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Edward S. Ahn and Edward R. Smith

✓Infratentorial and spinal subdural hematomas (SDHs) from traumatic injury in the pediatric population occur with such rarity that they can present the clinician with a challenge in diagnosis and management. When such hematomas are correctly identified, clinicians must decide whether to evacuate the lesion or manage it expectantly. The authors discuss the case of a 4-year-old child who presented with a clival and spinal SDH after a fall from a fourth-story window. The clinical and radiographic findings support a possible mechanism of evolution of these lesions. There is little evidence to guide management of clival and spinal SDHs. This case supports the evaluation for a spinal SDH when a clival hematoma is diagnosed. In the setting of a good neurological examination, expectant management can be an appropriate method of treatment. Additionally, this case lends insight into the pathophysiology of spinal SDHs. Unlike its intracranial counterpart, the spinal subdural space lacks bridging veins. The mechanism of formation of spinal SDHs after trauma has been heretofore relatively unclear. The images in this case support the hypothesis that redistribution of the clival SDH to dependent areas in the spinal subdural space is a significant mechanism in the evolution of these lesions.

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Courtney Pendleton, Edward S. Ahn, and Alfredo Quiñones-Hinojosa


Harvey Cushing, credited with pioneering the field of neurosurgery as a distinct surgical subspecialty in the US, was at the forefront of neurooncology, publishing seminal papers on the diagnosis and treatment of pediatric brain tumors during the latter part of his career. However, his contributions to the surgical treatment of these lesions during the early stages of his tenure at the Johns Hopkins Hospital, from 1896 to 1912, remain largely unknown.


After obtaining institutional review board approval, and through the courtesy of the Alan Mason Chesney Archives, the authors reviewed the Johns Hopkins Hospital surgical files from the years 1896 to 1912. Patients younger than 18 years of age, presenting with symptoms suspicious for an intracranial tumor, and undergoing surgical intervention by Cushing were selected for further analysis.


Of the 40 pediatric patients undergoing surgery for suspected intracranial neoplasms, 26 were male. The mean age among the entire sample was 10.1 years. Cushing used three main operative approaches in the surgical treatment of pediatric intracranial neoplasms: infratentorial/suboccipital, subtemporal, and hemisphere flap. Twenty-three patients had negative findings following both the primary and subsequent surgical interventions conducted by Cushing. Postoperative conditions following the primary surgical intervention were improved in 24 patients. Twelve patients (30%) died during their inpatient stay for the primary intervention. The mean time to the last follow-up was 24.9 months; the mean time to death was 10.0 months.


Cushing strove to maximize exposure while minimizing blood loss in an attempt to increase his ability to successfully treat pediatric brain tumors. His early contributions to the field of pediatric neurooncology demonstrate his commitment to advancing the field of neurosurgery.

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Jonathan Pindrik, George I. Jallo, and Edward S. Ahn

This case series highlights multiple complications and subsequent removal of retained shunt hardware in pediatric patients after successful endoscopic third ventriculostomy (ETV). Removal or retention of existing shunt hardware following ETV represents an important dilemma. Prior studies have reported infections and organ perforation related to nonfunctioning shunts but none in the context of successful ETV. Data obtained in 3 children with hydrocephalus treated at the authors' institution were retrospectively reviewed after the patients experienced complications due to retained shunt hardware following ETV. Etiologies of hydrocephalus included tectal glioma and intraventricular hemorrhage. All 3 patients had a history of multiple shunt revisions and underwent urgent ETV in the setting of a shunt malfunction. In each case, the entire shunt system was left in situ, but it became the source of subsequent complications. Two of the 3 patients presented with the shunt infected by gram-negative bacilli 10 days and 4.5 months postoperatively, respectively. The remaining patient experienced wound dehiscence over the shunt valve 4.5 months after ETV. In all patients, the complications were managed successfully by removing the shunt hardware. None of the patients required repeat shunt insertion from the time of removal throughout the follow-up period (mean 24 months, range 9–36 months). During the study period, a total of 6 patients with indwelling shunt hardware underwent ETV with the expectation of being shunt independent. Among these 6 patients, 3 experienced no complications from the retained hardware whereas 3 patients (50%) ultimately experienced adverse consequences related to retained hardware. This case series illustrates complications involving retained shunt hardware after successful ETV. These examples support consideration of shunt removal at the time of ETV in the appropriate context.

