Electroencephalographic Indices for Clinical Endpoints during Propofol Anesthesia in Infants: An Early-phase Propofol Biomarker-finding Study.

BACKGROUND: Unlike expired sevoflurane concentration, propofol lacks a biomarker for its brain effect site concentration, leading to dosing imprecision particularly in infants. Electroencephalography monitoring can serve as a biomarker for propofol effect site concentration, yet proprietary electroencephalography indices are not validated in infants. The authors evaluated spectral edge frequency (SEF95) as a propofol anesthesia biomarker in infants. It was hypothesized that the SEF95 targets will vary for different clinical stimuli and an inverse relationship existed between SEF95 and propofol plasma concentration. METHODS: This prospective study enrolled infants (3 to 12 months) to determine the SEF95 ranges for three clinical endpoints of anesthesia (consciousness-pacifier placement, pain-electrical nerve stimulation, and intubation-laryngoscopy) and correlation between SEF95 and propofol plasma concentration at steady state. Dixon's up-down method was used to determine target SEF95 for each clinical endpoint. Centered isotonic regression determined the dose-response function of SEF95 where 50% and 90% of infants (ED50 and ED90) did not respond to the clinical endpoint. Linear mixed-effect model determined the association of propofol plasma concentration and SEF95. RESULTS: Of 49 enrolled infants, 44 evaluable (90%) showed distinct SEF95 for endpoints: pacifier (ED50, 21.4 Hz; ED90, 19.3 Hz), electrical stimulation (ED50, 12.6 Hz; ED90, 10.4 Hz), and laryngoscopy (ED50, 8.5 Hz; ED90, 5.2 Hz). From propofol 0.5 to 6 µg/ml, a 1-Hz SEF95 increase was linearly correlated to a 0.24 (95% CI, 0.19 to 0.29; P < 0.001) µg/ml decrease in plasma propofol concentration (marginal R2 = 0.55). CONCLUSIONS: SEF95 can be a biomarker for propofol anesthesia depth in infants, potentially improving dosing accuracy and utilization of propofol anesthesia in this population.

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.

Long-term sequelae of normocephalic pansynostosis: a rare but insidious entity.

OBJECTIVE: Patients with normocephalic pansynostosis, who have a grossly normal head shape, are often overlooked early in life and present late with elevated intracranial pressure (ICP) requiring timely cranial vault expansion. This study evaluates the long-term clinical outcomes of patients with normocephalic pansynostosis. METHODS: We retrospectively reviewed patients with a clinical and radiographic diagnosis of primary pansynostosis who underwent vault reconstruction between 2000 and 2023. Clinical and treatment course after craniofacial interventions was followed in patients with normocephaly to assess outcomes. RESULTS: Thirty-five patients with primary pansynostosis were identified, of which eight (23.5%) had normocephaly and underwent initial vault expansion at a mean age of 5.0 ± 2.4 years. All eight patients (50.0% male) presented with symptoms of elevated ICP including headaches (50.0%), nausea and vomiting (50.0%), and developmental delay (62.5%) and/or signs of elevated ICP including papilledema (75.0%) and radiologic thumbprinting on head computed tomography scan (87.5%). Three of the four normocephalic patients who had over 7 years of postoperative follow-up developed subjective headaches, vision changes, or learning and behavioral issues in the long-term despite successful vault reconstruction. CONCLUSIONS: Our longitudinal experience with this rare but insidious entity demonstrates the importance of timely intervention and frequent postoperative monitoring, which are critical to limiting long-term neurological sequelae. Multidisciplinary care by craniofacial surgery, neurosurgery, ophthalmology, and neuropsychology with follow-up into adolescence are recommended to assess for possible recurrence of elevated ICP secondary to cranio-cerebral disproportion.

Vaulting further: cranial vault expansion for craniocerebral disproportion without primary craniosynostosis.

