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Journal: Journal of neurosurgery. Pediatrics

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Object Bicycle accidents are a very important cause of clinically important traumatic brain injury (TBI) in children. One factor that has been shown to mitigate the severity of lesions associated with TBI in such scenarios is the proper use of a helmet. The object of this study was to test and evaluate the protection afforded by a children’s bicycle helmet to human cadaver skulls with a child’s anthropometry in both “impact” and “crushing” situations. Methods The authors tested human skulls with and without bicycle helmets in drop tests in a monorail-guided free-fall impact apparatus from heights of 6 to 48 in onto a flat steel anvil. Unhelmeted skulls were dropped at 6 in, with progressive height increases until failure (fracture). The maximum resultant acceleration rates experienced by helmeted and unhelmeted skulls on impact were recorded by an accelerometer attached to the skulls. In addition, compressive forces were applied to both helmeted and unhelmeted skulls in progressive amounts. The tolerance in each circumstance was recorded and compared between the two groups. Results Helmets conferred up to an 87% reduction in so-called mean maximum resultant acceleration over unhelmeted skulls. In compression testing, helmeted skulls were unable to be crushed in the compression fixture up to 470 pound-force (approximately 230 kgf), whereas both skull and helmet alone failed in testing. Conclusions Children’s bicycle helmets provide measurable protection in terms of attenuating the acceleration experienced by a skull on the introduction of an impact force. Moreover, such helmets have the durability to mitigate the effects of a more rare but catastrophic direct compressive force. Therefore, the use of bicycle helmets is an important preventive tool to reduce the incidence of severe associated TBI in children as well as to minimize the morbidity of its neurological consequences.

Concepts: Brain, Traumatic brain injury, Compressive stress, Bicycle, Motorcycle helmet, Helmet, Bicycle helmet, Helmets

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OBJECTIVE Although 70% of football players in the United States are youth players (6-14 years old), most research on head impacts in football has focused on high school, collegiate, or professional populations. The objective of this study was to identify the specific activities associated with high-magnitude (acceleration > 40g) head impacts in youth football practices. METHODS A total of 34 players (mean age 9.9 ± 0.6 years) on 2 youth teams were equipped with helmet-mounted accelerometer arrays that recorded head accelerations associated with impacts in practices and games. Videos of practices and games were used to verify all head impacts and identify specific drills associated with each head impact. RESULTS A total of 6813 impacts were recorded, of which 408 had accelerations exceeding 40g (6.0%). For each type of practice drill, impact rates were computed that accounted for the length of time that teams spent on each drill. The tackling drill King of the Circle had the highest impact rate (95% CI 25.6-68.3 impacts/hr). Impact rates for tackling drills (those conducted without a blocker [95% CI 14.7-21.9 impacts/hr] and those with a blocker [95% CI 10.5-23.1 impacts/hr]) did not differ from game impact rates (95% CI 14.2-21.6 impacts/hr). Tackling drills were observed to have a greater proportion (between 40% and 50%) of impacts exceeding 60g than games (25%). The teams in this study participated in tackling or blocking drills for only 22% of their overall practice times, but these drills were responsible for 86% of all practice impacts exceeding 40g. CONCLUSIONS In youth football, high-magnitude impacts occur more often in practices than games, and some practice drills are associated with higher impact rates and accelerations than others. To mitigate high-magnitude head impact exposure in youth football, practices should be modified to decrease the time spent in drills with high impact rates, potentially eliminating a drill such as King of the Circle altogether.

Concepts: United States, Shock, Drill, Circle, Acceleration, Impact factor, American football, Specific force

