Isolated thoracic syrinx in children with Chiari I malformation

INTRODUCTION

Syrinx has been reported in 25-85 % of children with Chiari malformation type I (CMI), and it is most commonly cervical in location. As a result, cervical MRI is routinely included in an evaluation for CMI. Isolated thoracic syrinx without involvement of the cervical cord in this population is uncommon but clinically important because its presence may influence the decision to operate, surgical techniques employed, or interpretation of follow-up imaging. The purpose of this study was to determine the incidence of isolated thoracic syrinx in a large group of children evaluated for CMI.

METHODS

We retrospectively reviewed all patients under 21 years of age who were evaluated for CMI at Columbia University/Morgan Stanley Children's Hospital of New York from 1998 to 2013. All patients underwent MRI of the entire spine as part of the CMI evaluation, regardless of whether surgery was planned. The proportion of patients exhibiting isolated thoracic syrinx was determined. Presenting signs, symptoms, and imaging findings were then studied in an attempt to identify any clinical features associated with isolated thoracic syrinx.

RESULTS

We identified 266 patients evaluated over the study period. One-hundred thirty-two patients (50 %) presented with a syrinx, and 12 patients (4.5 % of all patients evaluated and 9.1 % of all patients with a syrinx) had an isolated thoracic syrinx. Demographic variables, clinical presentation, and extent of tonsillar ectopia showed great heterogeneity in this group, and no factor was consistently associated with isolated thoracic syrinx.

CONCLUSIONS

Isolated thoracic syrinx is an uncommon but clinically significant finding in children with CMI. Our data demonstrate that the presence of a CMI-related thoracic syrinx cannot be reliably predicted clinically and is therefore likely to be missed in patients who do not undergo complete spinal cord imaging. MRI of the entire spinal cord should be considered for all children undergoing initial evaluation for CMI.

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.

Delayed resolution of syrinx after posterior fossa decompression without dural opening in children with Chiari malformation Type I

OBJECT Chiari malformation Type I (CM-I) is associated with a syrinx in 25%-85% of patients. Although posterior fossa decompression (PFD) without dural opening is an accepted treatment option for children with symptomatic CM-I, many surgeons prefer to open the dura if a syrinx exists. The purpose of this study was to investigate the frequency and timing of syrinx resolution in children undergoing PFD without dural opening for CM-I. METHODS A retrospective review of 68 consecutive pediatric patients with CM-I and syringomyelia who underwent PFD without dural opening was conducted. Patient demographics, presenting symptoms and signs, radiographic findings, and intraoperative ultrasound and neuromonitoring findings were studied as well as the patients' clinical and radiographic follow-up. RESULTS During the mean radiographic follow-up period of 32 months, 70% of the syringes improved. Syrinx improvement occurred at a mean of 31 months postoperatively. All patients experienced symptom improvement within the 1st year, despite only 26% of patients showing radiographic improvement during that period. Patients presenting with sensory symptoms or motor weakness had a higher likelihood of having radiographic syrinx improvement postoperatively. CONCLUSIONS In children with CM-I and a syrinx undergoing PFD without dural opening, syrinx resolution occurs in approximately 70% of patients. Radiographic improvement of the syrinx is delayed, but this does not correlate temporally with symptom improvement. Sensory symptoms or motor weakness on presentation are associated with syrinx resolution after surgery.

Ventral Decompression in Chiari Malformation, Basilar Invagination, and Related Disorders

Ventral brainstem compression is an uncommon clinical diagnosis seen by pediatric neurosurgeons and associated with Chiari malformation, type I. Presenting clinical symptoms often include headaches, lower cranial neuropathies, myelopathy, central sleep apnea, ataxia, and nystagmus. When ventral decompression is required, both open and endoscopic transoral/transnasal approaches are highly effective.

