Atlantoaxial facet fixation using cervical facet cage: technical case report and review of the literature.

In 1994, the use of interfacet spacer placement was for joint distraction, reduction, and fusion to supplement atlantoaxial or occipitocervical fixation. Here, we present a unique case of bilateral atlantoaxial interfacet fixation using cervical facet cages (CFC) in a pediatric patient with basilar invagination. In addition, we review the literature on atlantoaxial facet fixation. We present a 12-year-old boy with Wiedemann-Steiner syndrome who presented with multiple episodes of sudden neck jerking, described as in response to a sensation of being shocked, and guarding against neck motion, found to have basilar invagination with cervicomedullary compression. He underwent an occiput to C3 fusion with C1-C2 CFC fixation. We also conducted a literature review identifying all publications using the following keywords: "C1" AND "C2" OR "atlantoaxial" AND "facet spacer" OR "DTRAX." The patient demonstrated postoperative radiographic reduction of his basilar invagination from 6.4 to 4.1 mm of superior displacement above the McRae line. There was a 4.5 mm decrease in the atlantodental interval secondary to decreased dens retroflexion. His postoperative course was complicated by worsening of his existing dysphagia but was otherwise unremarkable. His neck symptoms completely resolved. We illustrate the safe use of CFC for atlantoaxial facet distraction, reduction, and instrumented fixation in a pediatric patient with basilar invagination. Review of the literature demonstrates that numerous materials can be safely placed as a C1-C2 interfacet spacer including bone grafts, titanium spacers, and anterior cervical discectomy and fusion cages. We argue that CFC may be included in this arsenal even in pediatric patients.

Anterolateral keyhole transorbital routes to the skull base: a comparative anatomical study.

OBJECTIVE: Although keyhole transorbital approaches are gaining traction, their indications have not been adequately studied comparatively. In this study the authors have defined them also as transwing approaches-meaning that they use the different facies of the sphenoid wing for cranial entry-and sought to compare the four major ones: 1) lateral orbitocraniotomy through a lateral canthal incision (LatOrb); 2) modified orbitozygomatic approach through a palpebral incision (ModOzPalp); 3) modified orbitozygomatic approach through an eyebrow incision (ModOzEyB); and 4) supraorbital craniotomy through an eyebrow incision (SupraOrb), coupled with its expanded version (SupraTransOrb). METHODS: Cadaveric dissections were performed at the neuroanatomy lab. To delineate the skull base exposure, four formalin-fixed heads were used, with two sides dedicated to each approach. The outer limits were assessed via image guidance and were mapped and illustrated accordingly. A fifth head was dissected purely endoscopically, just to facilitate an overview of the transwing concept. Qualitative features were also rigorously examined. RESULTS: The LatOrb proves to be more versatile in the middle cranial fossa (MCF), whereas the anterior cranial fossa (ACF) exposure is limited to a small area above the sphenoid ridge. An anterior clinoidectomy is possible; however, the exposure of the roof of the optic canal is suboptimal. The ModOzPalp adequately exposes both the ACF and MCF. Its lateral trajectory allows the inferior to superior view, yet there is restricted access to the medial anterior skull base (olfactory groove). The ModOzEyB also provides extensive exposure of the ACF and MCF, but has a more superior to inferior trajectory compared to the ModOzPalp, making it more appropriate for pathology reaching the medial anterior skull base or even the contralateral side. The anterior clinoidectomy is performed with improved visualization of the optic canal. The SupraOrb provides mainly anterior cranial base exposure, with minimal middle fossa. An anterior clinoidectomy can be performed, but without any direct observation of the superior orbital fissure. Some MCF access can be accomplished if the lateral sphenoid wing is drilled inferiorly, leading to its highly versatile variant, the SupraTransOrb. CONCLUSIONS: All the aforementioned approaches use the sphenoid wing as skull base corridor from a specific orientation point; hence these are designated as transwing approaches. Their peculiarities mandate careful case selection for the effective and safe completion of the surgical goals.

Treatment of hydrocephalus following posterior fossa tumor resection: a multicenter collaboration from the Hydrocephalus Clinical Research Network.

