Undiagnosed sagittal synostosis as cause of "idiopathic" intracranial hypertension.

PURPOSE: Idiopathic intracranial hypertension (IIH) is a rare condition in children, but if diagnosed needs to be promptly treated to avoid clinical sequalae. The main purpose of this paper was to test our clinical experience with a cohort of normocephalic children with craniosynostosis who do not present in the routine way to craniofacial services, due to the normal head shape and age, diagnosed with IIH. METHODS: We retrospectively reviewed all children who were referred to neurosurgery from 2012 to 2022 for management of IIH on our prospectively kept database. We determined what treatments were offered and if there was an associated craniosynostosis. RESULTS: In total, 19 children were identified with an average age at referral of 11.5 years (st dev 4.0 years) with 11 male and 8 female. The most common presenting symptoms and signs were papilloedema (18/19), headaches (15/19), visual deterioration (9/19), nausea and vomiting (7/19) and diplopia (4/19). Five out of 19 children (26.3%) had a sagittal suture fused that was not identified at the time of treatment and all children were normocephalic. CONCLUSION: There is a cohort of children with IIH who will have concomitant craniosynostosis and ideally would benefit from cranial vault expansion as primary surgery rather than cerebrospinal fluid (CSF) diversion. We suggest all children with IIH requiring neurosurgical intervention have cross-sectional imaging to look for occult craniosynostosis prior to intervention.

A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host.

The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300-10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated-traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star.

Chiari Malformation Type 1 in Adults.

The term Chiari malformation refers to a heterogeneous group of anatomical abnormalities at the craniovertebral junction. Chiari malformation type 1 (CM1) refers to the abnormal protrusion of cerebellar tonsils through the foramen magnum and is by far the commonest type. Its prevalence is estimated approximately 1%; it is more common in women and is associated with syringomyelia in 25-70% of cases. The prevalent pathophysiological theory proposes a morphological mismatch between a small posterior cranial fossa and a normally developed hindbrain that results in ectopia of the tonsils.In most people, CM1 is asymptomatic and diagnosed incidentally. In symptomatic cases, headache is the cardinal symptom. The typical headache is induced by Valsalva-like maneuvers. Many of the other symptoms are nonspecific, and in the absence of syringomyelia, the natural history is benign. Syringomyelia manifests with spinal cord dysfunction of varying severity. The approach to patients with CM1 should be multidisciplinary, and the first step in the management is phenotyping the symptoms, because they may be due to other pathologies, like a primary headache syndrome. Magnetic resonance imaging, which shows cerebellar tonsillar decent 5 mm or more below the foramen magnum, is the gold standard investigative modality. The diagnostic workup may include dynamic imaging of the craniocervical junction and intracranial pressure monitoring.The management of CM1 is variable and sometimes controversial. Surgery is usually reserved for patients with disabling headaches or neurological deficits from the syrinx. Surgical decompression of the craniocervical junction is the most widely used procedure. Several surgical techniques have been proposed, but there is no consensus on the best treatment strategy, mainly due to lack of high-quality evidence. The management of the condition during pregnancy, restriction to lifestyle related to athletic activities, and the coexistence of hypermobility require special considerations.

Endoscopic third ventriculostomy for hydrocephalus after craniovertebral decompression for Chiari malformation type I: technical nuances and surgical pitfalls.