Outcomes after suboccipital decompression without dural opening in children with Chiari malformation Type I

OBJECT Symptomatic pediatric Chiari malformation Type I (CM-I) is most often treated with posterior fossa decompression (PFD), but controversy exists over whether the dura needs to be opened during PFD. While dural opening as a part of PFD has been suggested to result in a higher rate of resolution of CM symptoms, it has also been shown to lead to more frequent complications. In this paper, the authors present the largest reported series of outcomes after PFD without dural opening surgery, as well as identify risk factors for recurrence. METHODS The authors performed a retrospective review of 156 consecutive pediatric patients in whom the senior authors performed PFD without dural opening from 2003 to 2013. Patient demographics, clinical symptoms and signs, radiographic findings, intraoperative ultrasound results, and neuromonitoring findings were reviewed. Univariate and multivariate regression analyses were performed to determine risk factors for recurrence of symptoms and the need for reoperation. RESULTS Over 90% of patients had a good clinical outcome, with improvement or resolution of their symptoms at last follow-up (mean 32 months). There were no major complications. The mean length of hospital stay was 2.0 days. In a multivariate regression model, partial C-2 laminectomy was an independent risk factor associated with reoperation (p = 0.037). Motor weakness on presentation was also associated with reoperation but only with trend-level significance (p = 0.075). No patient with < 8 mm of tonsillar herniation required reoperation. CONCLUSIONS The vast majority (> 90%) of children with symptomatic CM-I will have improvement or resolution of symptoms after a PFD without dural opening. A non-dural opening approach avoids major complications. While no patient with tonsillar herniation < 8 mm required reoperation, children with tonsillar herniation at or below C-2 have a higher risk for failure when this approach is used.

Superior parietal lobule approach for choroid plexus papillomas without preoperative embolization in very young children

OBJECT Choroid plexus papillomas (CPPs) are rare neoplasms, often found in the atrium of the lateral ventricle of infants, and cause overproduction hydrocephalus. The extensive vascularity and medially located blood supply of these tumors, coupled with the young age of the patients, can make prevention of blood loss challenging. Preoperative embolization has been advocated to reduce blood loss and prevent the need for transfusion, but this mandates radiation exposure and the additional risks of vessel injury and stroke. For these reasons, the authors present their experience using the superior parietal lobule approach to CPPs of the atrium without adjunct therapy. METHODS A retrospective review was conducted of all children who presented to Columbia University/Morgan Stanley Children's Hospital of New York with a CPP in the atrium of the lateral ventricle and who underwent surgery using a superior parietal lobule approach without preoperative embolization. RESULTS Nine children were included, with a median age of 7 months. There were no perioperative complications or new neurological deficits. All patients had intraoperative blood loss of less than 100 ml, with a mean minimum hematocrit of 26.9% (range 19.6%-36.2%). No patients required a blood transfusion. The median follow-up was 39 months, during which time no patient demonstrated residual or recurrent tumor on MRI, nor did any have an increase in ventricular size or require CSF diversion. CONCLUSIONS The superior parietal lobule approach is safe and effective for very young children with CPPs in the atrium of the lateral ventricle. The results suggest that preoperative embolization is not essential to avoid transfusion or achieve overall good outcomes in these patients. This management strategy avoids radiation exposure and the additional risks associated with embolization.

Identification of targets for rational pharmacological therapy in childhood craniopharyngioma

Introduction

Pediatric adamantinomatous craniopharyngioma (ACP) is a histologically benign but clinically aggressive brain tumor that arises from the sellar/suprasellar region. Despite a high survival rate with current surgical and radiation therapy (75–95 % at 10 years), ACP is associated with debilitating visual, endocrine, neurocognitive and psychological morbidity, resulting in excheptionally poor quality of life for survivors. Identification of an effective pharmacological therapy could drastically decrease morbidity and improve long term outcomes for children with ACP.

Results

Using mRNA microarray gene expression analysis of 15 ACP patient samples, we have found several pharmaceutical targets that are significantly and consistently overexpressed in our panel of ACP relative to other pediatric brain tumors, pituitary tumors, normal pituitary and normal brain tissue. Among the most highly expressed are several targets of the kinase inhibitor dasatinib – LCK, EPHA2 and SRC; EGFR pathway targets – AREG, EGFR and ERBB3; and other potentially actionable cancer targets – SHH, MMP9 and MMP12. We confirm by western blot that a subset of these targets is highly expressed in ACP primary tumor samples.

Conclusions

We report here the first published transcriptome for ACP and the identification of targets for rational therapy. Experimental drugs targeting each of these gene products are currently being tested clinically and pre-clinically for the treatment of other tumor types. This study provides a rationale for further pre-clinical and clinical studies of novel pharmacological treatments for ACP. Development of mouse and cell culture models for ACP will further enable the translation of these targets from the lab to the clinic, potentially ushering in a new era in the treatment of ACP.

