Management of Pre-existing Ventriculoperitoneal Shunt in Posterior Vault Distraction for Lambdoid Craniosynostosis: A Case Report and Technical Note.

Posterior vault distraction osteogenesis (DO) is an emerging treatment option for craniosynostosis. Operative nuances detailing surgical management are being described with increasing use and experience. In this article, we discuss the surgical management of an 8-month-old male with a ventriculoperitoneal shunt (VPS) diagnosed with bilateral lambdoid craniosynostosis and Chiari I malformation. The patient underwent successful bilateral posterior fossa DO without surgical re-implantation of the shunt. Pre- and post-operative imaging confirmed no migration of the VPS. Intracranial volume increased by 20.1% and posterior fossa volume increased by 39.9%. Our experience illustrates that posterior vault DO can be done safely in the setting of a parieto-occipital VPS, in a single operative setting, without the need of additional procedures.

Intraoperative CT for Neuronavigation Guidance and Confirmation of Foramen Ovale Cannulation for Glycerol Trigeminal Rhizotomy: A Technical Report and Case Series.

Glycerol rhizotomy was originally described as an initial surgical treatment for trigeminal neuralgia after the failure of medical therapy. Here we describe its use as a salvage procedure, typically after failure of multiple other modalities including microvascular decompression, stereotactic radiosurgery, and/or other percutaneous procedures. Foramen ovale cannulation as a "salvage procedure" may be complicated by lack of cerebrospinal fluid (CSF) return despite adequate cannulation of the foramen ovale, making conventional fluoroscopic confirmation of adequate needle placement less certain. In this article, we describe the application of intraoperative CT, fused with high-resolution preoperative CT/MRI for neuronavigation to accurately cannulate the foramen ovale and Meckel's cave for glycerol rhizotomy. Intraoperative CT, again fused with high-resolution preoperative CT and MRI studies, was then used to confirm accurate trajectory through the foramen ovale and the adequate location of the needle tip in Meckel's cave before injecting glycerol. We present our initial experience with 14 patients who underwent glycerol rhizotomy by these techniques depending on intraoperative CT. It appears that intraoperative CT-guided neuronavigation provides a practical, reliable, and accurate route to the foramen ovale and aids in the confirmation of adequate needle placement even when there is a lack of CSF return. These methods may be especially useful for difficult cannulations typical in salvage procedures. In an era of feasible intraoperative guidance, with advanced stereotactic planning software allowing the fusion of intraoperative CT with high-resolution preoperative CT and MRI datasets, these techniques can be applied to foramen ovale cannulation for glycerol rhizotomy without major modification.

Three-Dimensional Volumetric Changes in Posterior Vault Distraction With Distraction Osteogenesis.

OBJECT: Distraction osteogenesis (DO) may allow for maximal volumetric expansion in the posterior vault (PV) by overcoming viscoelastic forces of overlying soft tissues. Little evidence exists regarding surgical planning and anticipated 3D volumetric changes pre- and post-operatively. We aim to study the volumetric changes occurring in PV distraction in lambdoid craniosynostosis. METHODS: From 2007 to 2019, a single institution retrospective review revealed 232 craniosynostosis patients. Fourteen demonstrated lambdoid synostosis (6%), and of those, 11 patients were included in the study due to treatment with PVDO or representative sample. Six patients had unilateral synostosis and 5 had bilateral synostosis. Imaging protocol for PVDO patients included preoperative head CT within 1 month of surgery and 8 weeks following distraction cessation with weekly skull plain films. 3D volumetric analyses were performed on pre and postoperative head CT using 3D Slicer software. RESULTS: Posterior fossa volume (PFV) increased by 38.7% and foramen magnum area increased by 26.9% postoperatively. Unilateral lambdoid craniosynostosis patients had greater increases in PFV versus bilateral lambdoid craniosynostosis patients (63.5% versus 8.9%, P = 0.007). Osteotomy to the asterion was more effective in increasing PFV versus osteotomy to foramen magnum (P = 0.050). Placement of distractor in the inferior third of the lambdoid suture is more effective in increasing PFV versus placement in the middle or top third of the suture (P = 0.041). CONCLUSIONS: Highest volumetric increases are seen in unilateral lambdoid synostosis. Extending osteotomy beyond the asterion is not necessary for maximal PV volumetric gain. Placement of distractor in the inferior third of the suture leads to maximal PV volumetric gains.

An incidental pure arterial malformation in a child: case report and review of the literature.

PURPOSE: Pure arterial malformations of the brain are rare vascular lesions. METHODS: We present a 10-year-old healthy boy who presented with an incidental finding of pure arterial malformation. RESULTS: Our case seems to represent the second description of pure arterial malformation discovered incidentally in a child. CONCLUSION: We review the clinical presentation, angiographic findings, and management of our case in the context of other reported pediatric cases.

Protocol-driven prevention of perioperative hypothermia in the pediatric neurosurgical population.