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James L. Frazier, Edward S. Ahn, and George I. Jallo

✓ Brain abscesses occur infrequently but continue to be problematic for the pediatric neurosurgical community. The incidence of brain abscesses in children has not changed much, although individual reports may show an increase or decrease in the number of reported cases depending on the patient population studied. An increase could be attributed to earlier detection due to advancements in imaging modalities and/or to an increase in the number of children with immunodeficient states caused by AIDS, chemotherapy for malignant lesions, and immunosuppressive therapy for organ transplantation. A decrease in the incidence of brain abscesses could be attributed to practices such as antibiotic treatment for otitis media, sinusitis, and/or prophylactic antimicrobial treatment for congenital heart disease in children. The morbidity and mortality rates associated with brain abscesses have not changed dramatically in the antibiotic and imaging era, and their preferred management can vary among healthcare providers. These lesions have been successfully treated by neurosurgeons. The causes of brain abscesses are highly variable in children, which is also the case in adults, but the predisposing factors in the pediatric population differ in prevalence. Cyanotic congenital heart disease, hematogenous dissemination, contiguous infection, and penetrating traumatic injuries are the most common causes of brain abscesses in children. In this review, the authors discuss the causes and medical and surgical management of brain abscesses in children.

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Cody L. Nesvick, Soliman Oushy, David J. Daniels, and Edward S. Ahn


Postoperative pain can limit the recovery of children undergoing craniotomy for tumor resection, and pain management is highly variable between institutions and practitioners. Nonsteroidal antiinflammatory drugs (NSAIDs) are effective in treating postoperative pain following craniotomy, but their use has been limited by concerns about postoperative hemorrhage. The risk of postoperative hemorrhage is not insignificant in patients undergoing craniotomy for tumor resection. No study has specifically addressed the safety of NSAIDs in the immediate postoperative setting following craniotomy for tumor resection in pediatric patients.


The authors performed a retrospective cohort study in patients younger than 18 years of age who underwent craniotomy for tumor resection at a single tertiary referral center between 2009 and 2019. The study outcomes were 1) postoperative hemorrhage requiring return to the operating room for decompression, evacuation, or CSF diversion for hemorrhage-associated hydrocephalus; and 2) more-than-minimal hemorrhage on routine postoperative imaging. Patients receiving any NSAID in the hospital formulary on the same day as surgery (postoperative day zero [POD0]) were designated as such.


Two hundred seventy-six children underwent 308 craniotomies for tumor resection over the study period. One hundred fifty-four patients (50.0%) received at least one dose of an NSAID on POD0. Six patients (1.9%) required a return to the operating room for a hemorrhagic complication, including 3 who received an NSAID on POD0 (OR 1.00, 95% CI 0.20–5.03). Seventeen patients (6.3% of patients imaged) had more-than-minimal hemorrhage on routine postoperative imaging, 9 of whom received an NSAID on POD0 (OR 1.08, 95% CI 0.40–2.89).


Use of NSAIDs on POD0 was not associated with either an increased risk of hemorrhage requiring a return to the operating room or asymptomatic hemorrhage on routine postoperative imaging. The overall incidence of clinically significant postoperative intracranial hemorrhage is low. These data support the use of NSAIDs as a safe measure for pain control in the postoperative setting for children undergoing craniotomy for tumor resection.

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Edward S. Ahn and Archis R. Bhandarkar

The authors describe an endoscopic strip craniectomy through a single incision for the treatment of sagittal craniosynostosis in a young infant. The endoscopic strip craniectomy was first introduced with the use of two incisions on either end of the fused suture. This single-incision technique offers several advantages. There is a cosmetic advantage and a reduced risk of wound complications. This technique also allows for early control of emissary veins and an inside-out identification of the lambdoid sutures. Endoscopic visualization is optimized to reduce the risk of blood loss, especially because circulating blood volume is very limited in these young infants.

The video can be found here:

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Edward S. Ahn and Liliana Goumnerova


Endoscopic biopsy is an important minimally invasive method of diagnosis in the initial management of lesions in children with intraventricular and periventricular tumors. The procedure can be performed in conjunction with CSF-diverting procedures for obstructive hydrocephalus. The authors present their single-institution experience in a predominantly pediatric series with respect to diagnostic efficacy, utility in guiding treatment plans, and safety.


A retrospective review was conducted in a consecutive series of patients who underwent endoscopic biopsy of brain tumors during a 13-year period.


