Faculty Bibliography

OBJECT Intrathecal baclofen (ITB) is a valuable therapeutic option for patients with spasticity and dystonia. The techniques that place an ITB pump catheter into the subcutaneous fat of a lumbar incision are well described. Because patients who require ITB often have low body fat content, they may be predisposed to catheter-related complications. The senior author used a novel technique to place the catheter in a paraspinal subfascial fashion, and the short-term results were previously published. That study demonstrated no development of hardware erosions, catheter migrations, or CSF leaks within an average follow-up of 5 months. This study followed up on those initial findings by looking at the long-term outcomes since this technique was introduced. METHODS Using the institutional review board-approved protocol, the electronic medical records were reviewed retrospectively for all patients who underwent paraspinal subfascial catheter placement by the senior author. Patients received follow-up with the surgeon at 2 weeks postoperatively and were followed routinely by their physiatrist thereafter. RESULTS Of the 43 patients identified as having undergone surgery by the senior author using the paraspinal subfascial technique between July 2010 and February 2014, 12 patients (27.9%) required reoperation. There were 5 patients (11.6%) who had complications related to the catheter or lumbar incision. No hardware erosions or CSF leaks were identified. These patients received a median follow-up of 3.0 years, with 30 of 43 patients receiving follow-up over 2.0 years. CONCLUSION This follow-up study suggests that the technique of paraspinal subfascial catheter placement translates to long-term decreases in CSF leakage and complications from erosion, infection, and also catheter malfunctions. It does not seem to affect the overall rate of complications.

Objective: We report the feasibility and outcomes of endoscopic resection of select intraventricular tumors in children. Methods: The clinical characteristics of 11 children with solid intraventricular tumors who underwent tumor resection were reviewed. 12 procedures were performed. Results: Gross total resection was achieved in 11 of 12 cases (92%). Maximal diameter ranged from 9-26 mm (mean 16.6 mm). Pathology included subependymal giant cell astrocytomas (SEGA), ependymomas, non-germinomatous germ cell tumor (NGGCT) and pilocytic astrocytoma. Mean follow-up was 35 months (range 10-109 months). All patients returned to their neurological baseline following surgery. Local tumor recurrence occurred in one patient and distant recurrence in another. Complications occurred in one patient, no permanent morbidity or mortality occurred. Hydrocephalus was present preoperatively in 5 cases and was treated with tumor removal alone or with additional endoscopic third ventriculostomy. No patient required a ventriculoperitoneal shunt. Conclusion: Neuroendoscopic gross-total resection of solid intraventricular tumors is a safe procedure in carefully selected pediatric patients

A 4-year-old girl with a history of thoracic meningocele repair at the age of 3 months presented with progressive myelopathy. An intramedullary thoracic epidermoid was identified on MRI. The patient underwent excision of the epidermoid and subsequently returned to neurological baseline. This case illustrates the potential for delayed development of intraspinal epidermoid after initial repair of a simple meningocele.

We present the first case of pediatric intracranial M abscessus infection in a 16-month-old female with neurofibromatosis type-1. We describe a successful treatment regimen including excisional biopsy combined with high dose steroids and 16 weeks of triple antimicrobial therapy that resulted in clinical cure and an excellent neurologic outcome.

BACKGROUND: Activation of the RAS-RAF-MEK-ERK signaling pathway is thought to be the key driver of pediatric low-grade astrocytoma (PLGA) growth. Sorafenib is a multikinase inhibitor targeting BRAF, VEGFR, PDGFR, and c-kit. This multicenter phase II study was conducted to determine the response rate to sorafenib in patients with recurrent or progressive PLGA. METHODS: Key eligibility criteria included age >/=2 years, progressive PLGA evaluable on MRI, and at least one prior chemotherapy treatment. Sorafenib was administered twice daily at 200 mg/m2/dose (maximum of 400 mg/dose) in continuous 28-day cycles. MRI, including 3-dimensional volumetric tumor analysis, was performed every 12 weeks. BRAF molecular testing was performed on tumor tissue when available. RESULTS: Eleven patients, including 3 with neurofibromatosis type 1 (NF1), were evaluable for response; 5 tested positive for BRAF duplication. Nine patients (82%) came off trial due to radiological tumor progression after 2 or 3 cycles, including 3 patients with confirmed BRAF duplication. Median time to progression was 2.8 months (95% CI, 2.1-31.0 months). Enrollment was terminated early due to this rapid and unexpectedly high progression rate. Tumor tissue obtained from 4 patients after termination of the study showed viable pilocytic or pilomyxoid astrocytoma. CONCLUSIONS: Sorafenib produced unexpected and unprecedented acceleration of tumor growth in children with PLGA, irrespective of NF1 or tumor BRAF status. In vitro studies with sorafenib indicate that this effect is likely related to paradoxical ERK activation. Close monitoring for early tumor progression should be included in trials of novel agents that modulate signal transduction.