Pial synangiosis for moyamoya syndrome in children with sickle cell anemia: a comprehensive review of reported cases

OBJECT

Pediatric patients with sickle cell anemia (SCA) carry a significant risk of developing moyamoya syndrome (MMS) and brain ischemia. The authors sought to review the safety and efficacy of pial synangiosis in the treatment of MMS in children with SCA by performing a comprehensive review of all previously reported cases in the literature.

METHODS

The authors retrospectively reviewed the clinical and radiographic records in 17 pediatric patients with SCA treated at the Morgan Stanley Children's Hospital of New York (MSCHONY) who developed radiological evidence of MMS and underwent pial synangiosis between 1996 and 2012. The authors then added any additional reported cases of pial synangiosis for this population in the literature for a combined analysis of clinical and radiographic outcomes.

RESULTS

The combined data consisted of 48 pial synangiosis procedures performed in 30 patients. Of these, 27 patients (90%) presented with seizure, stroke, or transient ischemic attack, whereas 3 (10%) were referred after transcranial Doppler screening. At the time of surgery, the median age was 12 years. Thirteen patients (43%) suffered an ischemic stroke while on chronic transfusion therapy. Long-term follow-up imaging (MR angiography or catheter angiography) at a mean of 25 months postoperatively was available in 39 (81%) treated hemispheres. In 34 (87%) of those hemispheres there were demonstrable collateral vessels on imaging. There were 4 neurological events in 1590 cumulative months of follow-up, or 1 event per 33 patient-years. In the patients in whom complete data were available (MSCHONY series, n = 17), the postoperative stroke rate was reduced more than 6-fold from the preoperative rate (p = 0.0003).

CONCLUSIONS

Pial synangiosis in patients with SCA, MMS, and brain ischemia appears to be a safe and effective treatment option. Transcranial Doppler and/or MRI screening in asymptomatic patients with SCA is recommended for the diagnosis of MMS.

Resection of an upper cervical aneurysmal bone cyst and spinal reconstruction using a midline mandibular osteotomy in a pediatric patient

The authors report on the surgical management of an extensive lesion of the upper cervical spine that required an uncommon transmandibular approach to facilitate exposure, resection, and stabilization in a pediatric patient. A 6-year-old boy with a large aneurysmal bone cyst of the C-2 vertebra presented with progressive weakness and right-sided neck pain. The lesion extended laterally into the soft tissue of the neck, inferiorly to C-4, and posteriorly around the spinal cord. A transmandibular osteotomy was performed to provide adequate exposure for complete resection of the mass and anterior C1-3 instrumentation and fusion. Subsequently, the patient underwent occiput to C-4 posterior instrumentation and fusion. The patient tolerated the operation well and had regained all function at 3 and 11 months' follow-up. No neurological complications or problems of speech, swallowing, or respiration occurred. Even in pediatric patients, the transmandibular approach for the treatment of upper cervical spine lesions is an effective method of maximizing exposure for complex lesions requiring resection and stabilization.

Transnasal endoscopic approach to the pediatric craniovertebral junction and rostral cervical spine: case series and literature review

The endoscopic transnasal approach to the rostral pediatric spine and craniovertebral junction is a relatively new technique that provides an alternative to the traditional transoral approach to the anterior pediatric spine. In this case series, the authors provide 2 additional examples of patients undergoing endoscopic transnasal odontoidectomies for ventral decompression of the spinal cord. Both patients would have required transection of the palate to undergo an effective transoral operation, which can be a cause of significant morbidity. In one case, transnasal decompression was initially incomplete, and decompression was successfully achieved via a second endoscopic transnasal operation. Both cases resulted in significant neurological recovery and stable long-term spinal alignment. The transnasal approach benefits from entering into the posterior pharynx at an angle that often reduces the length of postoperative intubation and may speed a patient's return to oral intake. Higher reoperation rates are a concern for many endoscopic approaches, but there are insufficient data to conclude if this is the case for this procedure. Further experience with this technique will provide a better understanding of the indications for which it is most effective. Transcervical and transoral endoscopic approaches have also been reported and provide additional options for pediatric anterior cervical spine surgery.