OBJECTIVE: Persistent hydrocephalus following posterior fossa brain tumor (PFBT) resection is a common cause of morbidity in pediatric brain tumor patients, for which the optimal treatment is debated. The purpose of this study was to compare treatment outcomes between VPS and ETV in patients with persistent hydrocephalus following surgical resection of a PFBT. METHODS: A post-hoc analysis was performed of the Hydrocephalus Clinical Research Network (HCRN) prospective observational study evaluating VPS and ETV for pediatric patients. Children who experienced hydrocephalus secondary to PFBT from 2008 to 2021 were included. Primary outcomes were VPS/ETV treatment failure and time-to-failure (TTF). RESULTS: Among 241 patients, the VPS (183) and ETV (58) groups were similar in age, extent of tumor resection, and preoperative ETV Success Score. There was no difference in overall treatment failure between VPS and ETV (33.9% vs 31.0%, p = 0.751). However, mean TTF was shorter for ETV than VPS (0.45 years vs 1.30 years, p = 0.001). While major complication profiles were similar, compared to VPS, ETV patients had relatively higher incidence of minor CSF leak (10.3% vs. 1.1%, p = 0.003) and pseudomeningocele (12.1% vs 3.3%, p = 0.02). No ETV failures were identified beyond 3 years, while shunt failures occurred beyond 5 years. Shunt infections occurred in 5.5% of the VPS cohort. CONCLUSIONS: ETV and VPS offer similar overall success rates for PFBT-related postoperative hydrocephalus. ETV failure occurs earlier, while susceptibility to VPS failure persists beyond 5 years. Tumor histology and grade may be considered when selecting the optimal means of CSF diversion.

The Eyebrow Approach for the Management of Pediatric Frontal Epidural Abscesses Secondary to Diffuse Sinusitis.

BACKGROUND: Minimally invasive approaches to the anterior cranial fossa have evolved over the past few decades. The management of frontal epidural abscesses (EDAs) secondary to diffuse sinusitis in the pediatric population using minimally invasive techniques is scarcely reported in the literature. Herein, we report the utilization of a minimally invasive eyebrow approach for multidisciplinary concurrent evacuation of frontal EDA secondary to diffuse sinusitis and trephination of the frontal sinus in three pediatric patients. CASE REPORTS: Three pediatric patients presented to the emergency room with severe headaches, visual changes, somnolence, and significant facial and periorbital swelling. Imaging revealed diffuse sinusitis with focal frontal epidural extension. In all cases, progressive clinical deterioration along with the radiographic findings mandated urgent surgical intervention. The eyebrow approach allowed for concomitant evacuation of the frontal EDA and trephination of the frontal sinus followed by functional endoscopic sinus surgery in the same setting. All patients tolerated the procedure well with complete resolution of their symptoms at the completion of antibiotic therapy and complete resolution of the EDA. CONCLUSION: The eyebrow approach is a minimally invasive technique that should be considered as part of the armamentarium in the management of select EDA in the pediatric population. It allows for multidisciplinary collaboration between neurosurgeons and otolaryngologists for concomitant evacuation of the EDA and trephination of the frontal sinus. This approach is a feasible, safe, and effective minimally invasive technique that can be employed for the management of EDA secondary to diffuse sinusitis in the pediatric population.

Applications of Endoscopic Endonasal Surgery in Early Childhood: A Case Series.

INTRODUCTION: Endoscopic endonasal surgery (EES) has been slower to gain popularity in early childhood due to anatomical challenges. We sought to describe the safety and efficacy of EES in early childhood. METHODS: All patients younger than 7 years who underwent EES at a large Cranial Base Center from 2002 to 2019 were reviewed as a retrospective cohort study. RESULTS: Thirty-six patients underwent EES before the age of 7 years. Four patients had two-stage EES. Two patients required combined transcranial and endonasal approaches. The mean age at the time of initial surgery was 4 years (range: 1-6). Twenty patients were male, and 16 were female. Of 21 tumors intended for resection, 11 patients had gross total resections, and 10 had near total (>95% tumor removed) resections. Nine patients (43%) had recurrences, of which 6 were craniopharyngiomas (p = 0.01). There was no difference in recurrence rates based on the degree of resection (p = 0.67). Three cerebrospinal fluid (CSF) leaks occurred following primary EES (8%). Following an increase in nasoseptal flap usage (31-52%) and CSF diversion (15-39%) in 2008, there was only one CSF leak out of 23 patients (4 vs. 15%; p = 0.54). Postoperatively, 1 patient developed a permanent new cranial neuropathy, and 1 patient developed a permanent visual field cut. Six patients developed permanent postoperative panhypopituitarism, of which all were craniopharyngiomas (p < 0.001). The mean follow-up was 64 months. CONCLUSIONS: Early childhood EES is both safe and technically feasible for a variety of pathologies.

