies to better delineate inclusion and exclusion criteria, and volumetric analysis for better fracture-to-suction device customization.

Multiple hippocampal transections for refractory pediatric mesial temporal lobe epilepsy: seizure and neuropsychological outcomes

OBJECTIVE

Temporal lobe epilepsy (TLE) is the most common focal epilepsy across adult and pediatric age groups. It is also the most amenable to surgery, with excellent long-term seizure outcome. Most TLE cases have an epileptogenic zone in the mesial temporal structures, namely the hippocampus. Resecting the dominant hippocampus has been shown to be associated with significant verbal memory deficits, especially in patients with intact verbal memory scores presurgically. Multiple hippocampal transection (MHT) is a relatively new surgical technique designed to interrupt the longitudinal hippocampal circuitry involved in seizure propagation yet preserve the circular fibers involved in memory function. This technique has been used to treat mesial TLE in both dominant- and nondominant-hemisphere cases, almost exclusively in adults. It has been applied to normal and sclerotic hippocampi.

METHODS

In this study, information on 3 pediatric patients who underwent MHT for mesial TLE at Children's Wisconsin between 2017 and 2018 is included. Clinical, electroencephalographic, and neuropsychological features and outcomes are described in detail.

RESULTS

MRI revealed a tumor in the amygdala with a normal hippocampus in 1 patient and hippocampal sclerosis in 2 patients. All patients underwent stereoelectroencephalography confirming the involvement of the hippocampus in seizure onset. MHTs were completed under intraoperative monitoring, with amygdala and temporal tip resection in all patients due to early spread to these regions. All patients had excellent seizure outcomes at 1 year, and 2 of the 3 patients remain seizure free at last follow-up (range 20-36 months), all with stable or improved neuropsychological profiles, including verbal memory.

CONCLUSIONS

MHT is a relatively new surgical procedure designed to preserve essential memory circuitry while disrupting seizure propagation pathways in the hippocampus. A growing body of literature shows good seizure and neuropsychological results, but mainly in adults. This is the first series of MHTs used exclusively in children at one medical center, showcasing excellent seizure control and preservation of neuropsychological functioning. One of the patients is also the first described to have MHT in the setting of an amygdalar tumor abutting the hippocampus, further expanding the pathological setting in which MHT can be used effectively.

Low risk of clinically important central nervous system dysraphism in a cohort study of 69 patients with isolated aplasia cutis congenita of the head

BACKGROUND

Aplasia cutis congenita of the head may be associated with underlying fusion defects in the skin, soft tissues, muscle, or bone. The risk of central nervous system dysraphism in patients with aplasia cutis congenita is not known; however, knowledge of underlying structural defects can inform management considerations.

METHODS

This retrospective review investigated the risk of cranial central nervous system dysraphism in children presenting with aplasia cutis congenita of the head, who presented between 1/1/2000 and 6/15/2016. Inclusion criteria were subjects with aplasia cutis congenita of the head who received CT or MR imaging of the head.

RESULTS

We identified a total of 69 subjects with aplasia cutis congenita affecting the head and who received imaging. The most common location of the aplasia cutis congenita lesion was the vertex scalp (49.3%). The hair collar sign was present in 27.5% of patients. Twelve of 69 patients (17.4%) demonstrated abnormalities of the bone, vasculature, or brain on head imaging. Only one patient had a diagnosis of encephalocele that required neurosurgical intervention. There was a statistical association between the hair collar sign and the presence of abnormal imaging findings (P = .029), with a negative predictive value of 89.4%.

CONCLUSIONS

The incidence of central nervous system dysraphism in patients with aplasia cutis congenita of the head appears to be low, and it may not be necessary to image the head of each child presenting with this skin lesion. The hair collar sign may be a marker of underlying defects.

Magnetic resonance-guided stereotactic laser ablation therapy for the treatment of pediatric brain tumors: a multiinstitutional retrospective study

OBJECTIVE

This study aimed to assess the safety and efficacy of MR-guided stereotactic laser ablation (SLA) therapy in the treatment of pediatric brain tumors.

METHODS

Data from 17 North American centers were retrospectively reviewed. Clinical, technical, and radiographic data for pediatric patients treated with SLA for a diagnosis of brain tumor from 2008 to 2016 were collected and analyzed.

RESULTS

A total of 86 patients (mean age 12.2 ± 4.5 years) with 76 low-grade (I or II) and 10 high-grade (III or IV) tumors were included. Tumor location included lobar (38.4%), deep (45.3%), and cerebellar (16.3%) compartments. The mean follow-up time was 24 months (median 18 months, range 3-72 months). At the last follow-up, the volume of SLA-treated tumors had decreased in 80.6% of patients with follow-up data. Patients with high-grade tumors were more likely to have an unchanged or larger tumor size after SLA treatment than those with low-grade tumors (OR 7.49, p = 0.0364). Subsequent surgery and adjuvant treatment were not required after SLA treatment in 90.4% and 86.7% of patients, respectively. Patients with high-grade tumors were more likely to receive subsequent surgery (OR 2.25, p = 0.4957) and adjuvant treatment (OR 3.77, p = 0.1711) after SLA therapy, without reaching significance. A total of 29 acute complications in 23 patients were reported and included malpositioned catheters (n = 3), intracranial hemorrhages (n = 2), transient neurological deficits (n = 11), permanent neurological deficits (n = 5), symptomatic perilesional edema (n = 2), hydrocephalus (n = 4), and death (n = 2). On long-term follow-up, 3 patients were reported to have worsened neuropsychological test results. Pre-SLA tumor volume, tumor location, number of laser trajectories, and number of lesions created did not result in a significantly increased risk of complications; however, the odds of complications increased by 14% (OR 1.14, p = 0.0159) with every 1-cm3 increase in the volume of the lesion created.

CONCLUSIONS

SLA is an effective, minimally invasive treatment option for pediatric brain tumors, although it is not without risks. Limiting the volume of the generated thermal lesion may help decrease the incidence of complications.

Examining the Utility of Resective Epilepsy Surgery in Children With Electrical Status Epilepticus in Sleep: Long Term Clinical and Electrophysiological Outcomes

Background: Electrical Status Epilepticus in Sleep (ESES) is an epileptic encephalopathy syndrome characterized by infrequent clinical seizures and prominent interictal burden during slow wave sleep associated with cognitive deficits and behavioral dysfunction. Medical treatment with anti-epileptic drugs is often unsuccessful. Resective surgery may be a valuable option in carefully selected patients. This case series aims to describe the indications, long term results and utility of resective surgery for ESES.