Reduction in upper-extremity tone after lumbar selective dorsal rhizotomy in children with spastic cerebral palsy

OBJECT

Randomized clinical trials have established that lumbar selective dorsal rhizotomy (SDR) reduces lower-extremity tone and improves functional outcome in children with spastic cerebral palsy. Significant data exist to support a secondary effect on upper-extremity function in patients with upper-extremity spasticity. The effects of SDR on upper-extremity tone, however, are not well characterized. In this report, the authors sought to assess changes in upper-extremity tone in individual muscle groups after SDR and tried to determine if these changes could be predicted preoperatively.

METHODS

The authors retrospectively reviewed 42 children who underwent SDR at Columbia University Medical Center/Morgan Stanley Children's Hospital of NewYork-Presbyterian between 2005 and 2011. Twenty-five had upper-extremity spasticity. All underwent pre- and postoperative examination for measuring tone (Modified Ashworth Scale) and assessing functional outcome. Follow-up examinations with therapists were performed at least once at a minimum of 2 months postoperatively (mean 15 months).

RESULTS

In the upper extremities, 23 (92%) of 25 patients had improvements of at least 1 Ashworth point in 2 or more independent motor groups on the Modified Ashworth Scale, and 12 (71%) of 17 families surveyed reported increases in motor control or spontaneous movement. The mean Modified Ashworth Scale scores for all upper-extremity muscle groups demonstrated an improvement from 1.34 to 1.22 (p < 0.001). Patients with a mean preoperative upper-extremity tone of 1.25-1.75 were most likely to benefit from reduction in tone (p = 0.0019). Proximal and pronator muscle groups were most likely to demonstrate reduced tone.

CONCLUSIONS

In addition to improvements in lower-extremity tone and function, SDR has demonstrable effects on upper extremities. Greater than 90% of our patients with elevated upper-extremity tone demonstrated reduction in tone in at least 2 muscle groups postoperatively. Patients with a mean Modified Ashworth Scale upper-extremity score of 1.25-1.75 may encounter the greatest reduction in upper-extremity tone.

Inhibition of caveolin-1 restores myeloid cell function in human glioblastoma

Background

Gliomas are the most common primary brain tumor in both children and adults. The prognosis for glioblastoma (GBM), the most common type of malignant glioma, has remained dismal, with median survival a little over one year despite maximal therapy with surgery, chemotherapy, and radiation. Although immunotherapy has become increasingly successful against many systemic tumors, clinical efficacy against brain tumors has been limited. One reason for this is an incomplete understanding of the local immunologic tumor microenvironment, particularly the function of large numbers of infiltrating myeloid derived cells. Monocytes/microglia are myeloid derived immunomodulatory cells, and they represent the predominant infiltrating immune cell population in gliomas. Our group has previously demonstrated using complementary invitro and invivo approaches that GBM tumor cells polarize tumor-associated myeloid cells (TAMs) and suppress their immunostimulatory function.

Methods and Results

To better understand the mechanisms responsible for this immunosuppression, we used gene expression profiling of stimulated monocytes in the presence or absence of GBM tumor cells. Our analysis identified caveolin-1 (CAV1), a plasma membrane molecule with pleiotropic functions, as significantly up-regulated in monocytes in the presence of GBMs. We validated these findings exvivo by confirming up-regulation of CAV1 in TAMs isolated from GBMs immediately after surgical resection. Finally, we demonstrate that siRNA inhibition of CAV1 restores myeloid cell function, as measured by TNF-alpha secretion, in the presence of GBMs.

Conclusions

Restoration of TAM function through pharmacologic blockage of CAV1 may facilitate more successful immunotherapeutic strategies directed against a variety of solid human tumors infiltrated by TAMs.

The immune cell infiltrate populating meningiomas is composed of mature, antigen-experienced T and B cells

BACKGROUND

Meningiomas often harbor an immune cell infiltrate that can include substantial numbers of T and B cells. However, their phenotype and characteristics remain undefined. To gain a deeper understanding of the T and B cell repertoire in this tumor, we characterized the immune infiltrate of 28 resected meningiomas representing all grades.

METHODS

Immunohistochemistry was used to grossly characterize and enumerate infiltrating lymphocytes. A molecular analysis of the immunoglobulin variable region of tumor-infiltrating B cells was used to characterize their antigen experience. Flow cytometry of fresh tissue homogenate and paired peripheral blood lymphocytes was used to identify T cell phenotypes and characterize the T cell repertoire.

