Systematic review and cumulative analysis of clinical properties of BRAF V600E mutations in PLNTY histological samples.

PURPOSE: Polymorphous low-grade neuroepithelial tumors of the young (PLNTY) represent a rare pediatric-type tumor that most commonly presents as medically refractory epilepsy. PLNTY has only recently been recognized as a distinct clinical entity, having been first described in 2016 and added to the World Health Organization classification of CNS tumors in 2021. Molecular studies have determined that PLNTY is uniformly driven by aberrant MAPK pathway activation, with most tumors carrying either a BRAF V600E mutation or activating FGFR2 or FGFR3 fusion protein. Although it is known that these driver mutations are mutually exclusive, little is known about differences in clinical presentation or treatment outcomes between PLNTY cases driven by these distinct mutations. METHODS: We performed a systematic review and cumulative analysis of PLNTY cases to assess whether or not PLNTY tumors carrying the BRAF V600E mutation exhibit different clinical behaviors. By searching the literature for all cases of PLNTY wherein BRAF V600E status was characterized, we compiled a dataset of 62 unique patient instances. Using a logistic regression-based approach, we assessed a primary outcome of what factors of a clinical presentation were associated with BRAF V600E mutations and a secondary outcome of what factors predicted total seizure freedom post-surgical resection. RESULTS: PLNTY cases carrying BRAF V600E mutations in the literature were strongly positively associated with adult patients (p = 0.0055, OR = 6.556; 95% Conf. Int. = 1.737-24.742). BRAF V600E status was also positively associated with tumor involvement of the temporal lobe (p = 0.0046, OR = 11.036; 95% Conf. Int. = 2.100-58.006). Male sex was also positively associated with BRAF V600E status, but the result did not quite achieve statistical significance (p = 0.0731). BRAF V600E status was not found to be associated with post-operative seizure freedom. CONCLUSIONS: These findings indicate that BRAF V600E-positive PLNTY exhibit characteristic clinical presentations but are not necessarily different in treatment responsiveness. Non-BRAF V600E tumors are more commonly associated with young patients.

Technical note: Traumatic atlanto-occipital dislocation and severe subaxial cervical distraction injury in an infant.

INTRODUCTION: Traumatic injuries of the spine requiring surgery are rare in infancy. Fusion procedures in the very young are not well-described at the atlanto-occipital junction or subaxial spine. Here we describe novel segmental posterior instrumentation in a severe spinal column disruption in an infant. CASE PRESENTATION: A 13-month-old male with atlanto-occipital dislocation and severe C6-7 distraction (ASIA impairment scale A) presented after a motor vehicle accident. He underwent instrumented fusion (occiput-C2 and C6-7) and halo placement. Postoperative imaging demonstrated reduction of the C6-7 vertebral bodies. Physical examination showed lower limb paraplegia and preserved upper extremity strength except for mild weakness in hand grip (3/5 on the MRC grading scale). Occiput-C2 instrumentation was performed using occipital keel and C2 pedicle screws with sublaminar C1 polyester tape. C6-7 reduction and fixation was performed with laminar hooks. Arthrodesis was promoted with lineage-committed cellular bone matrix allograft and suboccipital autograft. Anterior column stabilization was deferred secondary to a CSF leak. Intraoperative monitoring was performed throughout the procedure. Within 1 month after surgery the patient was able to manipulate objects against gravity. CT imaging revealed bony fusion and spontaneous reduction of C6-7. DISCUSSION: Spinal instrumentation is technically challenging in infants, regardless of injury mechanism, particularly in cases with complete spinal column disruption, but an anterior fusion may be avoided in infants and small children with posterior stabilization and halo placement.

Burr Hole Hemispherotomy-Modification of Trans-Sylvian Peri-Insular Technique: 2-Dimensional Operative Video.