Methods: Information on 14 patients who underwent surgery for epilepsy and ESES at the Children's Hospital of Wisconsin between 2007 and 2017 is included. Clinical, electrographic and neuropsychological features and outcomes are described in detail.

Results: The most common pathology was encephalomalacia due to perinatal middle cerebral artery stoke (5/14). Twelve patients had imaging findings of perinatal pathologies; however, two patients had normal magnetic resonance imaging. Surgery was performed to control refractory epilepsy in eight patients. Six patients had no clinical seizures for 1–6 years prior to surgery, one of which had no known clinical seizures at all. All showed cognitive declines (6/14) or impairment (8/14) on neuropsychological assessments, and surgery was suggested to minimize further cognitive declines. The most common surgical procedure was hemispherotomy (10/14). Temporo-parieto-occipital disconnection, frontal lobectomy, parieto-occipital resection, and limited corticectomy were also used, with good outcomes for the first three procedures. Clinical follow up mean was 4.4 years and 12 patients had excellent seizure outcome. Electroencephalography (EEG) follow up mean was 3 years and ESES resolved in 12/14 patients. All patients completed post-surgical neuropsychological evaluation with mean follow-up of 17.46 months.

Conclusions: Resective surgery is an effective treatment for selected cases of ESES, producing long term seizure freedom, resolution of ESES and stabilization of cognitive and behavioral functioning in most patients. Our case series is the largest single center cohort description addressing resective surgery for ESES. Outcomes in this sample suggest that good long-term seizure, EEG and cognitive/behavioral outcomes can be achieved in patients with normal brain imaging and in limited lobar or multi-lobar resections. Moreover, patients with ESES and very infrequent clinical seizures can benefit from surgery with stabilization of cognitive and behavioral functioning.

Stereotactic laser ablation for nonlesional cingulate epilepsy: case report

Stereotactic laser ablation (SLA) is being increasingly used to treat refractory focal epilepsy, especially mesial temporal lobe epilepsy. However, emerging evidence suggests it can be used for extratemporal lobe epilepsy as well.The authors report the case of a 17-year-old male who presented with refractory nocturnal seizures characterized by bilateral arms stiffening or rhythmic jerking lasting several seconds. Semiology suggested an epileptogenic zone close to one of the supplementary sensory motor areas. Electroencephalography showed seizures arising from the central region without consistent lateralization. Brain imaging showed no abnormality. An invasive evaluation using bilateral stereoelectroencephalography (SEEG) was utilized in 2 steps, first to establish the laterality of seizures, and second to further cover the mesial cingulate region of the right hemisphere. Seizures arose from the middle portion of the right cingulate gyrus. Extraoperative electrical mapping revealed that the seizure onset zone was adjacent to eloquent motor areas. SLA targeting the right midcingulate gyrus was performed. The patient has remained seizure free since immediately after the procedure with no postoperative deficits (follow-up of 17 months).This case highlights the utility of SEEG in evaluating difficult-to-localize, focal epilepsy. It also demonstrates that the use of SLA can be extended to nonlesional, extratemporal epilepsies.

Complications following pediatric cranioplasty after decompressive craniectomy: a multicenter retrospective study

OBJECTIVE In children, the repair of skull defects arising from decompressive craniectomy presents a unique set of challenges. Single-center studies have identified different risk factors for the common complications of cranioplasty resorption and infection. The goal of the present study was to determine the risk factors for bone resorption and infection after pediatric cranioplasty. METHODS The authors conducted a multicenter retrospective case study that included all patients who underwent cranioplasty to correct a skull defect arising from a decompressive craniectomy at 13 centers between 2000 and 2011 and were less than 19 years old at the time of cranioplasty. Prior systematic review of the literature along with expert opinion guided the selection of variables to be collected. These included: indication for craniectomy; history of abusive head trauma; method of bone storage; method of bone fixation; use of drains; size of bone graft; presence of other implants, including ventriculoperitoneal (VP) shunt; presence of fluid collections; age at craniectomy; and time between craniectomy and cranioplasty. RESULTS A total of 359 patients met the inclusion criteria. The patients' mean age was 8.4 years, and 51.5% were female. Thirty-eight cases (10.5%) were complicated by infection. In multivariate analysis, presence of a cranial implant (primarily VP shunt) (OR 2.41, 95% CI 1.17-4.98), presence of gastrostomy (OR 2.44, 95% CI 1.03-5.79), and ventilator dependence (OR 8.45, 95% CI 1.10-65.08) were significant risk factors for cranioplasty infection. No other variable was associated with infection. Of the 240 patients who underwent a cranioplasty with bone graft, 21.7% showed bone resorption significant enough to warrant repeat surgical intervention. The most important predictor of cranioplasty bone resorption was age at the time of cranioplasty. For every month of increased age the risk of bone flap resorption decreased by 1% (OR 0.99, 95% CI 0.98-0.99, p < 0.001). Other risk factors for resorption in multivariate models were the use of external ventricular drains and lumbar shunts. CONCLUSIONS This is the largest study of pediatric cranioplasty outcomes performed to date. Analysis included variables found to be significant in previous retrospective reports. Presence of a cranial implant such as VP shunt is the most significant risk factor for cranioplasty infection, whereas younger age at cranioplasty is the dominant risk factor for bone resorption.

Spheno-Orbital Aneurysmal Bone Cyst in a 10-Month-Old Infant

BACKGROUND

Aneurysmal bone cysts are benign bone lesions affecting long bones and vertebrae; only 2%-6% have cranial involvement, and even fewer show sphenoid or intraorbital involvement. Gross total resection is the treatment of choice.

CASE DESCRIPTION

A 10-month-old girl presented with unilateral proptosis and no neurologic deficits. Imaging studies revealed an extensive right-sided skull base cystic lesion centered on the sphenoid wing with extension into the orbit anteriorly and the pterygoid plates inferiorly. She underwent a modified osteoplastic orbitozygomatic craniotomy for resection of the extradural tumor. Postoperative imaging showed successful decompression of the intraorbital contents with no residual tumor. She remained neurologically intact and was discharged on postoperative day 2. Histologic examination revealed the lesion to be consistent with an aneurysmal bone cyst. At 3-month follow-up, her proptosis had resolved, neurologic examination was nonfocal, and there was no radiographic evidence of recurrence.