BACKGROUND:: Surgical resection of epileptic foci relies on accurate localization of the epileptogenic zone, often achieved by subdural and depth electrodes. Our epilepsy center has treated selected children with poorly localized medically refractory epilepsy with a staged surgical protocol, with at least one phase of invasive monitoring for localization and resection of epileptic foci. OBJECTIVE:: To evaluate the safety of staged surgical treatments for refractory epilepsy among children. METHODS:: Data were retrospectively collected, including surgical details and complications of all patients who underwent invasive monitoring. RESULTS:: 161 children underwent 200 admissions including staged procedures (>1 surgery during one hospital admission), and 496 total surgeries. Average age at surgery was 7y (8m-16.5y). 250 surgeries included resections (and invasive monitoring), and 189 involved electrode placement only. Cumulative total number of surgeries per patient was 2-10 (average 3). Average duration of monitoring was 10 days (1-30). There were no deaths. Follow-up ranged from 1m to 10y. Major complications included unexpected new permanent mild neurological deficits (2%/admission), CNS or bone flap infections (1.5%/admission), intracranial hemorrhage, CSF leak, and a retained strip (each 0.5%/admission). Minor complications included bone absorption (5%/admission), positive surveillance sub/epidural cultures in asymptomatic patients (5.5%/admission), non-infectious fever (5%/admission), and wound complications (3%/admission). 30 complications necessitated additional surgical treatment. CONCLUSION:: Staged epilepsy surgery, with invasive electrode monitoring, is safe in children with poorly localized medically refractory epilepsy. The rate of major complications is low, and appears comparable to that associated with other elective neurosurgical procedures.

Object Subependymal giant cell astrocytomas (SEGAs) are benign tumors, most commonly associated with tuberous sclerosis complex (TSC). The vast majority of these tumors arise from the lateral ependymal surface adjacent to the foramen of Monro, therefore potentially encroaching on one or both foramina, and resulting in obstructive hydrocephalus that necessitates surgical decompression. The indications for surgery, intraoperative considerations, and evolution of the authors' management paradigm are presented. Methods Patients with TSC who underwent craniotomy for SEGA resection at New York University Langone Medical Center between January 1997 and March 2011 were identified. Preoperative imaging, clinical characteristics, management decisions, operative procedures, and outcomes were reviewed. Results Eighteen patients with TSC underwent 22 primary tumor resections for SEGAs. The indication for surgery was meaningful radiographic tumor progression in 16 of 21 cases. The average age at the time of operation was 10.3 years. Average follow-up duration was 52 months (range 12-124 months). The operative approach was intrahemispheric-transcallosal in 16 cases, transcortical-transventricular in 5, and neuroendoscopic in 1. Nine tumors were on the right, 9 on the left, and 3 were bilateral. Gross-total resection was documented in 16 of 22 cases in our series, with radical subtotal resection achieved in 4 cases, and subtotal resection (STR) in 2 cases. Two patients had undergone ventriculoperitoneal shunt placement preoperatively and 7 patients required shunt placement after surgery for moderate to severe ventriculomegaly. Two patients experienced tumor progression requiring reoperation; both of these patients had initially undergone STR. Conclusions The authors present their management strategy for TSC patients with SEGAs. Select patients underwent microsurgical resection of SEGAs with acceptable morbidity. Gross-total resection or radical STR was achieved in 90.9% of our series (20 of 22 primary tumor resections), with no recurrences in this group. Approximately half of our patient series required CSF diversionary procedures. There were no instances of permanent neurological morbidity associated with surgery.