Trans-sylvian peri-insular hemispherotomy represents a functional hemispherectomy with minimal brain removal used for treatment of refractory hemispheric epilepsy.1 Exposure for this procedure is achieved by craniotomy. Refinement in the hemispherotomy technique, including trends toward minimizing cortical resection, has contributed to a substantial drop in complication rates.2 We present a refinement of this technique, allowing for complete hemispheric disconnection through a single burr hole. In this instance, this technique was applied in the case of a 4-year-old girl who presented with medically refractory epilepsy, which had developed on the first day of life due to a perinatal incomplete left middle cerebral artery stroke. Postoperatively, the patient experienced no worsening of her preexisting right-sided hemiparesis and remains seizure-free 18 months postoperatively, now off medication. While the trans-sylvian peri-insular hemispherotomy represents an established surgical technique, this is the first report of this procedure performed in a minimally invasive fashion through a single burr hole. Beyond the minimal incision and small aperture in the skull, seldom appreciated nuances of hemispheric disconnection are described and demonstrated, including amygdala disconnection, hippocampal tail disconnection directly into splenium disconnection, concomitant intermediate disconnection and callosotomy, and frontobasal disconnection landmarks. Consent was obtained from the patient's parents for the surgical procedure, use of outcome videos, and for publication of this video and associated materials. The participants and patient's parents consented to publication of their images and that of the patient.

Isolated unilateral alar ligamentous injury: illustrative cases.

BACKGROUND: Isolated unilateral alar ligament injury (IUALI) is a rare and likely underreported occurrence after upper cervical trauma, with only 16 cases documented in the literature to date. Patients generally present with neck pain, and definitive diagnosis is typically made by magnetic resonance imaging (MRI). Unfortunately, likely due in part to its rarity, there are no formal guidelines for the treatment of an IUALI. Furthermore, there is a limited understanding of the long-term consequences associated with its inadequate treatment. OBSERVATIONS: Here, the authors report on three pediatric patients, each found to have an IUALI after significant trauma. All patients presented with neck tenderness, and two of the three had associated pain-limited range of neck motion. Imaging revealed either a laterally deviated odontoid process on cervical radiographs and/or MRI evidence of ligamentous strain or discontinuity. Each patient was placed in a hard cervical collar for 1 to 2 months with excellent resolution of symptoms. A comprehensive review of the literature showed that all patients with IUALI who had undergone external immobilization with either rigid cervical collar or halo fixation had favorable outcomes at follow-up. LESSONS: For patients with IUALI, a moderate course of nonsurgical management with rigid external immobilization appears to be an adequate first-line treatment.

Primary intraosseous xanthoma of the frontal bone in a child: illustrative case.

BACKGROUND: Skull lesions are a common finding in children, with dermoid cysts and eosinophilic granulomas observed most frequently. However, primary intraosseous xanthomas of the calvaria, which are lytic, expansile lesions that develop without underlying hyperlipidemic disease, are rare in children, with only one prior case reported. OBSERVATIONS: The authors describe the case of a healthy 6-year-old male who presented with a 2-month history of an enlarging midline skull mass that developed after a recent minor trauma. Imaging showed a full-thickness, lytic frontal bone lesion with an aggressive appearance and heterogeneous contrast enhancement. The patient underwent gross-total resection of the lesion with placement of a mesh cranioplasty. Histopathology revealed a primary intraosseous xanthoma. The patient was discharged on postoperative day 2 and required no further treatment at the 1-month follow-up. LESSONS: This is the first reported case of a primary intraosseous xanthoma in the frontal bone of a pediatric patient. It emphasizes the need to include primary xanthomas in the differential diagnosis for pediatric skull lesions, particularly when the lesion has an aggressive radiographic appearance or the patient has a history of focal trauma. Furthermore, our findings indicate that resection, together with subsequent monitoring for lesion reccurrence, is an adequate first-line treatment.

Use of a machine learning algorithm with a focus on spinopelvic parameters to predict development of symptomatic tethered cord after initial untethering surgery.