CONCLUSIONS

To our knowledge, this is the youngest patient reported to have a spheno-orbital aneurysmal bone cyst. Such lesions in this age group present practical management challenges. By using a modified osteoplastic orbitozygomatic craniotomy, we achieved a gross total resection with minimal brain retraction, avoided the need for plating and suturing at the orbital rim, maintained a vascularized bone flap that is less susceptible to infection, and maintained normal temporalis muscle anatomy with excellent cosmetic results.

Growth and alignment of the pediatric subaxial cervical spine following rigid instrumentation and fusion: a multicenter study of the Pediatric Craniocervical Society

OBJECTIVE The long-term effects of surgical fusion on the growing subaxial cervical spine are largely unknown. Recent cross-sectional studies have demonstrated that there is continued growth of the cervical spine through the teenage years. The purpose of this multicenter study was to determine the effects of rigid instrumentation and fusion on the growing subaxial cervical spine by investigating vertical growth, cervical alignment, cervical curvature, and adjacent-segment instability over time. METHODS A total of 15 centers participated in this multi-institutional retrospective study. Cases involving children less than 16 years of age who underwent rigid instrumentation and fusion of the subaxial cervical spine (C-2 and T-1 inclusive) with at least 1 year of clinical and radiographic follow-up were investigated. Charts were reviewed for clinical data. Postoperative and most recent radiographs, CT, and MR images were used to measure vertical growth and assess alignment and stability. RESULTS Eighty-one patients were included in the study, with a mean follow-up of 33 months. Ninety-five percent of patients had complete clinical resolution or significant improvement in symptoms. Postoperative cervical kyphosis was seen in only 4 patients (5%), and none developed a swan-neck deformity, unintended adjacent-level fusion, or instability. Of patients with at least 2 years of follow-up, 62% demonstrated growth across the fusion construct. On average, vertical growth was 79% (4-level constructs), 83% (3-level constructs), or 100% (2-level constructs) of expected growth. When comparing the group with continued vertical growth to the one without growth, there were no statistically significant differences in terms of age, sex, underlying etiology, surgical approach, or number of levels fused. CONCLUSIONS Continued vertical growth of the subaxial spine occurs in nearly two-thirds of children after rigid instrumentation and fusion of the subaxial spine. Failure of continued vertical growth is not associated with the patient's age, sex, underlying etiology, number of levels fused, or surgical approach. Further studies are needed to understand this dichotomy and determine the long-term biomechanical effects of surgery on the growing pediatric cervical spine.

Identifying Factors Predictive of Atlantoaxial Fusion Failure in Pediatric Patients: Lessons Learned From a Retrospective Pediatric Craniocervical Society Study

STUDY DESIGN

Multicenter retrospective cohort study with multivariate analysis.

OBJECTIVE

To determine factors predictive of posterior atlantoaxial fusion failure in pediatric patients.

SUMMARY OF BACKGROUND DATA

Fusion rates for pediatric posterior atlantoaxial arthrodesis have been reported to be high in single-center studies; however, factors predictive of surgical non-union have not been identified by a multicenter study.

METHODS

Clinical and surgical details for all patients who underwent posterior atlantoaxial fusion at seven pediatric spine centers from 1995 to 2014 were retrospectively recorded. The primary outcome was surgical failure, defined as either instrumentation failure or fusion failure seen on either plain x-ray or computed tomography scan. Multiple logistic regression analysis was undertaken to identify clinical and technical factors predictive of surgical failure.

RESULTS

One hundred thirty-one patients met the inclusion criteria and were included in the analysis. Successful fusion was seen in 117 (89%) of the patients. Of the 14 (11%) patients with failed fusion, the cause was instrumentation failure in 3 patients (2%) and graft failure in 11 (8%). Multivariate analysis identified Down syndrome as the single factor predictive of fusion failure (odds ratio 14.6, 95% confidence interval [3.7-64.0]).

CONCLUSION

This retrospective analysis of a multicenter cohort demonstrates that although posterior pediatric atlantoaxial fusion success rates are generally high, Down syndrome is a risk factor that significantly predicts the possibility of surgical failure.

LEVEL OF EVIDENCE

3.

Split laminotomy versus conventional laminotomy: postoperative outcomes in pediatric patients

OBJECTIVE Split laminotomy is a technique for accessing the spinal canal from the posterior midline that minimizes muscle dissection and bone removal. Benefits of this approach in minimizing postoperative pain and muscle atrophy in the adult population have been reported, but pediatric data are limited. Herein, the authors evaluate the benefits of the split laminotomy technique in pediatric patients. METHODS Data obtained in patients who underwent posterior spine surgery at Children's Hospital of Wisconsin for an intradural midline pathology between April 2008 and June 2015 were reviewed retrospectively. Each patient was assigned to one of two groups, the split-laminotomy or conventional-laminotomy group. The primary outcomes assessed were mean daily pain score, total opioid use over a period of 72 hours after surgery, and the degree of paraspinal muscle atrophy and fat infiltration found on short-term (1-4 months) and long-term (1-4 years) follow-up spine MRI studies. RESULTS A total of 117 patients underwent lumbar-level surgery (83 conventional laminotomy, 34 split laminotomy), and 8 patients underwent thoracic-level surgery (4 in each group). No significant difference in the mean daily pain scores between groups was found. The daily opioid use was significantly lower in the split-laminotomy group on postoperative day 0 (POD0) and POD1 but not on POD2 (p = 0.01, 0.01, and 0.10, respectively). The total opioid use over the 72-hour postoperative period was significantly lower in the split-laminotomy group (p = 0.0008). The fat/muscle ratio was significantly higher in both the short-term and long-term follow-up periods in the conventional-laminotomy group (p = 0.01 and 0.0002, respectively). The rate of change of paraspinal muscle fat infiltration was significantly lower in the split-laminotomy group than in the conventional-laminotomy group (p = 0.007). The incidence of complications was not significantly different between groups (p = 0.08). CONCLUSIONS This study was of the largest series reported thus far of pediatric patients who underwent split laminotomy and the only controlled study that has involved children. The authors' results reinforce the short-term benefit of split laminotomy in minimizing acute postoperative pain and long-term benefits of decreasing muscle atrophy and fatty degeneration, which are known to be associated with the development of chronic pain and spinal instability. Additional efforts for assessing long-term effects in the development of chronic pain, spinal instability, and spinal deformity are still necessary.