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OBJECTIVE Recent advances in optics and miniaturization have enabled the development of a growing number of minimally invasive procedures, yet innovative training methods for the use of these techniques remain lacking. Conventional teaching models, including cadavers and physical trainers as well as virtual reality platforms, are often expensive and ineffective. Newly developed 3D printing technologies can recreate patient-specific anatomy, but the stiffness of the materials limits fidelity to real-life surgical situations. Hollywood special effects techniques can create ultrarealistic features, including lifelike tactile properties, to enhance accuracy and effectiveness of the surgical models. The authors created a highly realistic model of a pediatric patient with hydrocephalus via a unique combination of 3D printing and special effects techniques and validated the use of this model in training neurosurgery fellows and residents to perform endoscopic third ventriculostomy (ETV), an effective minimally invasive method increasingly used in treating hydrocephalus. METHODS A full-scale reproduction of the head of a 14-year-old adolescent patient with hydrocephalus, including external physical details and internal neuroanatomy, was developed via a unique collaboration of neurosurgeons, simulation engineers, and a group of special effects experts. The model contains “plug-and-play” replaceable components for repetitive practice. The appearance of the training model (face validity) and the reproducibility of the ETV training procedure (content validity) were assessed by neurosurgery fellows and residents of different experience levels based on a 14-item Likert-like questionnaire. The usefulness of the training model for evaluating the performance of the trainees at different levels of experience (construct validity) was measured by blinded observers using the Objective Structured Assessment of Technical Skills (OSATS) scale for the performance of ETV. RESULTS A combination of 3D printing technology and casting processes led to the creation of realistic surgical models that include high-fidelity reproductions of the anatomical features of hydrocephalus and allow for the performance of ETV for training purposes. The models reproduced the pulsations of the basilar artery, ventricles, and cerebrospinal fluid (CSF), thus simulating the experience of performing ETV on an actual patient. The results of the 14-item questionnaire showed limited variability among participants' scores, and the neurosurgery fellows and residents gave the models consistently high ratings for face and content validity. The mean score for the content validity questions (4.88) was higher than the mean score for face validity (4.69) (p = 0.03). On construct validity scores, the blinded observers rated performance of fellows significantly higher than that of residents, indicating that the model provided a means to distinguish between novice and expert surgical skills. CONCLUSIONS A plug-and-play lifelike ETV training model was developed through a combination of 3D printing and special effects techniques, providing both anatomical and haptic accuracy. Such simulators offer opportunities to accelerate the development of expertise with respect to new and novel procedures as well as iterate new surgical approaches and innovations, thus allowing novice neurosurgeons to gain valuable experience in surgical techniques without exposing patients to risk of harm.

Concepts: Surgery, Psychometrics, Validity, Cerebrospinal fluid, Neurosurgery, Hydrocephalus, Content validity, Special effects

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Object Ventriculoperitoneal (VP) shunt placement remains the mainstay treatment for pediatric hydrocephalus. These devices have a relatively high complication and failure rate, often requiring multiple revisions. The authors present a single institution’s experience of pediatric patients treated with VP shunts. With an average follow-up time of 20 years, this study is among the longest reports of VP shunt revision in the literature to date. Hydrocephalus origins, shunt revision rates, and causes of shunt failure are described. Patients who underwent their first shunt revision more than 10 years after initial shunt placement were also explored. Methods A retrospective chart review was performed on all pediatric patients who underwent VP shunt placement from January 1990 through November 1996 at the University of Rochester Medical Center. Only patients who had at least 15 years of follow-up since their initial shunting procedure were included. Results A total of 234 procedures were performed on 64 patients, with a mean follow-up of 19.9 years. Patients ranged from a few days to 17.2 years old when they received their original shunt, with a median age of 4 months; 84.5% of the patients required 1 or more shunt revisions and 4.7% required 10 or more. Congenital defects, Chiari Type II malformations, tumors, and intraventricular hemorrhage were the most common causes of hydrocephalus. Overall, patients averaged 2.66 revisions, with proximal (27%) and distal (15%) catheter occlusion, disconnection (11%), and infection (9%) comprising the most common reasons for shunt malfunction. Notably, 12.5% of patients did not require their first shunt revision until more than 10 years after initial device placement, a previously undescribed finding due to the short follow-up duration in previous studies. Conclusions This long-term retrospective analysis of pediatric VP shunt placement revealed a relatively high rate of complications with need for shunt revision as late as 17 years after initial placement. Catheter occlusion represented a significant percentage of shunt failures. Cerebrospinal fluid shunting has a propensity for mechanical failure and patients with VP shunts should receive follow-up through the transition to adulthood.

Concepts: Intracranial pressure, Cerebrospinal fluid, Failure, Congenital disorder, Hydrocephalus, Congenital disorders, Arnold-Chiari malformation, Cerebral shunt

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Object The association of Chiari malformation Type I (CM-I) with syndromic craniosynostosis (SC) in children is well established. Central sleep apnea (CSA) may subsequently occur. However, sleep studies performed in these patients have been focused mainly on assessing the severity of obstructive sleep apnea. Therefore, the incidence and management of CSA in these patients remains poorly defined. Authors of this study aimed to assess the efficacy of foramen magnum decompression (FMD) in resolving CSA, initially detected incidentally, in a small cohort of patients with CM-I and SC. Methods The clinical data for 5 children who underwent FMD for CSA at Alder Hey Children’s Hospital between December 2007 and December 2009 were retrospectively analyzed. Outcomes were evaluated with respect to FMDs by utilizing pre- and postdecompression sleep studies. Of the 5 patients, 2 had Crouzon syndrome and 3 had Pfeiffer syndrome. Results Patient age at the time of surgery ranged from 1.1 to 12.6 years (median 4.1 years). The median postoperative follow-up was 3.6 years. Sleep studies revealed that 2 children experienced a > 80% reduction in CSAs at 1.5 and 21 months after decompression. The remaining 3 children experienced a > 60% reduction in CSAs when reevaluated between 2 and 10 months after decompression. The associated central apnea index improved for all patients. Conclusions Findings suggested that FMD is an effective treatment modality for improving CSA in patients with SC and associated CM-I. The use of multimodal polysomnography technology may improve the evaluation and management of these patients.