Comparison of Follow-Up Length-Matched Single-Center Myelomeningocele Postnatal Closure Cohort to the Management of Myelomeningocele Study (MOMS) Trial Results.

OBJECTIVE: We sought to compare our large single-institution cohort of postnatal myelomeningocele closure to the 2 arms of the Management of Myelomeningocele Study (MOMS) trial at the designated trial time points, as well as assess outcomes at long-term follow-up among our postnatal cohort. METHODS: A single-institutional retrospective review of myelomeningocele cases presenting from 1995 to 2015 at Children's Hospital of Pittsburgh was performed. We compared outcomes at 12 and 30 months to both arms of the MOMS trial and compared our cohort's outcomes at those designated time points to our long-term outcomes. Univariate statistical analysis was performed as appropriate. RESULTS: One-hundred sixty-three patients were included in this study. All patients had at least 2-year follow-up, with a mean follow-up of 10 years (range 2-20 years). There was no difference in the overall distribution of anatomic level of defect. Compared to our cohort, the prenatal cohort had a higher rate of tethering at 12 months of age, 8 versus 1.8%. Conversely, the Chiari II decompression rate was higher in our cohort (10.4 vs. 1.0%). At 30 months, the prenatal cohort had a higher rate of independent ambulation, but our cohort demonstrated the highest rate of ambulation with or without assistive devices among the 3 groups. When comparing our cohort at these early time points to our long-term follow-up data, our cohort's ambulatory function decreased from 84 to 66%, and the rate of detethering surgery increased almost 10-fold. CONCLUSIONS: This study demonstrated that overall ambulation and anatomic-functional level were significantly better among our large postnatal cohort, as well as having significantly fewer complications to both fetus and mother, when compared to the postnatal cohort of the MOMS trial. Our finding that ambulatory ability declined significantly with age in this patient population is worrisome for the long-term outcomes of the MOMS cohorts, especially given the high rates of cord tethering at early ages within the prenatal cohort. These findings suggest that the perceived benefits of prenatal closure over postnatal closure may not be as substantial as presented in the original trial, with the durability of results still remaining a concern.

Emerging indications for stereotactic laser interstitial thermal therapy in pediatric neurosurgery.

Surgical treatment of deep or difficult to access lesions represents a unique and significant challenge for pediatric neurosurgeons. The introduction of stereotactic magnetic resonance-guided laser interstitial thermal therapy (LITT) over the last decade has had a dramatic impact on the landscape of pediatric neurosurgery. LITT provides a safe and effective option for children with epilepsy from hypothalamic hamartoma that represents a ground-breaking new therapy for a condition which was historically very difficult to treat with previous neurosurgical techniques. LITT has also been used as an alternative surgical technique for mesial temporal sclerosis, focal cortical dysplasia, MR-negative epilepsy, cavernoma-related epilepsy, insular epilepsy, and corpus callosotomy among other epilepsy etiologies. In some cases, LITT has been associated with improved cognitive outcomes compared to standard techniques, as in mesial temporal lobe epilepsy. Initial experiences with LITT for neuro-oncologic processes are also promising. LITT is often attractive to patients and providers as a minimally invasive approach, but the differences in safety and clinical outcome between LITT and traditional approaches are still being studied. In this review, we examine the emerging indications and clinical evidence for LITT in pediatric neurosurgery.