Clival meningocele causing bilateral hearing loss in a child due to superficial siderosis of the central nervous system: case report

Superficial siderosis (SS) of the CNS is a rare and often unrecognized condition. Caused by hemosiderin deposition from chronic, repetitive hemorrhage in the subarachnoid space, it results in parenchymal damage in the subpial layers of the brain and spinal cord. T2-weighted MRI shows the characteristic hypointensity of hemosiderin deposition, classically occurring around the cerebellum, brainstem, and spinal cord. Patients present with progressive gait ataxia and sensorineural hearing impairment. Although there have been several studies, case reports, and review articles over the years, the clear pathophysiology of subarachnoid space hemorrhage remains to be elucidated. The proposed causes include prior intradural surgery, prior trauma, tumors, vascular abnormalities, nerve root avulsion, and dural abnormalities. Surgical repair of a dural defect associated with SS has been shown to be efficacious at preventing symptomatic progression. There have been several reports of dural defects within the spinal canal treated with surgery. Here, the authors present the first known case of a dural defect of the ventral skull base, namely a clival meningocele, presumed to be causing SS. In this case report, a 10-year-old girl with a history of head trauma at the age of 3 years was found to have a clival meningocele 3 years after her original trauma. On follow-up imaging, the patient was found to have radiographic growth of the meningocele along with evidence of SS of the CNS. The patient was treated conservatively until she began to have progressive hearing loss. It was presumed that the growing meningocele was the source of her SS. An endoscopic endonasal transclival approach with a multilayer dural reconstruction was performed to fix the dural defect and repair the meningocele in hopes of mitigating the progression of her symptoms. At her 12-month postoperative follow-up, she was doing well, with audiometry showing a slightly decreased hearing threshold in the left ear but improved speech discrimination bilaterally. Postoperative MRI showed a stable level of hemosiderin deposition and meningocele repair. Long-term follow-up will be necessary to evaluate for continued clinical stabilization or possible improvement.

Stereotactic laser ablation of amygdala and hippocampus using a Leksell stereotactic frame

Approximately one-third of patients with epilepsy are resistant to medical therapy, particularly in those with mesial temporal lobe epilepsy. While there are several surgical modalities, efforts have been focused on developing safer and minimally invasive techniques. In this video, the authors present the case of a 45-year-old woman with a 2-year history of refractory left mesial temporal lobe epilepsy who underwent MRI-guided laser ablation of amygdala and hippocampus. There were no perioperative complications. The video can be found here: https://youtu.be/XFHt2jTdE_4 .

Microsurgical techniques in temporal lobe epilepsy

Temporal lobe resection is the most prevalent epilepsy surgery procedure. However, there is no consensus on the best surgical approach to treat temporal lobe epilepsy. Complication rates are low and efficacy is very high regarding seizures after such procedures. However, there is still ample controversy regarding the best surgical approach to warrant maximum seizure control with minimal functional deficits. We describe the most frequently used microsurgical techniques for removal of both the lateral and mesial temporal lobe structures in the treatment of medically intractable temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (corticoamygdalohippocampectomy and selective amygdalohippocampectomy). The choice of surgical technique appears to remain a surgeon's preference for the near future. Meticulous surgical technique and thorough three-dimensional microsurgical knowledge are essentials for obtaining the best results.

Recurrent giant cranial desmoid tumor in a 3-year-old boy with familial adenomatous polyposis requiring bifrontoparietal cranioplasty: case report

Desmoid tumors, also known as aggressive fibromatosis, are locally infiltrating musculoaponeurotic neoplasms arising in connective tissues. Desmoid tumors may be associated with familial adenomatous polyposis (FAP), a genetic disorder that presents with hundreds to thousands of precancerous colorectal polyps. The authors report the case of an 18-month-old boy who underwent resection of a right temporal desmoid tumor (initially diagnosed as cranial fasciitis) and developed a bilateral frontoparietal calvarial desmoid tumor 2 years later. The patient underwent gross-total resection of the tumor that required a large cranioplasty. He was subsequently diagnosed with FAP. The patient has been without tumor recurrence for 9 years afterwards and has not required revision of his cranioplasty. This is the first report describing a recurrent cranial desmoid tumor in a pediatric patient with FAP. The authors believe, however, that some of the cases previously reported as cranial fasciitis are likely desmoid tumors pathobiologically and genetically.

En bloc resection of a C-1 lateral mass osteosarcoma: technical note

Osteosarcoma is an aggressive primary bone tumor. It is currently treated with multimodality therapy including en bloc resection, which has been demonstrated to confer a survival benefit over intralesional resection. The authors present the case of an 8-year-old girl with a C-1 lateral mass osteosarcoma, which was treated with a 4-stage en bloc resection and spinal reconstruction. While technically complex, the feasibility of en bloc resection for spinal osteosarcoma should be explored in the pediatric population.

Long-term growth and alignment after occipitocervical and atlantoaxial fusion with rigid internal fixation in young children

OBJECT The long-term consequences of atlantoaxial (AA) and occipitocervical (OC) fusion and instrumentation in young children are unknown. Anecdotal reports have raised concerns regarding altered growth and alignment of the cervical spine after surgical intervention. The purpose of this study was to determine the long-term effects of these surgeries on the growth and alignment of the maturing spine. METHODS A multiinstitutional retrospective chart review was conducted for patients less than or equal to 6 years of age who underwent OC or AA fusion with rigid instrumentation at 9 participating centers. All patients had at least 3 years of clinical and radiographic follow-up data and radiographically confirmed fusion. Preoperative, immediate postoperative, and most recent follow-up radiographs and/or CT scans were evaluated to assess changes in spinal growth and alignment. RESULTS Forty children (9 who underwent AA fusion and 31 who underwent OC fusion) were included in the study (mean follow-up duration 56 months). The mean vertical growth over the fused levels in the AA fusion patients represented 30% of the growth of the cervical spine (range 10%-50%). Three different vertical growth patterns of the fusion construct developed among the 31 OC fusion patients during the follow-up period: 1) 16 patients had substantial growth (13%-46% of the total growth of the cervical spine); 2) 9 patients had no meaningful growth; and 3) 6 patients, most of whom presented with a distracted atlantooccipital dislocation, had a decrease in the height of the fused levels (range 7-23 mm). Regarding spinal alignment, 85% (34/40) of the patients had good alignment at follow-up, with straight or mildly lordotic cervical curvatures. In 1 AA fusion patient (11%) and 5 OC fusion patients (16%), we observed new hyperlordosis (range 43°-62°). There were no cases of new kyphosis or swan-neck deformity, evidence of subaxial instability, or unintended subaxial fusion. No preoperative predictors of these growth patterns or alignment were evident. CONCLUSIONS These results demonstrate that most young children undergoing AA and OC fusion with rigid internal fixation continue to have good cervical alignment and continued growth within the fused levels during a prolonged follow-up period. However, some variability in vertical growth and alignment exists, highlighting the need to continue close long-term follow-up.