Concepts: Sleep, Sleep disorder, Sleep apnea, Polysomnography, Obstructive sleep apnea, Sleep medicine, Arnold-Chiari malformation, Alder Hey Children's Hospital

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Object Previous studies of systemic and intralesional administration of nonpegylated interferon have shown efficacy against craniopharyngioma. Pegylaion of interferon-α-2b (PI) prolongs the half-life, allowing sustained exposure of the drug over time, and enhances efficacy. The authors report the results of the use of PI in 5 children with recurrent craniopharyngiomas. Methods Five children, ranging in age from 9 to 15 years, with recurrent craniopharyngiomas were treated for up to 2 years with subcutaneous injections of PI at a dose of 1-3 μg/kg/week. Tumor response was assessed using MRI. Results All patients had stable disease or better in response to PI. One patient experienced a recurrence after gross-total resection (GTR). She initially showed an increase in the predominantly cystic tumor after 3 months of treatment, followed by a complete response. She required no further intervention and remains without evidence of disease 10 years after starting treatment. Another patient experienced recurrence 3.3 years after subtotal resection (STR) and radiation therapy. He had complete disappearance of the predominantly cystic component after 4 months of treatment, and a small residual calcified mass remains 5 years later. The third patient experienced recurrence after 3 GTRs. He had a complete response after 7 months of treatment and remains without evidence of disease 19 months after starting treatment. The fourth patient experienced recurrence after 2 STRs. He had a 30% decrease in tumor size after 4 months of treatment, which was maintained for 12 months at which point the cyst began to increase in size. The final patient experienced recurrence after GTR and has stable disease 6 months after starting treatment with PI. Conclusions The use of PI in children with recurrent craniopharyngiomas can result in significant and durable responses and potentially delay or avoid the need for radiation therapy.

Concepts: Electron, Medicine, Cancer, Radiation therapy, Cyst, Recurrence relation, Subcutaneous injection, Craniopharyngioma

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Object After untethering of spinal dysraphism, some patients present with neurological deterioration, defined as retethered cord syndrome. It is known that surgical untethering is an option for improving the symptoms of retethered cord syndrome. Previous reports have shown that postoperative improvement in retethered cord syndrome was noted in the majority of patients presenting with pain, and in more patients with motor weakness than in those with urological symptoms. The authors speculate that subjective symptoms may be detected while symptoms are still reversible. In contrast, changes in urological function are less easy to diagnose, and delays in treatment may be complicated by advanced symptoms. In this study, patients with retethered cord syndrome were evaluated to investigate the benefits of performing routine urodynamic study to detect detrusor overactivity, which is considered to be a subclinical change of urological function, and to investigate the efficacy of early untethering surgery on the symptoms of retethered cord syndrome. Methods Surgical indications and outcomes of 78 untethering operations (20 for myelomeningocele, 58 for spinal lipoma) for retethered cord syndrome were examined. Diagnosis of retethered cord syndrome was defined by a multidisciplinary spina bifida team, and included routine urodynamic study. Results Preoperative symptoms included urological symptoms (70%), lower-extremity symptoms (45%), and others. The most frequent urological symptom was detrusor overactivity detected by urodynamic study (88.7%). Urinary incontinence was only found in 9.4% of patients. Postoperatively, progressive motor weakness improved in all patients, and sensory symptoms improved in 94%. Urological symptoms improved in 80% of the patients with urinary incontinence and in 75% of the patients with detrusor overactivity. Postoperative urodynamic study showed a significant increase in bladder volume (p < 0.05). The most common complication was temporary lower leg paresthesia that recovered at follow-up. Aggravated dysuria was noted in 3 patients. Conclusions Early untethering operations offer symptomatic relief to patients with retethered cord syndrome. Urodynamic study findings, especially detrusor overactivity, are considered to be the most significant indicators for early diagnosis of retethered cord syndrome.