PURPOSE: Hydrocephalus after craniovertebral decompression (CVD) for Chiari I malformation (CM-1) is a well-recognised complication. The mainstay of management involves medical management with high-dose steroids and/or acetazolamide, repeated lumbar punctures, external ventricular drainage (EVD) or insertion of a ventriculoperitoneal shunt (VPS). Endoscopic third ventriculostomy (ETV) has only been used a handful of times to treat this type of hydrocephalus with controversial outcomes. Not much is known about this or the technical nuances of this procedure. We report our experience. METHODS: All children who underwent ETV to treat hydrocephalus post CVD done for CM-1 were identified from a prospectively kept database. RESULTS: Three children were identified (13F, 11F, 13F). The average time to presentation of hydrocephalus was 8 days after craniovertebral decompression. Two were successfully treated with ETV with brain imaging showing a reduction in the size of the ventricles post-operatively and not requiring any further cerebrospinal fluid drainage. In one patient, the procedure had to be abandoned after the peel away catheter was introduced into the right ventricle because CSF egressed under high pressure with ventricle walls collapse resulting in an obstructed view. This child ultimately required a VPS. CONCLUSION: ETV can be used to successfully treat post CVD hydrocephalus in CM-1 patients depending on the aetiology of the hydrocephalus. There are technical and anatomical commonalities between these cases which make it more challenging than an ETV performed in "typical" obstructive hydrocephalus. We describe our experience and review the cases previously reported in the literature.

Clinical features and outcome in pediatric arteriovenous malformation: institutional multimodality treatment.

PURPOSE: Intracranial arteriovenous-malformation (AVM) is a relatively rare condition in pediatrics, yet is a major cause of spontaneous intracranial hemorrhage with a risk of fatal hemorrhage reported to be between 4 and 29%. Little is known about vessel morphology and optimum treatment modalities including multimodality combination therapy and prognosis in children. METHODS: A retrospective review of all children presenting to our institution from 2006 to 2020 that had an AVM was undertaken. RESULTS: A total of 50 children were identified with median age of 11 (range 1-16) years. The mean follow-up was 7.6 years. Forty-one children presented as an emergency and of those, 40 had hemorrhage identified on initial brain imaging. The average nidus size was 25 mm, drainage was superficial in 51% of cases, and located in eloquent cortex in 56%. The supplemental Spetzler-Martin grading indicated 78% (39/50) were grade 4 and above (moderate to high risk). Primary treatment modalities included embolization in 50% (25) or SRS in 30% (15) and surgery in 20% (10).The AVM was obliterated on follow-up DSA in 66% children. Three children had post-treatment hemorrhage, two related to embolization and one the day following SRS, giving a re-bleed rate of 6%. The GOSE was available for 32 children at long term follow and 94% had a good outcome (GOSE 5-8). Two children died due to acute hemorrhage (4%). CONCLUSION: The majority of children with AVM present with hemorrhage. The rebleed rate during definitive treatment is low at 6% over the study period. The selective use of the 3 modalities of treatment has significantly reduced mortality and severe disability.

Regression of a spinal schwannoma after Pomalidomide.

A 77-year old female with a history of neurofibromatosis type 2 (NF2) was diagnosed with a spinal schwannoma that was managed conservatively over a decade. During this time, follow up imaging revealed this lesion had been growing and the patient had become symptomatic from it necessitating surgical decompression. However, the patient had been diagnosed with multiple myeloma and underwent treatment with Pomalidomide chemotherapy which delayed surgery for the spinal schwannoma. Further imaging of the spine revealed significant regression in the size of the spinal schwannoma. This phenomenon has not previously been reported and this report aims to explore the implications of Pomalidomide in patients with NF2 related spinal schwannomas.

Deep brain stimulation for refractory obsessive-compulsive disorder (OCD): emerging or established therapy?

A consensus has yet to emerge whether deep brain stimulation (DBS) for treatment-refractory obsessive-compulsive disorder (OCD) can be considered an established therapy. In 2014, the World Society for Stereotactic and Functional Neurosurgery (WSSFN) published consensus guidelines stating that a therapy becomes established when "at least two blinded randomized controlled clinical trials from two different groups of researchers are published, both reporting an acceptable risk-benefit ratio, at least comparable with other existing therapies. The clinical trials should be on the same brain area for the same psychiatric indication." The authors have now compiled the available evidence to make a clear statement on whether DBS for OCD is established therapy. Two blinded randomized controlled trials have been published, one with level I evidence (Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score improved 37% during stimulation on), the other with level II evidence (25% improvement). A clinical cohort study (N = 70) showed 40% Y-BOCS score improvement during DBS, and a prospective international multi-center study 42% improvement (N = 30). The WSSFN states that electrical stimulation for otherwise treatment refractory OCD using a multipolar electrode implanted in the ventral anterior capsule region (including bed nucleus of stria terminalis and nucleus accumbens) remains investigational. It represents an emerging, but not yet established therapy. A multidisciplinary team involving psychiatrists and neurosurgeons is a prerequisite for such therapy, and the future of surgical treatment of psychiatric patients remains in the realm of the psychiatrist.