Photodynamic therapy (PDT) for malignant brain tumors--where do we stand?

INTRODUCTION

What is the current status of photodynamic therapy (PDT) with regard to treating malignant brain tumors? Despite several decades of effort, PDT has yet to achieve standard of care.

PURPOSE

The questions we wish to answer are: where are we clinically with PDT, why is it not standard of care, and what is being done in clinical trials to get us there.

METHOD

Rather than a meta-analysis or comprehensive review, our review focuses on who the major research groups are, what their approaches to the problem are, and how their results compare to standard of care. Secondary questions include what the effective depth of light penetration is, and how deep can we expect to kill tumor cells.

CURRENT RESULTS

A measurable degree of necrosis is seen to a depth of about 5mm. Cavitary PDT with hematoporphyrin derivative (HpD) results are encouraging, but need an adequate Phase III trial. Talaporfin with cavitary light application appears promising, although only a small case series has been reported. Foscan for fluorescence guided resection (FGR) plus intraoperative cavitary PDT results were improved over controls, but are poor compared to other groups. 5-Aminolevulinic acid-FGR plus postop cavitary HpD PDT show improvement over controls, but the comparison to standard of care is still poor.

CONCLUSION

Continued research in PDT will determine whether the advances shown will mitigate morbidity and mortality, but certainly the potential for this modality to revolutionize the treatment of brain tumors remains. The various uses for PDT in clinical practice should be pursued.

Fifty consecutive hemispherectomies: outcomes, evolution of technique, complications, and lessons learned

BACKGROUND

Techniques for achieving hemispheric disconnection in patients with epilepsy continue to evolve.

OBJECTIVE

To review the outcomes of the first 50 hemispherectomy surgeries performed by a single surgeon with an emphasis on outcomes, complications, and how these results led to changes in practice.

METHODS

The first 50 hemispherectomy cases performed by the lead author were identified from a prospectively maintained database. Patient demographics, surgical details, clinical outcomes, and complications were critically reviewed.

RESULTS

From 2004 to 2012, 50 patients underwent hemispherectomy surgery (mean follow-up time, 3.5 years). Modified lateral hemispherotomy became the preferred technique and was performed on 44 patients. Forty patients (80%) achieved complete seizure freedom (Engel I). Presurgical and postsurgical neuropsychological evaluations demonstrated cognitive stability. Two cases were performed for palliation only. Previous hemispherectomy surgery was associated with worsened seizure outcome (2 of 6 seizure free; P .005). The use of Avitene was associated with a higher incidence of postoperative hydrocephalus (56% vs 18%; P = .03). In modified lateral hemispherotomy patients without the use of Avitene, the incidence of hydrocephalus was 13%. Complications included infection (n = 3), incomplete disconnection requiring reoperation (n = 1), reversible ischemic neurological deficit (n = 1), and craniosynostosis (n = 1). There were no (unanticipated) permanent neurological deficits or deaths. Minor technique modifications were made in response to specific complications.

CONCLUSION

The modified lateral hemispherotomy is effective and safe for both initial and revision hemispherectomy surgery. Avitene use appears to result in a greater incidence of postoperative hydrocephalus.

Subdural hematoma--a rare complication of removal of osseointegrated auricular prosthesis retention system

Periauricular osseointegrated prosthesis retention systems have been proven safe and effective in the management of microtia. Intracranial hemorrhage has been previously reported with implantation but is rare. We report a case of subdural hemorrhage following removal of an auricular prosthesis implant system. This case highlights the role of imaging, surgical technique, and neurosurgical support in prevention and management of intracranial hemorrhage associated with osseointegrated device removal.

Fibrin sealant to prevent subdural electrode migration during intracranial electroencephalographic monitoring in a patient with a large arachnoid cyst

Ensuring a stable position of intracranial electrode grids with good proximity to the cortical surface can be a technical challenge in patients with complex anomalous cerebral anatomy. This report illustrates the use of fibrin sealant to secure subdural electrodes to concave cortical surfaces during intracranial electroencephalographic monitoring for localization-related medically intractable epilepsy in a patient with a large arachnoid cyst.

Hemispherectomy in the treatment of seizures: a review

The term hemispherectomy refers to the complete removal or functional disconnection of a cerebral hemisphere. The technique was initially developed over 85 years ago to treat infiltrating brain tumors but is now used exclusively for medically refractory epilepsy. Hemispherectomy surgery has progressed from an extremely morbid procedure fraught with complications to a fairly routine one performed at most pediatric epilepsy centers with relatively low risk and great efficacy. The author reviews the history and evolution of hemispherectomy surgery, the relevant pathological conditions, as well as outcomes and complications.

Geometrical properties of the human child cervical spine with a focus on the C1 vertebra

OBJECTIVE

Child dummies and injury criteria used in automotive crashworthiness environments are based on scaling from the adult and/or between children of different ages. Cartilage-to-bone ossification, spinal canal and joint developments of the spine, and strength attainments do not grow linearly from birth to maturity. Though this is known to medical professionals, age-based quantitative analyses are needed to accurately model the pediatric spine. The objective of this study was to quantify longitudinal growths of various regions of the first cervical vertebrae, responsible for transmitting the axial load from the base of the skull through the condyles to the neck/torso.

METHODS

Computed tomography (CT) images of 54 children from one day to 18 years of age were retrospectively used to determine the following geometrical properties: bilateral neurocentral synchondroses widths, the width of posterior synchondrosis, outer and inner anteroposterior and transverse diameters, spinal canal area, and depths of the anterior and posterior arches of the C1 vertebra. Both axial and sagittal CT images were used in the analysis. Sagittal images were used to quantify data for the anterior and posterior arches and axial images were used for all described cross-sectional parameters.