OBJECTIVE: Perioperative hypothermia (PH) is a preventable, pathological, and iatrogenic state that has been shown to result in increased surgical blood loss, increased surgical site infections, increased hospital length of stay, and patient discomfort. Maintenance of normothermia is recommended by multiple surgical quality organizations; however, no group yet provides an ergonomic, evidence-based protocol to reduce PH for pediatric neurosurgery patients. The authors' aim was to evaluate the efficacy of a PH prevention protocol in the pediatric neurosurgery population. METHODS: A prospective, nonrandomized study of 120 pediatric neurosurgery patients was performed. Thirty-eight patients received targeted warming interventions throughout their perioperative phases of care (warming group-WG). The remaining 82 patients received no extra warming care during their perioperative period (control group-CG). Patients were well matched for age, sex, and preparation time intraoperatively. Hypothermia was defined as < 36°C. The primary outcome of the study was maintenance of normothermia preoperatively, intraoperatively, and postoperatively. RESULTS: WG patients were significantly warmer on arrival to the operating room (OR) and were 60% less likely to develop PH (p < 0.001). Preoperative forced air warmer use both reduced the risk of PH at time 0 intraoperatively and significantly reduced the risk of any PH intraoperatively (p < 0.001). All patients, regardless of group, experienced a drop in core temperature until a nadir occurred at 30 minutes intraoperatively for the WG and 45 minutes for the CG. At every time interval, from preoperatively to 120 minutes intraoperatively, CG patients were between 2 and 3 times more likely to experience PH (p < 0.001). All patients were warm on arrival to the postanesthesia care unit regardless of patient group. CONCLUSIONS: Preoperative forced air warmer use significantly increases the average intraoperative time 0 temperature, helping to prevent a fall into PH at the intraoperative nadir. Intraoperatively, a strictly and consistently applied warming protocol made intraoperative hypothermia significantly less likely as well as less severe when it did occur. Implementation of a warming protocol necessitated only limited resources and an OR culture change, and was well tolerated by OR staff.

Tenosynovial Giant Cell Tumor of the Cervical Spine: Case Report and Review of the Literature.

Tenosynovial giant cell tumor (TGCT) is a rare entity that is not well described in the neurosurgical literature. We present a case of a 37-year-old woman with a diffuse subtype TGCT of the cervical spine, affecting the left cervical 6-7 facet joint, with co-incidental cervical trauma. Initial management consisted of subtotal resection and cervical stabilization with cervical 6 to 7 laminectomy, and cervical 4 to thoracic 2 posterior instrumented fusion. Gross total resection was achieved at a later date with a plan for postoperative radiation to prevent a recurrence. The patient was lost to follow-up for radiation treatment and returned 2.5 years later with minor symptoms and recurrence at the surgical site.

Posterior transdural approach for odontoidectomy in a child: case report.

The transoral transpharyngeal approach is the standard approach to resect the odontoid process and decompress the cervicomedullary spinal cord. There are some significant risks associated with this approach, however, including infection, CSF leak, prolonged intubation or tracheostomy, need for nasogastric tube feeding, extended hospitalization, and possible effects of phonation. Other ventral approaches, such as transmandibular and circumglossal, endoscopic transcervical, and endoscopic transnasal, are also viable alternatives but are technically challenging or may still traverse the nasopharyngeal cavity. Far-lateral and posterior extradural approaches to the craniocervical junction require extensive soft-tissue dissection. Recently, a posterior transdural approach was used to resect retro-odontoid cysts in 3 adult patients. The authors present the case of a 12-year-old girl with Down syndrome and significant spinal cord compression due to basilar invagination and a retro-flexed odontoid process. A posterior transdural odontoidectomy prior to occiptocervical fusion was performed. At 12 months after surgery, the authors report satisfactory clinical and radiographic outcomes with this approach.

Repair of a large primary subtemporal encephalocele in a 3-year-old child: case report.

Primary encephaloceles (PEs) present only rarely in the temporal region; in the rare instance that they project through the floor of the middle fossa they are secondary. In this case report the authors report on the management of a giant PE extending through the floor of the middle fossa.An 8-month-old boy presented to the authors' service with a large PE projecting into his neck through a missing left middle fossa floor; the lesion was causing significant meta-, dys-, and hypoplasia of the structures of the anterolateral neck on that side. Surgical goals for this patient included the following: 1) removal of potentially epileptogenic and dysfunctional tissue; 2) preservation of cranial nerves; 3) prevention of cognitive decline or iatrogenic deficit; 4) prevention of CSF leak; 5) reconstruction of skull base; 6) prevention of airway and swallowing compromise; and 7) cosmesis. After a multidisciplinary evaluation with ENT, plastic surgery, and neurology, an operation was performed using a preauricular infratemporal approach when the patient was 3 years old. Gliotic tissue was resected and amygdala, hippocampus, and middle cerebral artery were preserved.The immediate results of the operation showed good immediate outcome. Seizure freedom and neurodevelopment outcomes remain to be seen at follow-up.