There were 33 endoscopic biopsies in 31 patients (16 males and 15 females). The average age of the patients was 11.3 years, with a mean follow-up duration of 2.4 years. The majority of biopsies were performed in conjunction with CSF-diverting procedures, such as endoscopic third ventriculostomy or fenestration of the septum pellucidum. Overall, 23 (70%) of 33 biopsies were diagnostic, with results that directed subsequent treatment. When stratified by tumor location, biopsy samples obtained in the lateral ventricle or pineal region were more favorable toward a successful diagnosis than those in the thalamus or tectal region. In 4 cases, elevated CSF tumor marker levels led to modification of the diagnosis and appropriate adjustment of treatment. The endoscopic third ventriculostomy success rate was 82.4%. There were 2 major complications (6.1%), which resulted in neurological deficits. There were no procedure-related deaths.


Endoscopic biopsy is an effective means of diagnosis of brain tumors in children. The diagnostic power may be more favorable with tumors in the lateral ventricle or pineal region. Collection of CSF during the procedure for tumor marker analysis is an integral component of diagnosis.

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Waleed Brinjikji, Edward S. Ahn, Marc C. Patterson, and Giuseppe Lanzino

Spinal cord intramedullary arteriovenous malformations (AVMs) have classically been considered congenital lesions that are present from birth. The reason for this dogmatic principal is the fact that a vast majority of these lesions present in pediatric and young adult patients. Interestingly, while many authors have demonstrated the development of de novo nidus-type brain AVMs, there have been no reported cases of a de novo intramedullary or perimedullary AVM of the spine. In this paper the authors describe what they believe to be the first reported case of a de novo AVM of the spinal cord in a young patient who underwent serial imaging from birth for evaluation of a syrinx. Potential pathophysiological mechanisms for the development of de novo vascular malformations of the spinal cord are discussed.

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Vivek Mehta, Joshua Bakhsheshian, Amir H. Dorafshar, and Edward S. Ahn

The authors describe the case of a boy with Muenke syndrome, an autosomal dominant disorder associated with craniosynostosis. The family history was significant for syndromic craniosynostosis in the patient’s maternal grandmother, who died in adulthood after a craniofacial reconstruction. The patient, her grandson, underwent craniofacial reconstruction surgery at the age of 9 months and developed upward transtentorial herniation. Imaging findings revealed remote cerebellar hemorrhage after a large quantity of supratentorial CSF was drained during postoperative Day 1. The clinical course was further complicated by cerebral sinus thrombosis, which was diagnosed after a fourth surgical procedure. Upward transtentorial herniation can occur when a significant increase in intracranial pressure in the posterior fossa causes displacement of the central lobule and superior surfaces of the cerebellum upward through the incisura tentorii. This is a rare but well-documented phenomenon that commonly occurs in the setting of an expansive posterior fossa lesion or excessive supratentorial CSF loss. To help clinicians recognize and prevent this rare but potentially fatal complication, the authors review the postulated mechanisms by which this process may occur.

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Edward S. Ahn, R. Michael Scott, Richard L. Robertson Jr., and Edward R. Smith


Chorea is a movement disorder characterized by brief, irregular, involuntary contractions that appear to flow from 1 muscle to another. There are a limited number of reports in the literature that have linked moyamoya disease and chorea. The authors describe their experience in treating moyamoya disease in patients in whom chorea developed as part of the clinical presentation.


The authors conducted a retrospective review of a consecutive series of 316 children who underwent pial synangiosis revascularization for moyamoya disease at the Boston Children's Hospital.


Of 316 surgically treated patients with moyamoya disease, 10 (3.2%; 6 boys and 4 girls) had chorea as a part of their presentation. The average age at surgical treatment was 9.9 years (range 3.8–17.9 years). All patients had evidence of hypertrophied lenticulostriate collateral vessels through the basal ganglia on preoperative angiography and/or MRI on affected sides. Two patients had cystic lesions in the basal ganglia. Nine patients underwent bilateral craniotomies for pial synangiosis, and 1 patient underwent a single craniotomy for unilateral disease. Follow-up was available in 9 patients (average 50.1 months). The mean duration of chorea was 1.36 years (range 2 days to 4 years), with resolution of symptoms in all patients. One patient developed chorea 3 years after surgical treatment, 4 patients had transient chorea that resolved prior to surgery, and 5 patients experienced resolution of the chorea after surgery (average 13 months).


The authors describe children with moyamoya disease and chorea as part of their clinical presentation. The data suggest that involvement of the basal ganglia by the hypertrophied collateral vessels contributes to the development of chorea, which can wax or wane depending on disease stage or involution of the vessels after revascularization surgery. In most patients, however, the chorea improves or disappears about 1 year after presentation.