RESULTS

Geometrical properties were extracted and reported for the various parameters at 6 months; one year; 18 months; and 3, 6, and 10 years of age corresponding to the dummy family ages routinely used in motor vehicle crashworthiness research and other applications. The outer transverse diameter ranged from 4.97 to 7.08 cm; outer and inner antero-posterior diameters ranged from 2.99 to 4.18 and 2.19 to 3.03 mm; and spinal canal area ranged from 4.34 to 6.68 mm(2). Other data are given in the body of the article. The growths of the first cervical vertebra quantified in terms of the above variables occurred nonlinearly with age and the degree of nonlinearity depended on the type of the geometrical parameter. Growths did not match with the simple scaling ratios based on the adult spine, used in different studies reported in the current literature.

CONCLUSIONS

These early nonlinear and nonuniform age- and local geometry-specific variations should be considered in human finite element models for an accurate transfer of the external load from the atlas to the subaxial spine and to improve their fidelity and biomechanical capabilities.

Incidence and outcome of pediatric patients with intracranial hemorrhage while supported on ventricular assist devices

Pediatric patients supported on ventricular assist devices (VADs) require systemic anticoagulation and are at risk for intracranial hemorrhage (ICH). Little is known about the incidence or outcomes of pediatric patients with ICH while supported on a VAD. A retrospective chart review of all patients receiving VAD support was completed. Patients diagnosed with ICH while supported on a VAD were identified. Significant factors prior to diagnosis of ICH, medical/surgical treatment of ICH, and patient outcomes were assessed. Five of 30 (17%) patients supported on a VAD from January 2000 to November 2012 were diagnosed with an ICH. Four patients had an identified cerebral thromboembolic injury prior to the ICH. Four patients required interruption in their anticoagulation regimen due to other bleeding concerns prior to ICH. Neurosurgical intervention consisted of evacuation of hemorrhage in one, whereas two others required management of hydrocephalus with external ventricular drainage. Three of the five patients died on VAD support. Two deaths were directly related to ICH, whereas the third was unrelated. Two patients were successfully transplanted; one remains with a significant neurological impairment, and the other has recovered with minimal residual impairment following neurosurgical evacuation of a large subdural hematoma. ICH is a devastating complication of VAD support. Prior ischemic infarcts and interruptions to anticoagulation may put a patient at risk for ICH. Prompt neurosurgical evaluation/intervention can result in positive outcomes.

Outcomes of cranioplasty following decompressive craniectomy in the pediatric population

Cranioplasty is routinely performed following decompressive craniectomy in both adult and pediatric populations. In adults, this procedure is associated with higher rates of complications than is elective cranial surgery. This study is a review of the literature describing risk factors for complications after cranioplasty surgery in pediatric patients. A systematic search of PubMed, Cochrane, and SCOPUS databases was undertaken. Articles were selected based on their titles and abstracts. Only studies that focused on a pediatric population were included; case reports were excluded. Studies in which the authors assessed bone flap storage method, timing of cranioplasty, material used (synthetic vs autogenous), skull defect size, and/or complication rates (bone resorption and surgical site infection) were selected for further analysis. Eleven studies that included a total of 441 cranioplasties performed in the pediatric population are included in this review. The findings are as follows: 1) Based on analysis of pooled data, using cryopreserved bone flaps during cranioplasty may lead to a higher rate of bone resorption and lower rate of infection than using bone flaps stored at room temperature. 2) In 3 of 4 articles describing the effect of time between craniectomy and cranioplasty on complication rate, the authors found no significant effect, while in 1 the authors found that the incidence of bone resorption was significantly lower in children who had undergone early cranioplasty. Pooling of data was not possible for this analysis. 3) There are insufficient data to assess the effect of cranioplasty material on complication rate when considering only cranioplasties performed to repair decompressive craniectomy defects. However, when considering cranioplasties performed for any indication, those in which freshly harvested autograft is used may have a lower rate of resorption than those in which stored autograft is used. 4) There is no appreciable effect of craniectomy defect size or patient age on complication rate. There is a paucity of articles describing outcomes and complications following cranioplasty in children and adolescents. However, based on the studies examined in this systematic review, there are reasons to suspect that method of flap preservation, timing of surgery, and material used may be significant. Larger prospective and retrospective studies are needed to shed more light on this important issue.

Posthemispherectomy hydrocephalus: results of a comprehensive, multiinstitutional review

PURPOSE

Hemispherectomy surgery for medically intractable epilepsy is known to cause hydrocephalus in a subset of patients. Existing data regarding the incidence of, and risk factors for, developing posthemispherectomy hydrocephalus have been limited by the relatively small number of cases performed by any single center. Our goal was to better understand this phenomenon and to identify risk factors that may predispose patients to developing hydrocephalus after hemispherectomy surgery.

METHODS

Fifteen pediatric epilepsy centers participated in this study. A retrospective chart review was performed on all available patients who had hemispherectomy surgery. Data collected included surgical techniques, etiology of seizures, prior brain surgery, symptoms and signs of hydrocephalus, timing of shunt placement, and basic demographics.

KEY FINDINGS

Data were collected from 736 patients who underwent hemispherectomy surgery between 1986 and 2011. Forty-six patients had preexisting shunted hydrocephalus and were excluded from analysis, yielding 690 patients for this study. One hundred sixty-two patients (23%) required hydrocephalus treatment. The timing of hydrocephalus ranged from the immediate postoperative period to 8.5 years after surgery, with 43 patients (27%) receiving shunts >90 days after surgery. Multivariate regression analysis revealed anatomic hemispherectomies (odds ratio [OR] 4.1, p < 0.0001) and previous brain surgery (OR 1.7, p = 0.04) as independent significant risk factors for developing hydrocephalus. There was a trend toward significance for the use of hemostatic agents (OR 2.2, p = 0.07) and the involvement of basal ganglia or thalamus in the resection (OR 2.2, p = 0.08) as risk factors.

SIGNIFICANCE

Hydrocephalus is a common sequela of hemispherectomy surgery. Surgical technique and prior brain surgery influence the occurrence of posthemispherectomy hydrocephalus. A significant portion of patients develop hydrocephalus on a delayed basis, indicating the need for long-term surveillance.