RESULTS

A conspicuous B and T cell infiltrate, primarily clustered in perivascular spaces, was present in the microenvironment of most tumors examined. Characterization of 294 tumor-infiltrating B cells revealed clear evidence of antigen experience, in that the cardinal features of an antigen-driven B cell response were present. Meningiomas harbored populations of antigen-experienced CD4+ and CD8+ memory/effector T cells, regulatory T cells, and T cells expressing the immune checkpoint molecules PD-1 and Tim-3, indicative of exhaustion. All of these phenotypes were considerably enriched relative to their frequency in the circulation. The T cell repertoire in the tumor microenvironment included populations that were not reflected in paired peripheral blood.

CONCLUSION

The tumor microenvironment of meningiomas often includes postgerminal center B cell populations. These tumors invariably include a selected, antigen-experienced, effector T cell population enriched by those that express markers of an exhausted phenotype.

Profound tumor-specific Th2 bias in patients with malignant glioma

Background

Vaccination against tumor-associated antigens is one promising approach to immunotherapy against malignant gliomas. While previous vaccine efforts have focused exclusively on HLA class I-restricted peptides, class II-restricted peptides are necessary to induce CD4⁺ helper T cells and sustain effective anti-tumor immunity. In this report we investigated the ability of five candidate peptide epitopes derived from glioma-associated antigens MAGE and IL-13 receptor α2 to detect and characterize CD4⁺ helper T cell responses in the peripheral blood of patients with malignant gliomas.

Methods

Primary T cell responses were determined by stimulating freshly isolated PBMCs from patients with primary glioblastoma (GBM) (n = 8), recurrent GBM (n = 5), meningioma (n = 7), and healthy controls (n = 6) with each candidate peptide, as well as anti-CD3 monoclonal antibody (mAb) and an immunodominant peptide epitope derived from myelin basic protein (MBP) serving as positive and negative controls, respectively. ELISA was used to measure IFN-γ and IL-5 levels, and the ratio of IFN-γ/IL-5 was used to determine whether the response had a predominant Th1 or Th2 bias.

Results

We demonstrate that novel HLA Class-II restricted MAGE-A3 and IL-13Rα2 peptides can detect T cell responses in patients with GBMs as well as in healthy subjects. Stimulation with a variety of peptide antigens over-expressed by gliomas is associated with a profound reduction in the IFN-γ/IL-5 ratio in GBM patients relative to healthy subjects. This bias is more pronounced in patients with recurrent GBMs.

Conclusions

Therapeutic vaccine strategies to shift tumor antigen-specific T cell response to a more immunostimulatory Th1 bias may be needed for immunotherapeutic trials to be more successful clinically.

Traumatic brain injury in pediatric patients: evidence for the effectiveness of decompressive surgery

Traumatic brain injury (TBI) is the current leading cause of death in children over 1 year of age. Adequate management and care of pediatric patients is critical to ensure the best functional outcome in this population. In their controversial trial, Cooper et al. concluded that decompressive craniectomy following TBI did not improve clinical outcome of the analyzed adult population. While the study did not target pediatric populations, the results do raise important and timely clinical questions regarding the effectiveness of decompressive surgery in pediatric patients. There is still a paucity of evidence regarding the effectiveness of this therapy in a pediatric population, and there is an especially noticeable knowledge gap surrounding age-stratified interventions in pediatric trauma. The purposes of this review are to first explore the anatomical variations between pediatric and adult populations in the setting of TBI. Second, the authors assess how these differences between adult and pediatric populations could translate into differences in the impact of decompressive surgery following TBI.

Management of intracranial hemorrhage in a child with a left ventricular assist device

Pediatric patients bridged to heart transplant with LVADs require chronic anticoagulation and are at increased risk of hemorrhagic complications, including intracranial hemorrhage. In this population, intracranial hemorrhage is often fatal. We report a case of successful management of a five-yr-old-boy with DCM on an LVAD who developed a subdural hematoma. We initially chose medical management, weighing the patient's high risk of thromboembolism from anticoagulation reversal against the risk of his chronic subdural hematoma. When head CT showed expansion of the hemorrhage with increasing midline shift, we chose prompt surgical evacuation of the hematoma with partial reversal of anticoagulation, given the increased risk of acute deterioration. The patient ultimately received an orthotopic heart transplant and was discharged with no permanent neurological complications. This represents a case of a pediatric patient on an LVAD who survived a potentially fatal subdural hematoma and was successfully bridged to cardiac transplantation.