Case report: Development of syringomyelia after anatomically successful craniovertebral decompression for Chiari I malformation without syrinx.

An 18 year old female with headaches and radiologically confirmed Chiari I malformation, without syringomyelia, underwent an anatomically and clinically successful craniovertebral decompression. Five years later she returned with extensive syringomyelia. This was treated successfully by division of an arachnoid web at the foramen of Magendie.

On day admissions in neurosurgery: a comparative cohort study.

Day of admission neurosurgery is a viable method to reduce health care associated costs, complications and length of stay. Within the national health service in England the picture is very mixed with some neurosurgery centres universally admitting patients the day before and others admitting on the day of surgery.We altered our admissions policy during a 4 month time period from 'day-before' surgery to 'day-of' surgery for elective neurosurgery. A number of patients still continued to be admitted the day before surgery due to consultant choice. We conducted a comparative cohort study of these two patient groups to see if there were any differences in surgical cancellation rates, the reasons for these cancellations and the implied cost savings.In total 199 patients underwent neurosurgery during this time period, 87 patients were admitted on the 'day-of' and 112 patients on the 'day-before' surgery. The overall cancellation rate was 18%. The cancellation rate in patients admitted on the 'day-of' surgery was 12.6% (11/87). The rate of cancellation in patients admitted the 'day-before' surgery was 22.3% (25/112). This difference was not significant (p = 0.1). Day of surgery admission resulted in a cost saving of almost £30,000 in this group of patients over a 4 month period. If extrapolated for all patients over the course of a year it would result in cost savings in the region of £150,000.In summary, admitting elective neurosurgery patients on the day of surgery does not affect cancellation rates, prevents unnecessary overnight hospital admission and results in significant cost saving.

Symptom outcome after craniovertebral decompression for Chiari type 1 malformation without syringomyelia.

BACKGROUND: Specific symptom outcomes after craniovertebral decompression for patients with Chiari type 1 malformation, without accompanying syringomyelia, are not well characterised and poorly reported. METHODS: We performed a retrospective review of all patients diagnosed with Chiari type 1, without syringomyelia, who underwent craniovertebral decompression in our unit. RESULTS: We identified 129 individuals with a minimum of 2 years' follow-up. The most common pre-operative symptoms were pressure dissociation headaches (78%), visual disturbances (33%), dizziness/balance disturbances (24%) and blackouts (17%). The symptoms most likely to respond to surgery included Valsalva-induced headache (74% response, p < 0.0001) and blackouts (86% response, p < 0.001). CONCLUSIONS: After successful craniovertebral decompression, most patients presenting with pressure dissociation headaches and blackouts will improve. However, the large variety of other symptoms patients often present with may not improve after surgery.

An observational correlation between stellar brightness variations and surface gravity.

Surface gravity is a basic stellar property, but it is difficult to measure accurately, with typical uncertainties of 25 to 50 per cent if measured spectroscopically and 90 to 150 per cent if measured photometrically. Asteroseismology measures gravity with an uncertainty of about 2 per cent but is restricted to relatively small samples of bright stars, most of which are giants. The availability of high-precision measurements of brightness variations for more than 150,000 stars provides an opportunity to investigate whether the variations can be used to determine surface gravities. The Fourier power of granulation on a star's surface correlates physically with surface gravity: if brightness variations on timescales of hours arise from granulation, then such variations should correlate with surface gravity. Here we report an analysis of archival data that reveals an observational correlation between surface gravity and root mean squared brightness variations on timescales of less than eight hours for stars with temperatures of 4,500 to 6,750 kelvin, log surface gravities of 2.5 to 4.5 (cgs units) and overall brightness variations of less than three parts per thousand. A straightforward observation of optical brightness variations therefore allows a determination of the surface gravity with a precision of better than 25 per cent for inactive Sun-like stars at main-sequence to giant stages of evolution.