Rhythmic intrinsic bursting neurons in human neocortex obtained from pediatric patients with epilepsy

Neocortical oscillations result from synchronized activity of a synaptically coupled network and can be strongly influenced by the intrinsic firing properties of individual neurons. As such, the intrinsic electroresponsive properties of individual neurons may have important implications for overall network function. Rhythmic intrinsic bursting (rIB) neurons are of particular interest, as they are poised to initiate and/or strongly influence network oscillations. Although neocortical rIB neurons have been recognized in multiple species, the current study is the first to identify and characterize rIB neurons in the human neocortex. Using whole-cell current-clamp recordings, rIB neurons (n = 12) are identified in human neocortical tissue resected from pediatric patients with intractable epilepsy. In contrast to human regular spiking neurons (n = 12), human rIB neurons exhibit rhythmic bursts of action potentials at frequencies of 0.1-4 Hz. These bursts persist after blockade of fast excitatory neurotransmission and voltage-gated calcium channels. However, bursting is eliminated by subsequent application of the persistent sodium current (I(NaP)) blocker, riluzole. In the presence of riluzole (either 10 or 20 μm), human rIB neurons no longer burst, but fire tonically like regular spiking neurons. These data demonstrate that I(NaP) plays a critical role in intrinsic oscillatory activity observed in rIB neurons in the human neocortex. It is hypothesized that aberrant changes in I(NaP) expression and/or function may ultimately contribute to neurological diseases that are linked to abnormal network activity, such as epilepsy.

Craniosynostosis following hemispherectomy in a 2.5-month-old boy with intractable epilepsy

The authors report on the case of a 6-week-old boy who presented with infantile spasms. At 2.5 months of age, the patient underwent a right hemispherectomy. Approximately 3 months postoperatively, the patient presented with left coronal craniosynostosis. Subsequent cranial vault remodeling resulted in satisfactory cosmesis. Four years after surgery, the patient remains seizure free without the need for anticonvulsant medications. The authors believe this to be the first reported case of iatrogenic craniosynostosis due to hemispherectomy, and they describe 2 potential mechanisms for its development. This case suggests that, in the surgical treatment of infants with intractable epilepsy, minimization of brain volume loss through disconnection techniques should be considered, among other factors, when determining the best course of action.

Minicraniotomy versus bur holes for evacuation of chronic subdural collections in infants-a preliminary single-institution experience

OBJECT

Various surgical interventions have been described to evacuate chronic subdural collections (CSCs) of infancy. These include transfontanel percutaneous aspiration, subdural drains, placement of bur hole(s) with or without a subdural drain, and shunting. Shunt placement typically provides good long-term success (resolution of the subdural fluid), but comes with well-known early and late complications. Recently, the authors have used a mini-osteoplastic craniotomy technique with the goal of definitively treating these children with a single surgery while avoiding the many issues associated with a shunt. They describe their procedure and compare it with the traditional bur hole technique.

METHODS

In this single-institution retrospective study, the authors evaluated 26 cases involving patients who underwent treatment for CSC. Preoperative, intraoperative, and postoperative data were reviewed, including radiographic findings (density of the subdural fluid and ventricular and subarachnoid space size), neurological examination findings, and intraoperative fluid description. The primary outcome was treatment failure, defined as the patient requiring any subsequent surgical intervention after the index procedure (minicraniotomy or bur hole placement).

RESULTS

Fifteen patients (10 male and 5 female; median age 5.1 months) collectively underwent 27 minicraniotomy procedures (each procedure representing a hemisphere that was treated). In the bur hole group, there were 11 patients (6 male and 5 female; median age 4.6 months) with 18 hemispheres treated. Both groups had subdural drains placed. The average follow-up for each treatment group was just over 7 months. Treatment failure occurred in 2 patients (13%) in the minicraniotomy group compared with 5 patients (45%) in the bur hole group (p = 0.09). Furthermore, the 2 patients who had treatment failure in the minicraniotomy group required 1 subsequent surgery each, whereas the 5 in the bur hole group needed a total of 9 subsequent surgeries. Eventually, 80% of the patients in the minicraniotomy group and 70% of those in the bur hole group had resolution of the subdural collections on the last imaging study.

CONCLUSIONS

The minicraniotomy technique may be a superior technique for the treatment of CSCs in infants compared with bur hole evacuation. The minicraniotomy provides greater visualization of the subdural space and allows more aggressive evacuation of the fluid, better irrigation of the space, the ability to fenestrate any accessible membranes safely, and continued egress of fluid into the subgaleal space. Although this preliminary report has obvious limitations, evaluation of this technique may be worthy of a prospective, multiinstitutional collaborative effort.

Moyamoya disease in early infancy: case report and literature review

Moyamoya disease is a progressive, occlusive, cerebrovascular arteriopathy, characterized by bilateral stenosis of the distal internal carotid arteries or branches, with the development of compensatory collateral vessels. It is infrequently reported during infancy. We describe a 2-month-old boy presenting with stroke secondary to moyamoya disease, successfully treated with revascularization surgery at age 3 months. To our knowledge, this report represents the youngest such patient. This case and a review of the literature regarding moyamoya disease during infancy suggest that these patients are at significant risk for further ischemic events and respond well to prompt revascularization surgery.

3D visualization of subdural electrode shift as measured at craniotomy reopening

PURPOSE

Subdural electrodes are implanted for recording intracranial EEG (iEEG) in cases of medically refractory epilepsy as a means to locate cortical regions of seizure onset amenable to surgical resection. Without the aid of imaging-derived 3D electrode models for surgical planning, surgeons have relied on electrodes remaining stationary from the time between placement and follow-up resection. This study quantifies electrode shift with respect to the cortical surface occurring between electrode placement and subsequent reopening.

METHODS

CT and structural MRI data were gathered following electrode placement on 10 patients undergoing surgical epilepsy treatment. MRI data were used to create patient specific post-grid 3D reconstructions of cortex, while CT data were co-registered to the MRI and thresholded to reveal electrodes only. At the time of resective surgery, the craniotomy was reopened and electrode positions were determined using intraoperative navigational equipment. Changes in position were then calculated between CT coordinates and intraoperative electrode coordinates.

RESULTS

Five out of ten patients showed statistically significant overall magnitude differences in electrode positions (mean: 7.2mm), while 4 exhibited significant decompression based shift (mean: 4.7mm), and 3 showed significant shear displacement along the surface of the brain (mean: 7.1mm).