Extensive tumor calcification in response to pre-operative reductive chemotherapy in pediatric esthesioneuroblastoma: a case report.

Esthesioneuroblastomas are uncommon tumors in pediatric patients and are typically treated with multimodal therapy. Changes in gross tumor quality and character in response to adjuvant treatment have not been clearly reported. We report the case of a 15-year-old female with a diagnosis of Kadish stage C esthesioneuroblastoma who was treated with neoadjuvant chemotherapy and surgical resection. The patient's tumor demonstrated cytoreduction after chemotherapy but also was found to have calcified. A combined trans-frontal sinus craniotomy with endoscopic endonasal resection was performed and resulted in negative margins and good clinical outcome.

Development and implementation of a novel child life protocol to enhance psychosocial support for pediatric awake craniotomies: technical note.

Awake craniotomies are a crucial tool for identifying eloquent cortex, but significant limitations frequently related to patient tolerance have limited their applicability in pediatric cases. The authors describe a comprehensive, longitudinal protocol developed in collaboration with a certified child life specialist (CCLS) in order to enhance patient experiences and develop resiliency related to the intraoperative portion of cases. This protocol includes preoperative conditioning, intraoperative support, and postoperative positive reinforcement and debriefing. A unique coping plan is developed for each prospective patient. With appropriate support, awake craniotomy may be applicable in a wider array of preadolescent and adolescent patients than has previously been possible. Future prospective studies are needed to validate this approach.

Early practices in endonasal skull base surgery during the COVID-19 pandemic: a global survey.

OBJECTIVE: During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, endoscopic endonasal surgery (EES) is feared to be a high-risk procedure for the transmission of coronavirus disease 2019 (COVID-19). Nonetheless, data are lacking regarding the management of EES during the pandemic. The object of this study was to understand current worldwide practices pertaining to EES for skull base/pituitary tumors during the SARS-CoV-2 pandemic and provide a basis for the formulation of guidelines. METHODS: The authors conducted a web-based survey of skull base surgeons worldwide. Different practices by geographic region and COVID-19 prevalence were analyzed. RESULTS: One hundred thirty-five unique responses were collected. Regarding the use of personal protective equipment (PPE), North America reported using more powered air-purifying respirators (PAPRs), and Asia and Europe reported using more standard precautions. North America and Europe resorted more to reverse transcriptase-polymerase chain reaction (RT-PCR) for screening asymptomatic patients. High-prevalence countries showed a higher use of PAPRs. The medium-prevalence group reported lower RT-PCR testing for symptomatic cases, and the high-prevalence group used it significantly more in asymptomatic cases.Nineteen respondents reported transmission of COVID-19 to healthcare personnel during EES, with a higher rate of transmission among countries classified as having a medium prevalence of COVID-19. These specific respondents (medium prevalence) also reported a lower use of airborne PPE. In the cases of healthcare transmission, the patient was reportedly asymptomatic 32% of the time. CONCLUSIONS: This survey gives an overview of EES practices during the SARS-CoV-2 pandemic. Intensified preoperative screening, even in asymptomatic patients, RT-PCR for all symptomatic cases, and an increased use of airborne PPE is associated with decreased reports of COVID-19 transmission during EES.

A Case Report of Pediatric Geniculate Neuralgia Treated with Sectioning of the Nervus Intermedius and Microvascular Decompression of Cranial Nerves IX and X.

BACKGROUND: Classic geniculate neuralgia (GN) is a rare condition characterized by lancinating pain centered in the ear and not involving the throat. To the best of our knowledge, no case of pediatric GN has been reported in the English literature. CASE PRESENTATION: We present the first reported case of successfully treated GN in a child via an endoscopic approach. The patient was a 9-year-old boy who presented with a 1-year history of lancinating right ear pain. Neuroleptics resulted in a short-lived improvement in symptoms, but with significant side effects. Extensive evaluation by multiple specialties did not reveal a cause for his pain. Imaging disclosed a tortuous loop of the right posterior inferior cerebellar artery abutting cranial nerves IX and X but no other abnormalities. The patient underwent an endoscopic microvascular decompression of cranial nerves IX and X, and sectioning of the nervus intermedius through a right retromastoid craniotomy. Postoperatively, the patient reported complete resolution of his symptoms that persisted at 3 months of follow-up. At the 5-year follow-up, the patient maintained pain relief and was developing normally. CONCLUSION: GN can affect the pediatric population. In carefully selected patients with consistent clinical and radiographic presentation, sectioning of the nervus intermedius and microvascular decompression of the lower cranial nerves can be an effective treatment.