A Critical Appraisal of a University's Response to a Campus Mass Shooting: Perspectives from Public Health Students and Researchers at Michigan State University.

Mass shootings are a public health crisis and have become more frequent on U.S. university campuses over the past decade, with the number doubling since 2000. Due to this alarming trend, many institutions have developed response strategies for active shooting events. Yet, the extent to which these response strategies address the needs and minimize harm for students, faculty, and staff has not been evaluated critically after a campus mass shooting. Michigan State University (MSU) experienced a mass shooting on February 13, 2023. Before, during, and 6 months following this tragedy, the university employed an estimated 18 strategies to inform, support, and protect its students, faculty, and staff. While MSU continues to address concerns and roll out programs related to this event, here we aimed to (1) create a timeline of resources and communication provided by MSU from the event to 6 months post-event; (2) critically evaluate the extent to which these resources met the needs of students, faculty, and staff through a survey among persons involved in public health research; and (3) identify potential areas for improvement in the university's responses. We used an online survey where participants (n = 10) rated the university responses and provided additional comments. From our survey, we recommend that, in the event of a campus shooting, other universities are attentive to re-engaging with the community within which the university is situated, holding communal events on campus, offering pauses in classes, and enhancing mental health services. These responses were seen as crucial to re-establish campus life and learning.

The risk of hardware infection in deep brain stimulation surgery is greater at impulse generator replacement than at the primary procedure.

BACKGROUND/AIMS: Infection of implanted hardware after deep brain stimulation (DBS) has a significant impact on patient morbidity. We examined all patients who underwent DBS procedures over the last 9 years in our centre to assess the infection rate and possible factors related to surgery that may predispose to infection. METHODS: Surgical reports and clinical notes were reviewed in 273 consecutive patients who underwent a total of 519 DBS-related procedures in our institute between November 2002 and September 2011. RESULTS: Sixteen separate hardware-related infections occurred in 11 patients. Infections occurred in 3% of all procedures and 4% of all patients. The infection rate after implantable pulse generator (IPG) replacement surgery was more than three times higher than after de novo DBS surgery. In addition, male patients were more likely to develop device-related infections. CONCLUSIONS: It is unclear why infection rates should be more than three times higher after IPG replacement surgery than after the de novo procedure. The former is a shorter and simpler procedure to conduct. Perhaps the use of better antimicrobial protection and rechargeable batteries may be useful strategies to reduce infections following IPG revision surgery.

Spectral Tuning of a Nanoparticle-on-Mirror System by Graphene Doping and Gap Control with Nitric Acid.

Nanoparticle-on-mirror systems are a stable, robust, and reproducible method of squeezing light into sub-nanometer volumes. Graphene is a particularly interesting material to use as a spacer in such systems as it is the thinnest possible 2D material and can be doped both chemically and electrically to modulate the plasmonic modes. We investigate a simple nanoparticle-on-mirror system, consisting of a Au nanosphere on top of an Au mirror, separated by a monolayer of graphene. With this system, we demonstrate, with both experiments and numerical simulations, how the doping of the graphene and the control of the gap size can be controlled to tune the plasmonic response of the coupled nanosphere using nitric acid. The coupling of the Au nanosphere and Au thin film reveals multipolar modes which can be tuned by adjusting the gap size or doping an intermediate graphene monolayer. At high doping levels, the interaction between the charge-transfer plasmon and gap plasmon leads to splitting of the plasmon energies. The study provides evidence for the unification of theories proposed by previous works investigating similar systems.