PURPOSE: Treatment of subjects with refractory idiopathic intracranial hypertension (IIH) or shunted hydrocephalus with chronic shunt complications is challenging. What is the role for cranial vault expansion, particularly utilizing posterior vault distraction osteogenesis (PVDO), in these cases? This study assesses medium-term efficacy of cranial vault expansion in this unique patient population. METHODS: A retrospective review was conducted of patients who underwent cranial vault expansion from 2008 to 2023 at the Children's Hospital of Philadelphia. Subjects who did not have a diagnosis of primary craniosynostosis were included in the study. Demographic information, medical history, and perioperative details were collected from medical records. Primary outcomes were the rate of CSF diversion procedures and resolution of presenting signs and symptoms. Secondary outcomes were perioperative and 90-day complications and reoperation requirement. RESULTS: Among 13 included subjects, nine (69.2%) patients had a primary diagnosis of shunted hydrocephalus and 4 (30.8%) patients had IIH. Twelve (92.3%) subjects underwent posterior vault distraction osteogenesis (PVDO) and one (7.7%) underwent posterior vault remodeling (PVR). All 4 patients with IIH demonstrated symptomatic improvement following PVDO, including resolution of headaches, vomiting, and/or papilledema. Among 9 patients with shunted hydrocephalus, CSF diversion requirement decreased from 2.7 ± 1.6 procedures per year preoperatively to 1.2 ± 1.8 per year following cranial vault expansion (p = 0.030). The mean postoperative follow-up was 4.1 ± 2.1 years and four (30.8%) patients experienced complications within 90 days of surgery, including infection (n = 2), CSF leak (n = 1), and elevated ICP requiring lumbar puncture (n = 1). Four (30.8%) patients underwent repeat cranial vault expansion for recurrence of ICP-related symptoms. At most recent follow-up, 7 of 9 patients with shunted hydrocephalus demonstrated symptomatic improvement. CONCLUSION: Cranial vault expansion reduced intracranial hypertension-related symptomology as well as the rate of CSF diversion-related procedures in patients with refractory IIH and shunted hydrocephalus without craniosynostosis, and should be considered in those who have significant shunt morbidity.

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.

Current Practice: Rationale for Screening Children with Hereditary Hemorrhagic Telangiectasia for Brain Vascular Malformations.

BACKGROUND: Hereditary hemorrhagic telangiectasia is an autosomal dominant vascular dysplasia characterized by mucocutaneous telangiectasias, recurrent epistaxis, and organ vascular malformations including in the brain, which occur in about 10% of patients. These brain vascular malformations include high-flow AVMs and AVFs as well as low-flow capillary malformations. High-flow lesions can rupture, causing neurologic morbidity and mortality. STATE OF PRACTICE: International guidelines for the diagnosis and management of hereditary hemorrhagic telangiectasia recommend screening children for brain vascular malformations with contrast enhanced MR imaging at hereditary hemorrhagic telangiectasia diagnosis. Screening has not been uniformly adopted by some practitioners who contend that screening is not justified. Arguments against screening include application of short-term data from the adult A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) trial of unruptured sporadic brain AVMs to children with hereditary hemorrhagic telangiectasia as well as concerns about administration of sedation or IV contrast and causing patients or families increased anxiety. ANALYSIS: In this article, a multidisciplinary group of experts on hereditary hemorrhagic telangiectasia reviewed data that support screening guidelines and counter arguments against screening. Children with hereditary hemorrhagic telangiectasia have a preponderance of high-flow lesions including AVFs, which have the highest rupture risk. The rupture risk among children is estimated at about 0.7% per lesion per year and is additive across lesions and during a lifetime. ARUBA, an adult clinical trial of expectant medical management versus treatment of unruptured brain AVMs, favored medical management at 5 years but is not applicable to pediatric patients with hereditary hemorrhagic telangiectasia given the life expectancy of a child. Additionally, interventional, radiosurgical, and surgical techniques have improved with time. Experienced neurovascular experts can prospectively determine the best treatment for each child on the basis of local resources. The "watch and wait" approach to imaging means that children with brain vascular malformations will not be identified until a potentially life-threatening and deficit-producing intracerebral hemorrhage occurs. This expert group does not deem this to be an acceptable trade-off.