Concepts: Better, Medical terms, Urinary incontinence, Symptoms, Urinary bladder, Spina bifida

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Headache occurs after dural puncture in about 1%-25% of children who undergo the procedure-a rate similar to that seen in adults. Persistence of post-dural puncture headache in spite of bed rest, increased fluid intake, and epidural blood patch treatment, however, is rare. The authors reviewed the medical records and imaging studies of all patients 19 years of age or younger who they evaluated between 2001 and 2010 for intracranial hypotension, and they identified 8 children who had persistent post-dural puncture headache despite maximal medical treatment and placement of epidural blood patches. A CSF leak could be demonstrated radiologically and treated surgically in 3 of these patients, and the authors report these 3 cases. The patients were 2 girls (ages 14 and 16 years) who had undergone lumbar puncture for evaluation of headache and fever and 1 boy (age 13 years) who had undergone placement of a lumboperitoneal shunt using a Tuohy needle for treatment of pseudotumor cerebri. The boy also had undergone a laminectomy and exploration of the posterior dural sac, but no CSF leak could be identified. All 3 patients presented with new-onset orthostatic headaches, and in all 3 cases MRI demonstrated a large ventral lumbar or thoracolumbar CSF collection. Conventional myelography or digital subtraction myelography revealed a ventral dural defect at L2-3 requiring surgical repair. Through a posterior transdural approach, the dural defect was repaired using 6-0 Prolene sutures and a dural substitute. Postoperative recovery was uneventful, with complete resolution of orthostatic headache and of the ventral cerebrospinal fluid leak on MRI. The authors conclude that persistent postdural puncture headache requiring surgical repair is rare in children. They note that the CSF leak may be located ventrally and may require conventional or digital subtraction myelography for exact localization and that transdural repair is safe and effective in eliminating the headaches.

Concepts: Spinal cord, Intracranial pressure, Neurology, Cerebrospinal fluid, Lumbar puncture, Spontaneous cerebrospinal fluid leak, Post dural puncture headache, Epidural blood patch

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Dermoid cysts, encephaloceles, and dermal sinus tracts represent abnormalities that develop during the process of embryogenesis. The elucidation of the precise timing of formation for these malformations has remained elusive at the molecular level of study. Yet, clinical experience has demonstrated that these malformations do not all occur in the same patient, suggesting a shared pathway that goes awry at distinct points for different patients, resulting in 1 of the 3 malformations. Herein the authors describe a case in which all 3 malformations were present in a single patient. This is the first description in the English literature of a sincipital encephalocele occurring with a dermoid cyst and a dermal sinus tract.

Concepts: Patient, Literature, English language, Cyst, Dermoid cyst, Pilonidal cyst, English studies, Sinus

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Object There has been an increase in civilian gun violence since the late 1980s, with a disproportionately high increase occurring within the pediatric population. To date, no definite treatment paradigm exists for the management of these patients, nor is there a full understanding of the predictors of favorable clinical outcome in this population. Methods The authors completed a retrospective review of all victims of intracranial gunshot injury from birth to age 18 years at a major metropolitan Level 1 trauma center (n = 48) from 2002 to 2011. The predictive values of widely accepted adult clinical and radiographic factors for poor prognosis were investigated. Results Eight statistically significant factors (p < 0.05) for favorable outcome were identified. These factors include single hemispheric involvement, absence of a transventricular trajectory, < 3 lobes involved, ≥ 1 reactive pupil on arrival, systolic blood pressure > 100 mm Hg on arrival, absence of deep nuclei and/or third ventricular involvement, initial ICP < 30 mm Hg when monitored, and absence of midline shift. Of these 8 factors, 5 were strong predictors of favorable clinical outcome as defined by Glasgow Outcome Scale score of 4 or 5. These predictive factors included absence of a transventricular trajectory, < 3 lobes involved, ≥ 1 reactive pupil on arrival, absence of deep nuclei and/or third ventricular involvement, and initial ICP < 30 mm Hg. These findings form the basis of the St. Louis Scale for Pediatric Gunshot Wounds to the Head, a novel metric to inform treatment decisions for pediatric patients who sustain these devastating injuries. Conclusions The pediatric population tends to demonstrate more favorable outcomes following intracranial gunshot injury when compared with the adult population; therefore some patients may benefit from more aggressive treatment than is considered for adults. The St. Louis Scale for Pediatric Gunshot Wounds to the Head may provide critical data toward evidence-based guidelines for clinical decision making.

Concepts: Statistics, Blood pressure, Intracranial pressure, Medical emergencies, Injuries, Injury, Wound, Ballistic trauma