Rathke's Cleft Cyst Abscess with a Very Unusual Course.

Infected Rathke's cleft cysts (RCC) are extremely rare with only a few published cases. We report the case of a 31-year-old man who presented with headaches, visual disturbance, and hypopituitarism secondary to an infected RCC with extension of abscesses along the optic tract. Magnetic resonance imaging showed ring enhancing cystic lesions within an expanded sella with suprasellar and intraparenchymal extension. The radiological appearance suggested a high-grade optic glioma, but an endoscopic transsphenoidal biopsy revealed frank pus in the pituitary fossa, which subsequently grew Staphylococcus aureus . Pathological examination of the cyst wall showed an inflamed RCC. Following a prolonged course of intravenous antibiotics, the infection resolved and vision improved. RCC abscesses are rare and the intracranial extension of the infection in our case makes it unique.

Functional hemispherotomy for epilepsy in the very young.

OBJECTIVE: Epilepsy is one of the most common neurological disorders in children. Among very young children, one-third are resistant to medical treatment, and lack of effective treatment may result in adverse outcomes. Although functional hemispherotomy is an established treatment for epilepsy, its outcome in the very young child has not been widely reported. In this study the authors investigated seizure and developmental results after hemispherotomy in children younger than 3 years. METHODS: The authors reviewed a prospective database of all children younger than 3 years with medically intractable epilepsy who underwent functional hemispherotomy at the authors' institution during the period between 2012 and 2020. Demographic data, epilepsy history, underlying etiology, operative and transfusion details, and seizure and developmental outcomes were analyzed. RESULTS: Twelve patients were included in this study. The mean age (± SD) at seizure onset was 3 ± 2.6 months and at surgery was 1.3 ± 0.77 years, with a mean follow-up of 4 years. Diagnoses included hemimegalencephaly (n = 5), hemidysplasia (n = 2), hypoxic/hemorrhagic (n = 2), traumatic (n = 1), Sturge-Weber syndrome (n = 1), and mild hemispheric structural abnormality with EEG/PET correlates (n = 1). Eleven patients achieved an Engel class I outcome, and 1 patient achieved Engel class IV at last follow-up. No deaths, infections, cerebrovascular events, or unexpected long-term neurological deficits were recorded. All children progressed neurodevelopmentally following surgery, but their developmental levels remained behind their chronological age, with an overall mean composite Vineland Adaptive Behavior Scale score of 58 (normal: 86-114, low: < 70). One patient required insertion of a subdural peritoneal shunt, 1 patient required dural repair for a CSF fluid leak, and 1 patient required aspiration of a pseudomeningocele. In 2 patients, both of whom weighed less than 5.7 kg, the first operation was incomplete due to blood loss. CONCLUSIONS: Hemispherotomy in children younger than 3 years offers excellent seizure control and an acceptable risk-to-benefit ratio in well-selected patients. Families of children weighing less than 6 kg should be counseled regarding the possibility of staged surgery. Postoperatively, children continue to make appropriate, despite delayed, developmental progress.

Spontaneous resolution of a Chiari malformation with syringomyelia.

The Chiari I malformation (CM-I) is characterised by overcrowding of the posterior fossa and descent of the cerebellar tonsils and is associated with syringomyelia. With the increasing availability of magnetic resonance imaging, CM-I is placing a growing burden on neurosurgical services. However, its natural history remains poorly understood, and the timing and nature of surgical intervention is controversial. We present a case of a significant, symptomatic CM-I with associated syrinx which underwent complete spontaneous resolution over a 4-year period. Spontaneous regression of Chiari malformation and syringomyelia is exceedingly rare; a literature review reveals 15 other cases and only one case which underwent complete resolution. The present case and literature review suggest a more benign natural history of CM-I and support a more conservative approach to its management. Further studies are required to determine whether any factors can predict resolution for certain patient cohorts.