Internal cranial expansion surgery for the treatment of refractory idiopathic intracranial hypertension

OBJECT

Idiopathic intracranial hypertension (IIH) may be refractory to available medical and surgical therapies. Patients with this condition may suffer from intractable headaches, experience visual deterioration, or have other symptoms related to elevated intracranial pressure. Internal cranial expansion (ICE) is a novel surgical procedure that the authors have developed for the treatment of patients with this condition. Here, they describe ICE and present their initial experience in using this surgical procedure for the treatment of patients with refractory IIH.

METHODS

The authors conducted a retrospective review of 10 consecutive patients who underwent ICE for the treatment of IIH during a 5-year period. Preoperative and postoperative clinical parameters including patient symptoms, presence of papilledema, and available ICP or CSF opening pressures were compared. Procedural details and complications were noted. Intracranial volume increases were calculated using available pre- and postoperative CT scans.

RESULTS

Follow-up for the 10 patients in this series ranged from 1 to 39.6 months (mean 15.5 months). Technically successful ICE was performed in all patients within the cohort. Surgical complications included a single postoperative seizure in one patient and a sagittal sinus tear with no clinical sequelae in another patient. At the time of last follow-up, 7 (70%) of 10 patients were either symptomatically improved or asymptomatic. Six (67%) of 9 patients with preoperative headaches had reduction or resolution of this symptom, and all patients (4 of 4) with preoperative papilledema had a reduction in or complete resolution of this sign. Postoperative ICP or CSF opening pressures were normal in all patients (4 of 4) tested. Postoperative intracranial volume expansion ranged between 3.8% and 12%.

CONCLUSIONS

Internal cranial expansion is a safe and effective surgery for the treatment of patients with refractory IIH. This surgery expands the intracranial volume and thus promotes ICP normalization, which may lead to the reduction or complete resolution of the signs and symptoms of IIH. Internal cranial expansion may be used as part of a multidisciplinary management approach in the treatment of refractory IIH.

Pediatric considerations for pineal tumor management

Pineal tumors are relatively rare central nervous system lesions with a predilection for the pediatric population. For the vast majority of these lesions, surgical resection is a critical step in effective treatment. This article discusses current strategies for preoperative evaluation, operative management, and postoperative care of the pediatric patient with a newly diagnosed pineal region tumor.

Arteriovenous malformation-associated aneurysms in the pediatric population

OBJECT

Conventional cerebral angiography and treatment for ruptured arteriovenous malformations (AVMs) in children are often performed in a delayed fashion. In adults, current literature suggests that AVM-associated aneurysms may be more likely to hemorrhage than isolated AVMs, which often leads to earlier angiography and endovascular treatment of associated aneurysms. The nature of AVM-associated aneurysms in the pediatric population is virtually unknown. In this report, the authors investigate the relationship of associated aneurysms in a large group of children with AVMs.

METHODS

Seventy-seven pediatric patients (≤ 21 years old) with AVMs were treated at the Columbia University Medical Center between 1991 and 2010. Medical records and imaging studies were retrospectively reviewed, and associated aneurysms were classified as arterial, intranidal, or venous in location. Clinical presentation and outcome variables were compared between children with and without AVM-associated aneurysms.

RESULTS

A total of 30 AVM-associated aneurysms were found in 22 children (29% incidence). Eleven were arterial, 9 intranidal, and 10 were venous in location. There was no significant difference in the rate of hemorrhage (p = 0.91) between children with isolated AVMs (35 of 55 [64%]) and children with AVM-associated aneurysms (13 of 22 [59%]). However, of the 11 children with AVM-associated aneurysms in an arterial location, 10 presented with hemorrhage (91%). An association with hemorrhage was significant in univariate analysis (p = 0.045) but not in multivariate analysis (p = 0.37).

CONCLUSIONS

Associated aneurysms are present in nearly a third of children with AVMs, and when arterially located, are more likely to present with hemorrhage. These data suggest that early angiography with endovascular treatment of arterial-based aneurysms in children with AVMs may be indicated.

C1-2 instability from os odontoideum mimicking intramedullary spinal cord tumor

Os odontoideum is a common cause of atlantoaxial instability in the pediatric population. The authors present the cases of 2 patients whose initial clinical presentation and MR imaging findings were suggestive of an intramedullary neoplasm, but whose ultimate diagnosis was determined to be cervical spine instability and cord injury due to os odontoideum.