Is Schimmelpenning Syndrome Associated with Intracranial Tumors? A Case Report.

Schimmelpenning syndrome is a rare, well-defined constellation of clinical phenotypes associated with the presence of nevus sebaceous and multisystem abnormalities most commonly manifested as cerebral, ocular, and skeletal defects [1]. A single nucleotide mutation in the HRAS or KRAS genes resulting in genetic mosaicism is responsible for the clinical manifestations of this syndrome in the majority of cases. We report a case of an adolescent boy with Schimmelpenning syndrome with a multifocal pilocytic astrocytoma. No HRAS or KRAS gene mutations were noted in the tumor on genetic sequencing. However, glial tumors have been associated with genetic mutations of RAS upregulation, which may imply a common pathway.

Intracranial Myxoid Mesenchymal Tumor with Rare EWSR1-CREM Translocation.

Translocations between EWSR1 and members of the CREB family of transcription factors (CREB1, ATF1, and CREM) are rare genetic findings occurring in various sarcomas. Of these, the EWSR1-CREM translocation is the most rarely reported. We present the case of a 9-year-old boy who presented with a year of fatigue, weight loss, and abulia. A brain MRI revealed a frontal interhemispheric tumor arising from the falx. After resection, pathology demonstrated a myxoid mesenchymal tumor with an EWSR1-CREM translocation. A series of recent reports of similar tumors has generated ongoing debate in the literature over the classification of these tumors either as intracranial angiomatoid fibrous histiocytomas, which also harbor EWSR1-CREB family translocations, or as a novel diagnostic entity. The present case provides another example of the rare EWSR1-CREM fusion in an intracranial myxoid mesenchymal tumor that recurred in just 6 months despite gross total resection. The findings are discussed in the context of the existing literature and the ongoing effort to appropriately classify this type of tumor.

Neurosurgical Resident Exposure to Pediatric Neurosurgery: An Analysis of Resident Case Logs.

INTRODUCTION: The purpose of this study is to identify the national trends of exposure to pediatric procedures during neurosurgical residency and to subsequently evaluate how neurosurgery residents' experiences correlate with the minimum requirements set forth by the American College of Graduate Medical Education (ACGME). METHODS: ACGME resident case logs from residents graduating between 2013 and 2017 were retrospectively reviewed. These reports were analyzed to determine trends in resident operative experience in pediatric procedures. The number of cases performed by residents was compared to the required minimums set by the ACGME within each pediatric surgical category. A linear regression analysis and t tests were utilized to analyze the change in cases performed over the study period. RESULTS: A mean of 98.8 procedures were performed for each of the 877 residents graduating between 2013 and 2017. The total number of pediatric procedures declined at a rate of 1.7 cases/year (r2 = 0.77, p = 0.05). Spine and cerebrospinal fluid diversion procedures showed decreasing trends at rates of 1.9 (r2 = 0.70, p = 0.08) and 1.2 (r2 = 0.70, p = 0.08) cases/year, respectively. The number of trauma and brain tumor cases were shown to have increasing rates at 1.0 (r2 = 0.86, p = 0.02) and 0.3 (r2 = 0.69, p = 0.08) cases/year, respectively, with trauma cases showing significant increases. There was also a trend of increasing cases logged as the lead resident surgeon by 12.9 cases/year (r2 = 0.99, p < 0.001). The number of cases performed by the average graduating resident was also significantly higher than the minimums required by the ACGME; residents, on average, performed 3 times the required minimum number of pediatric cases. CONCLUSION: Neurosurgical residents graduating from 2013 to 2017 reported significantly higher volumes of pediatric neurosurgery cases than the standards set for by the ACGME. During this time, there was also a significant trend of increasing cases logged as the lead resident surgeon, suggesting more involvement in the critical portions of pediatric cases. There was also a significant, but not clinically impactful, decrease in pediatric case volumes during this time. However, the overall data indicate that residents are continuing to gain valuable pediatric experience during residency training.