Near-infrared spectroscopy monitoring in severe pediatric abusive head trauma.

OBJECTIVE: Abusive head trauma (AHT) is one of the most devastating forms of pediatric traumatic brain injury (TBI). It commonly presents with seizures, which may contribute to poor neurological outcome following trauma. Noninvasive near-infrared spectroscopy (NIRS) neuromonitoring may provide information on cerebral oxygenation and perfusion. In this study, the authors evaluated whether NIRS regional cerebral oxygen saturation (rSO2) values were associated with seizure activity confirmed by electroencephalography (EEG) and whether NIRS neuromonitoring could aid in seizure detection in patients with severe AHT. METHODS: The authors retrospectively analyzed pediatric patients aged ≤ 18 years who were admitted to a quaternary urban pediatric hospital from 2016 to 2022 with severe AHT, who received NIRS and EEG monitoring during their hospital course. They evaluated clinical presentation and hospital course, including imaging findings, EEG findings, and NIRS rSO2 values. RESULTS: Nineteen patients with severe AHT were monitored with both EEG and NIRS. The median age was 3.4 months, and 14 patients experienced seizures confirmed by EEG. On average, rSO2 values before, during, and after seizure did not differ significantly. However, within individual patients, bilateral regional NIRS rSO2 (bilateral forehead region) was seen to rise in the hour preceding seizure activity and during periods of frequent seizure activity, confirmed by EEG in the bilateral frontal-midline brain regions. CONCLUSIONS: To the best of the authors' knowledge, this is the largest study to analyze NIRS and seizures confirmed by EEG in the severe AHT population. The relationship between NIRS values and seizures in this series of pediatric patients with severe AHT suggests that, overall, regional NIRS cannot predict early seizures. However, increased cerebral oxygenation preceding seizure activity and during seizure activity may be detected by regional NIRS in certain patients with local seizure activity. Future studies with larger sample sizes may help elucidate the relationship between seizures and cerebral oxygenation in different regions in severe pediatric AHT.

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.

Indications for cerebral revascularization for moyamoya syndrome in pediatric sickle cell disease determined by Delphi methodology.

OBJECTIVE: Cerebral revascularization surgery (CRS) has been used to prevent stroke in children with sickle cell disease (SCD) and cerebral vasculopathy (e.g., moyamoya syndrome). While results suggest that it may be an effective treatment, surgical indications have not been well defined. This study sought to determine indications for offering revascularization surgery in centers with established sickle cell programs in the US. METHODS: Three sequential surveys utilizing the Delphi methodology were administered to neurosurgeons participating in the Stroke in Sickle Cell Revascularization Surgery study. Respondents were presented with clinical scenarios of patients with SCD and varying degrees of ischemic presentation and vasculopathy, and the group's agreement to offer surgical revascularization was measured. Consensus was defined as ≥ 75% similar responses. RESULTS: The response rate to all 3 surveys was 100%. Seventeen neurosurgeons from 16 different centers participated. The presence of moyamoya collaterals (MMCs) and arterial stenosis matching an ischemic distribution yielded the strongest recommendations to offer surgery. There was consensus to offer revascularization in the presence of MMCs and at least 50% arterial stenosis matching an ischemic distribution. In contrast, there was no consensus to offer revascularization with 50%-70% stenosis not matching an ischemic presentation in the absence of MMCs. The presence of the ivy sign in the distribution of the stenotic artery also contributed to the consensus to offer surgery in certain scenarios. CONCLUSIONS: There were several clinical scenarios that attained consensus to offer surgery; the strongest was moderate to severe arterial stenosis that matched the distribution of ischemic presentation in the presence of MMCs. Radiological findings of decreased cerebral flow or perfusion also facilitated attaining consensus to offer surgery. The findings of this study reflect expert opinion about questions that deserve prospective clinical research. Determination of indications for CRS can guide clinical practice and aid the design of prospective studies.