Neoadjuvant chemotherapy for atypical teratoid rhabdoid tumors: case report.

Atypical teratoid rhabdoid tumors (ATRTs) are a rare pediatric brain tumor with high mortality rate. Several large series have reported achieving gross-total resection (GTR) in less than 50% of patients due to the lesions' large size, vascularity, and limited blood volume in young patients. While neoadjuvant chemotherapy for choroid plexus carcinomas in pediatric patients has become widely accepted, it has not been used as widely for other pediatric brain tumors. To the best of the authors' knowledge, there are only 3 published cases of neoadjuvant chemotherapy for ATRTs. In the present report, the authors present a fourth case of neoadjuvant chemotherapy for ATRT and review the available literature on this strategy. A 17-month-old child presented with a left ventricular ATRT for which imaging raised concern for a highly vascularized tumor. The authors undertook neoadjuvant chemotherapy with 2 cycles of Head Start II therapy, which reduced the size of the ventricular tumor by 35% and decreased the vascularity of the lesion on imaging. The estimated blood loss during resection was 425 ml and GTR was achieved. The patient continued with postoperative chemotherapy but suffered an on-therapy recurrence. While higher-quality data are necessary, available evidence suggests that neoadjuvant chemotherapy can reduce the size and vascularity of ATRTs and facilitate a surgical avenue for large or "inoperable" tumors.

Congenital myotonic dystrophy: ventriculomegaly and shunt considerations for the pediatric neurosurgeon.

PURPOSE: Ventriculomegaly in infants with congenital myotonic dystrophy (CDM) is common, and the neurosurgical determination of shunting is complex. The natural history of CDM-associated ventriculomegaly from prenatal to natal to postnatal stages is poorly known. The relationship between macrocephaly and ventriculomegaly, incidence of shunt necessity, and early mortality outcomes lack pooled data analysis. This study aims to review clinical features and pathophysiology of CDM, with emphasis on ventriculomegaly progression, ventriculomegaly association with macrocephaly, and incidence of shunting. METHODS: This is a literature review with pooled data analysis and case report. RESULTS: One hundred four CDM patients were reviewed in 13 articles that mentioned CDM with ventriculomegaly and/or head circumference. Data was very limited: only 7 patients had data on the presence or absence of prenatal ventriculomegaly, 97 on ventriculomegaly at birth, and 32 on whether or not the ventricles enlarged post-natally. Three patients of 7 (43 %) had pre-natally diagnosed ventriculomegaly, 43 of 97 (44 %) had ventriculomegaly at birth, and only 5 of 32 (16 %) had progressive enlargement of ventricles post-natally. Only 5 of 104 patients had a documented shunt placement: 1 for obstructive, 1 for a post-hemorrhagic communicating, 2 for a communicating hydrocephalus without hemorrhage, and 1 with unknown indication. Of 13 macrocephalic patients with data about ventricular size, 12 had ventriculomegaly. CONCLUSIONS: Ventriculomegaly occurs regularly with CDM but most often does not require CSF diversion. Decisions regarding neurosurgical intervention will necessarily be based on limited information, but shunting should only occur once dynamic data confirms hydrocephalus.

Tail function during arboreal quadrupedalism in squirrel monkeys (Saimiri boliviensis) and tamarins (Saguinus oedipus).

The need to maintain stability on narrow branches is often presented as a major selective force shaping primate morphology, with adaptations to facilitate grasping receiving particular attention. The functional importance of a long and mobile tail for maintaining arboreal stability has been comparatively understudied. Tails can facilitate arboreal balance by acting as either static counterbalances or dynamic inertial appendages able to modulate whole-body angular momentum. We investigate associations between tail use and inferred grasping ability in two closely related cebid platyrrhines-cotton-top tamarins (Saguinus oedipus) and black-capped squirrel monkeys (Saimiri boliviensis). Using high-speed videography of captive monkeys moving on 3.2 cm diameter poles, we specifically test the hypothesis that squirrel monkeys (characterized by grasping extremities with long digits) will be less dependent on the tail for balance than tamarins (characterized by claw-like nails, short digits, and a reduced hallux). Tamarins have relatively longer tails than squirrel monkeys, move their tails through greater angular amplitudes, at higher angular velocities, and with greater angular accelerations, suggesting dynamic use of tail to regulate whole-body angular momentum. By contrast, squirrel monkeys generally hold their tails in a comparatively stationary posture and at more depressed angles, suggesting a static counterbalancing mechanism. This study, the first empirical test of functional tradeoffs between grasping ability and tail use in arboreal primates, suggests a critical role for the tail in maintaining stability during arboreal quadrupedalism. Our findings have the potential to inform our functional understanding of tail loss during primate evolution.