Seizure Outcome After Surgery for Insular High-Grade Glioma.

BACKGROUND: The insular cortex is an eloquent island of mesocortex surrounded by vital structures making this region relatively challenging to neurosurgeons. Historically, lesions in this region were considered too high risk to approach given the strong chance of poor surgical outcome. Advances in recent decades have meant that surgeons can more safely access this eloquent region. Seizure outcome after excision of insular low-grade gliomas is well reported, but little is known about seizure outcomes after excision of insular high-grade gliomas. METHODS: A retrospective analysis was performed of all patients presenting with new-onset seizures during 2015-2019 who underwent excision of an insular high-grade glioma at 3 regional neurosurgical centers in the United Kingdom. RESULTS: We identified 38 patients with a mean (SD) age of 45.7 (15.3) years with median follow-up of 21 months. At long-term follow-up, of 38 patients, 23 were seizure-free (Engel class I), 2 had improved seizures (Engel class II), 6 had poor seizure control (Engel class III/IV), and 7 died. CONCLUSIONS: Excision of insular high-grade gliomas is safe and results in excellent postoperative seizure control.

Geospatial-temporal analysis of the impact of ozone on asthma rescue inhaler use.

RATIONALE: Asthma is one of the most common chronic respiratory diseases in the United States. Several outdoor air pollutants have been associated with asthma morbidity. Previous studies of the effects of short-term air pollution exposure have been limited by potential exposure misclassification and limited spatial and temporal resolution of asthma outcome measures. OBJECTIVES: We aimed to assess the association of short-term air pollutant exposure with the use of short-acting beta-2 agonists (SABA) for asthma by monitoring the time and place of occurrence with electronic medication monitors. METHODS: In a cohort of adults and children with asthma (n = 287; 60% female), we deployed electronic medication monitors fitted to metered-dose inhalers to monitor SABA use, capturing the date, time and location of use. We assigned pollutant exposures based on each actuation's time and location (4-h mean measures for ozone and particulate matter of 2.5 µm or smaller (PM2.5)), assessed associations using generalized linear models and explored age-specific effects. MEASUREMENTS AND MAIN RESULTS: Ambient ozone exposure was positively associated with SABA use (p = 0.01). Age-specific associations were identified (interaction p = 0.01), with a larger increase in SABA use for children (11.3%; 95% CI: 7.0%-18.2%) than adults (8.4%; 95% CI: 6.4%-11.0%) per IQR increase of ozone (16.8 ppb). CONCLUSIONS: These findings support existing evidence that short-term exposure to ozone can cause morbidity in individuals with asthma, and suggest that ozone exposures below the current U.S. EPA standard may be associated with increased SABA use.

Anterior capsulotomy for obsessive-compulsive disorder: a review of old and new literature.

Over the last two decades, deep brain stimulation (DBS) has gained popularity as a treatment of severe and medically refractory obsessive-compulsive disorder (OCD), often using brain targets informed by historical lesional neurosurgical procedures. Paradoxically, the use of DBS in OCD has led some multidisciplinary teams to revisit the use of lesional procedures, especially anterior capsulotomy (AC), although significant aversion still exists toward the use of lesional neurosurgery for psychiatric disorders. This paper aims to review all literature on the use of AC for OCD to examine its effectiveness and safety profile.All publications on AC for OCD were searched. In total 512 patients were identified in 25 publications spanning 1961-2018. In papers where a Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score was available, 73% of patients had a clinical response (i.e., > 35% improvement in Y-BOCS score) and 24% patients went into remission (Y-BOCS score < 8). In the older publications, published when the Y-BOCS was not yet available, 90% of patients were deemed to have had a significant clinical response and 39% of patients were considered symptom free. The rate of serious complications was low.In summary, AC is a safe, well-tolerated, and efficacious therapy. Its underuse is likely a result of historical prejudice rather than lack of clinical effectiveness.