The Use of External Ventricular Drainage to Reduce the Frequency of Wound Complications in Myelomeningocele Closure.

INTRODUCTION: Myelomeningocele (MMC) is an open neural tube defect routinely surgically closed within 48 h of birth to prevent secondary infection. Up to 18% of patients experience wound complications, and 85% require shunting for hydrocephalus. We hypothesized that wound complications could be reduced by cerebrospinal fluid (CSF) diversion at the time of closure. METHODS: Institutional review board approval was obtained to review records of the 88 patients who underwent MMC closure between January 2005 and June 2016 at the Children's Hospital of Pittsburgh. Twenty-three patients (26%) had an external ventricular drain (EVD) placed at the time of MMC closure and underwent 7-11 days of CSF drainage. Fourteen patients (16%) had a shunt placed at the time of MMC closure, and 51 (58%) had no form of CSF diversion at the time of MMC closure. RESULTS: Patients with an EVD or shunt placed at the time of closure had no wound complications. In contrast, 8 patients (16%) without CSF diversion at closure developed wound complications (p = 0.048). Seven of the 8 wound complications occurred in the 71 patients with evidence of hydrocephalus at birth (p = 0.98). Of patients with evidence of hydrocephalus at the time of MMC closure, wound complications had a higher rate of occurrence among patients who did not receive a shunt or EVD at closure (p = 0.01). When comparing only patients with evidence of hydrocephalus at birth, the EVD group alone had a lower rate of wound complications than patients who did not receive CSF diversion at the time of closure (p = 0.031). CONCLUSIONS: These results suggest that addressing hydrocephalus at the time of MMC closure significantly reduces the likelihood of wound complications and may justify temporary CSF diversion at birth, at least in those patients manifesting hydrocephalus.

Absent pedicles in campomelic dysplasia.

OBJECTIVES: The objective of the present study is to report a case of campomelic dysplasia illustrating the absence of cervical and thoracic pedicles. This report reiterates the importance of this clinical peculiarity in the setting of spine instrumentation. MATERIALS AND METHODS: A 10-year-old female patient with campomelic dysplasia presented with progressive kyphoscoliosis and signs of neural compromise. Imaging studies confirmed thoracic level stenosis and demonstrated absence of multiple pedicles in cervical and thoracic spine. The patient underwent decompression and instrumentation/fusion for her spinal deformity. RESULTS: The patient was instrumented between C2 and L4 with pedicle screws and sublaminar cables. However, pedicle fixation was not possible for the lower cervical and upper-mid thoracic spine. Also, floating posterior elements precluded the use of laminar fixation in the lower cervical spine. Cervicothoracic lumbosacral orthosis (CTLSO) was used for external immobilization to supplement the tenuous fixation in the cervicothoracic area. The patient improved neurologically with no signs of implant failure at the 2-year follow-up. CONCLUSIONS: Absence of pedicles and floating posterior elements present a challenge during spine surgery in campomelic dysplasia. Surgeons should prepare for alternative fixation methods and external immobilization when planning on spinal instrumentation in affected patients. LEVEL OF EVIDENCE: Level IV Case Report.

Facial spasms, but not hemifacial spasm: a case report and review of literature.