DISCUSSION

Shift in electrode position with respect to the cortical surface has never been precisely measured. We show that in 50% of our cases statistically significant shift occurred. These observations demonstrate the potential utility of complimenting electrode position measures at the reopening of the craniotomy with 3D electrode and brain surface models derived from post-implantation CT and MR imaging for better definition of surgical boundaries.

Corpus callosotomy in multistage epilepsy surgery in the pediatric population

OBJECT

The object of this study was to evaluate surgical outcome in a select group of patients with medically refractory epilepsy who had undergone corpus callosotomy combined with bilateral subdural electroencephalography (EEG) electrode placement as the initial step in multistage epilepsy surgery.

METHODS

A retrospective chart review of 18 children (ages 3.5-18 years) with medically refractory symptomatic generalized or localization-related epilepsy was undertaken. A corpus callosotomy with subdural bihemispheric EEG electrode placement was performed as the initial step in multistage epilepsy surgery. All of the patients had tonic and atonic seizures; 6 patients also experienced complex partial seizures. All of the patients had frequent generalized epileptiform discharges as well as multifocal independent epileptiform discharges on surface EEG monitoring. Most of the patients (94%) had either normal (44%) MR imaging studies of the brain or bihemispheric abnormalities (50%). One patient had a suspected unilateral lesion (prominent sylvian fissure).

RESULTS

Of the 18 patients who underwent corpus callosotomy and placement of subdural strips and grids, 12 progressed to further resection based on localizing data obtained during invasive EEG monitoring. The mean patient age was 10.9 years. The duration of invasive monitoring ranged from 3 to 14 days, and the follow-up ranged from 6 to 70 months (mean 35 months). Six (50%) of the 12 patients who had undergone resection had an excellent outcome (Engel Class I or II). There were no permanent neurological deficits or deaths.

CONCLUSIONS

The addition of invasive monitoring for patients undergoing corpus callosotomy for medically refractory epilepsy may lead to the localization of surgically amenable seizure foci, targeted resections, and improved seizure outcomes in a select group of patients typically believed to be candidates for palliative surgery alone.

Quantitative analyses of pediatric cervical spine ossification patterns using computed tomography

The objective of the present study was to quantify ossification processes of the human pediatric cervical spine. Computed tomography images were obtained from a high resolution scanner according to clinical protocols. Bone window images were used to identify the presence of the primary synchondroses of the atlas, axis, and C3 vertebrae in 101 children. Principles of logistic regression were used to determine probability distributions as a function of subject age for each synchondrosis for each vertebra. The mean and 95% upper and 95% lower confidence intervals are given for each dataset delineating probability curves. Posterior ossifications preceded bilateral anterior closures of the synchondroses in all vertebrae. However, ossifications occurred at different ages. Logistic regression results for closures of different synchondrosis indicated p-values of <0.001 for the atlas, ranging from 0.002 to <0.001 for the axis, and 0.021 to 0.005 for the C3 vertebra. Fifty percent probability of three, two, and one synchondroses occurred at 2.53, 6.97, and 7.57 years of age for the atlas; 3.59, 4.74, and 5.7 years of age for the axis; and 1.28, 2.22, and 3.17 years of age for the third cervical vertebrae, respectively. Ossifications occurring at different ages indicate non-uniform maturations of bone growth/strength. They provide an anatomical rationale to reexamine dummies, scaling processes, and injury metrics for improved understanding of pediatric neck injuries.

Giant posterior fossa cavernous malformations in 2 infants with familial cerebral cavernomatosis: the case for early screening

The author reports the details in 2 cases of infants with familial cerebral cavernomatosis who presented in dire condition from hemorrhagic posterior fossa cavernous malformations. In Case 1, a 4-month-old boy presented with opisthotonos, gaze palsy, and lethargy. Magnetic resonance imaging revealed a multilobulated cavernous malformation in the fourth ventricle with evidence of bleeding and obstructive hydrocephalus. In Case 2, a 7-month-old girl presented with lethargy, followed by rapid neurological decline. Imaging demonstrated a large lesion involving both the brainstem and cerebellum, with obstructive hydrocephalus. Both patients required immediate surgical intervention, and external ventricular drainage and posterior fossa craniotomies were performed. Both patients made excellent recoveries. These cases suggest that infants in families with suspected or confirmed familial cerebral cavernomatosis should be screened at an early age.

Spinal dural closure with nonpenetrating titanium clips in pediatric neurosurgery

OBJECT

The authors report a retrospective review of their experience using nonpenetrating titanium anastomotic clips for dural closure in 27 pediatric cases (26 patients) of spinal surgery for a variety of diagnoses. The goal of this review was to define the utility of these clips in pediatric neurosurgical spinal procedures, identify complications of their use, and assess the effects on postoperative imaging because of their use.

METHODS

Institutional review board approval was obtained for a retrospective chart review of all patients in whom titanium dural clips had been utilized. Patients were identified over a 2-year period using hospital and clinic records, and data were collected on the patient demographics, surgical diagnosis and procedure, durotomy location and length, and adjunctive closure methods. Postoperative complications were assessed. When available, postoperative imaging data were reviewed.

RESULTS

Twenty-six patients underwent 27 operations over a 20-month period. They ranged in age from 2.5 months to 18.5 years, with a median age of 3.2 years and an average age of 5.8 years. The operative diagnosis was some form of spinal dysraphism in 19 patients, with a syrinx or dural tear in 2 patients each, and an arachnoid cyst in 3 cases; 1 patient had a tumor resected. Operative levels included lumbosacral (19), thoracic (7), and cervical (1). Dural exposure was limited to 1 laminar level in 16 cases, 2 levels in 8, and 3 levels in 1; 2 cases involved focal dural tears. A combination of additional hemostatic and tissue sealant materials was applied over the clips in 16 cases. One patient required reoperation 13 months after clip placement. Prior clip use did not make subsequent exposure and opening more complicated. No significant complications were identified in the follow-up period ranging from 1 to 24 months. There were no documented CSF leaks. The clips are not easily seen on plain radiographs and did not cause artifacts or distortion on either CT or MR imaging.

CONCLUSIONS

Nonpenetrating titanium anastomotic clips afford an effective means of closure while limiting the exposure needed, and thus allowing more minimally invasive approaches. In tight spaces, dural closure is accomplished more easily and faster with the clips as compared with conventional suturing. No significant complications were seen from clip use, and the clips did not interfere with postoperative imaging.