OBJECTIVE: Among patients with a history of prior lipomyelomeningocele repair, an association between increased lumbosacral angle (LSA) and cord retethering has been described. The authors sought to build a predictive algorithm to determine which complex tethered cord patients will develop the symptoms of spinal cord retethering after initial surgical repair with a focus on spinopelvic parameters. METHODS: An electronic medical record database was reviewed to identify patients with complex tethered cord (e.g., lipomyelomeningocele, lipomyeloschisis, myelocystocele) who underwent detethering before 12 months of age between January 1, 2008, and June 30, 2022. Descriptive statistics were used to characterize the patient population. The Caret package in R was used to develop a machine learning model that predicted symptom development by using spinopelvic parameters. RESULTS: A total of 72 patients were identified (28/72 [38.9%] were male). The most commonly observed dysraphism was lipomyelomeningocele (41/72 [56.9%]). The mean ± SD age at index MRI was 2.1 ± 2.2 months, at which time 87.5% of patients (63/72) were asymptomatic. The mean ± SD lumbar lordosis at the time of index MRI was 23.8° ± 11.1°, LSA was 36.5° ± 12.3°, sacral inclination was 30.4° ± 11.3°, and sacral slope was 23.0° ± 10.5°. Overall, 39.6% (25/63) of previously asymptomatic patients developed new symptoms during the mean ± SD follow-up period of 44.9 ± 47.2 months. In the recursive partitioning model, patients whose LSA increased at a rate ≥ 5.84°/year remained asymptomatic, whereas those with slower rates of LSA change experienced neurological decline (sensitivity 77.5%, specificity 84.9%, positive predictive value 88.9%, and negative predictive value 70.9%). CONCLUSIONS: This is the first study to build a machine learning algorithm to predict symptom development of spinal cord retethering after initial surgical repair. The authors found that, after initial surgery, patients who demonstrate a slower rate of LSA change per year may be at risk of developing neurological symptoms.

Intracranial complications secondary to acute bacterial sinusitis requiring neurosurgical intervention before and after the onset of the COVID-19 pandemic.

OBJECTIVE: Intracranial complications of acute bacterial sinusitis are rare pathologies that occur in children, and are associated with significant neurological morbidity and mortality. There is a subjective concern among neurosurgeons that the incidence of this rare disease has increased since the onset of the novel COVID-19 pandemic. The primary objective of this study was to review the presentation and management of patients admitted at the authors' institution with intracranial extension of sinusitis, to better understand the local disease burden relative to the COVID-19 pandemic. METHODS: This is a single-center retrospective observational cohort study. The patients underwent neurosurgical intervention for intracranial extension of sinusitis between January 1, 2007, and March 1, 2023. The historical cohort was defined as those patients who presented prior to March 2020. Clinical covariates such as surgical and microbiological data were collected and analyzed. RESULTS: A total of 78 patients (55 historical, 23 new) were included; they had a median age of 11.7 years and a male predominance of 69.2%. There was a significant increase in the annual rate of neurosurgical intervention for suppurative intracranial extension of acute bacterial sinusitis after the onset of the COVID-19 pandemic, with an average of 4.2 cases per year prior to March 2020 compared to 7.7 cases per year after that date (p = 0.013). This increase was largely driven by the unprecedented case volume of 13 cases in 2022. Patients in the new cohort were older (p = 0.009) and more likely to have Pott's puffy tumor/frontal bone osteomyelitis (p = 0.003) at the time of presentation than patients in the historical cohort. Patients in the new cohort had lower rates of readmission within 30 days of discharge than those in the historical cohort (p = 0.047). In both cohorts, patients with seizure on presentation were more likely to have neurological sequelae at last follow-up (p = 0.004), which occurred at a median of 2.9 months after discharge. CONCLUSIONS: Clinicians encountering pediatric patients presenting with persistent symptoms of acute bacterial sinusitis must have a high index of suspicion for suppurative intracranial extension. Prompt neuroimaging and subsequent neurosurgical intervention are critical to ensure timely diagnosis and treatment. The results in this study show a significant increase in the number of neurosurgical interventions for suppurative intracranial extension of sinusitis per year after the onset of the COVID-19 pandemic. Further research is needed to understand the underlying pathophysiology of this clinical phenomenon.