INTRODUCTION: Facial spasms represent a complicated array of neurological motor disorders with unique diagnostic and treatment algorithms. Due to the rarity of many of these disorders in the pediatric population, special care must be taken in identifying subtle differences in presentation of these disorders. METHODS: We present a case of a 3-year-old boy diagnosed with a brainstem ganglioglioma, Chiari 1 malformation, and a 2-year history of left-sided facial spasms. Stereotyped facial contractions and subtle eye deviation occurred every 10 s, with downward movement rather than upward elevation of the eyebrow. RESULTS: MRI revealed absence of a clear compressive vessel of the centrally-myelinized portion of the facial nerve, and EMG of the left facial nerve demonstrated no abnormal motor response or evidence of "lateral spread." Given these findings, a diagnosis of hemifacial seizures was made. Microvascular decompression was not recommended, and botulinum toxin injection was not pursued; however, the patient has remained refractory to antiepileptic drugs, possibly due to biochemical alteration by his ganglioglioma. He may eventually require surgical debulking should his symptoms progress. CONCLUSION: Hemifacial spasm is a well-recognized disorder, but similar conditions can, at times, imitate its appearance. While our patient presented with facial spasms, his clinical history, examination, and radiographic and electrophysiological findings were more consistent with hemifacial seizures secondary to a brainstem lesion, rather than hemifacial spasms. It is important to distinguish the two entities, as misdiagnosis and inappropriate diagnostic or therapeutic measures may be taken inadvertently.

Shotgun pellet embolization to the posterior cerebral artery.

INTRODUCTION: Projectile embolization to the cerebral vasculature and is almost exclusively seen in the anterior circulation due to the greater diameter and flow of the internal carotid arteries. In children, this phenomenon is ever rarer. METHODS: We present a case of a 9-year-old boy who suffered from a shotgun blast to the thorax and abdomen. He was subsequently found to have a pellet that had presumably traveled from either the left ventricle or directly via the subclavian artery to the vertebrobasilar system to become lodged in the P3 segment of his posterior cerebral artery. RESULTS: The patient developed a small occipital infarct with a corresponding right superior quadrantanopsia. He was managed as an inpatient non-operatively with a heparin drip and was placed on long-term low-dose aspirin on discharge. The patient recovered well from his injury and remains neurologically stable 2 years after the initial injury. Interval imaging demonstrated that the pellet remains stable in its position. DISCUSSION: To our knowledge, this represents the first non-fatal missile embolus to the posterior cerebral artery in a pediatric patient. Patients with minimal symptoms may benefit from conservative management given the inherent risks of embolectomy.

Histopathological examination of spine tumors after treatment with radiosurgery.

OBJECTIVE Increased survival time after diagnosis of neoplastic disease has resulted in a gradual increase in spine tumor incidence. Radiosurgery is frequently a viable alternative to operative management in a population with severe medical comorbidities. The authors sought to assess the histopathological consequences of radiosurgery in the subset of patients progressing to operative intervention. METHODS Eighteen patients who underwent radiosurgery for spine tumors between 2008 and 2014 subsequently progressed to surgical treatment. A histopathological examination of these cases was performed. Indications for surgery included symptomatic compression fractures, radiographic instability, and symptoms of cord or cauda equina compression. Biopsy samples were obtained from the tumor within the radiosurgical zone in all cases and were permanently fixated. Viable tumor samples were stained for Ki 67. RESULTS Fifteen patients had metastatic lesions and 3 patients had neurofibromas. The mean patient age was 57 years. The operative indication was symptomatic compression in 10 cases (67%). The most frequent metastatic lesions were breast cancer (4 cases), renal cell carcinoma (3), prostate cancer (2), and endometrial cancer (2). In 9 (60%) of the 15 metastatic cases, histological examination of the lesions showed minimal evidence of inflammation. Viable tumor at the margins of the radiosurgery was seen in 9 (60%) of the metastatic cases. Necrosis in the tumor bed was frequent, as was fibrotic bone marrow. Vascular ectasia was seen in 2 of 15 metastatic cases, but sclerosis with ectasia was frequent. No evidence of malignant conversion was seen in the periphery of the lesions in the 3 neurofibroma cases. In 1 case of neurofibroma, the lesion demonstrated some small areas of remnant tumor in the radiosurgical target zone. CONCLUSIONS This case series demonstrates important histopathological characteristics of spinal lesions treated by SRS. Regions with the highest exposure to radiation appear to be densely necrotic and show little evidence of tumor growth, whereas peripheral regions distant from the radiation dosage are more likely to demonstrate viable tumor in malignant and benign neoplasms. Physiological tissue appears to be similarly affected. With additional investigation, a more homogenized field of hypofractionated radiation exposure may allow for tumor obliteration with relative preservation of critical anatomical structures.