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 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.

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.

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.

Advanced risk prediction for aortic dissection patients using imaging-based computational flow analysis

Patients with either a repaired or medically managed aortic dissection have varying degrees of risk of developing late complications. High-risk patients would benefit from earlier intervention to improve their long-term survival. Currently serial imaging is used for risk stratification, which is not always reliable. On the other hand, understanding aortic haemodynamics within a dissection is essential to fully evaluate the disease and predict how it may progress. In recent decades, computational fluid dynamics (CFD) has been extensively applied to simulate complex haemodynamics within aortic diseases, and more recently, four-dimensional (4D)-flow magnetic resonance imaging (MRI) techniques have been developed for in vivo haemodynamic measurement. This paper presents a comprehensive review on the application of image-based CFD simulations and 4D-flow MRI analysis for risk prediction in aortic dissection. The key steps involved in patient-specific CFD analyses are demonstrated. Finally, we propose a workflow incorporating computational modelling for personalised assessment to aid in risk stratification and treatment decision-making.

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.

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.

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.

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.

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.

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.

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.

In-vivo blood flow parameters can predict at-risk aortic aneurysms and dissection: a comprehensive biomechanics model

Background

Abnormal blood flow patterns can alter the material properties of the thoracic aorta via altered vascular biology and tissue biomechanics. In-vivo haemodynamic assessment of the aorta is yet to penetrate clinical practice due to our limited understanding of its effect on aortic wall properties. The decision for surgical treatment is based on size thresholds, limited to a single measurement of aortic diameter from routine imaging, although many aortic dissections (40–60%) occur below these size thresholds. This multi-centre study aims to assess the clinical utility of biomechanics principles in thoracic aortic aneurysm (TAA) risk rupture prediction using a substantial sample size.

Methods

Fifty-five patients undergoing surgery for root or ascending TAA were recruited from five cardiac centres. Bicuspid aortic valves and connective tissue disease were excluded from this study.Haemodynamic assessment Pre-operative 4-dimensional flow magnetic resonance imaging (4D-MRI) were conducted. Direct 4D-flow analysis and computational fluid dynamics (CFD) were performed creating detailed wall shear stress (WSS) maps across the whole aneurysms. Aortic wall assessment The aneurysmal aortic sample was obtained from surgery and subjected to region specific uniaxial failure tests in the circumferential and longitudinal directions, as well as delamination testing within the aortic media. Whole aneurysm histological characterisation was also conducted using computational pathology techniques. Blood flow, tissue mechanics and microstructural properties were used to develop a risk prediction model with assessment of elastin, collagen and smooth muscle cell composition, as well as failure strain assessment and dissection energy function.

Results

Outcomes of mechanical properties were: Young's Elastic Modulus as a measure of aortic stiffness (0.85 MPa ±0.69), as well as maximal tensile strength (0.49 MPa ± 0.36), which demonstrated reduced aortic wall strength in the outer curvature. This correlated with increased wall shear stress (WSS) (up to 10 Pa) and flow velocity (up to 43 l/min). Regions of abnormal flow and tissue mechanics correlated significantly with degraded medial microstructure (elastin abundance: 34 vs 66%; collagen abundance 26 vs 57%, p&lt;0.05).

Conclusions

CFD modelling has the potential to provide a risk prediction of acute events in TAA beyond the current size classification, as validated by altered aortic tissue properties. Future longitudinal studies are warranted to validate this methods in moderately enlarging thoracic aortas.

Flow, mechanical, histology properties

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): NIHR Imperial College BRC

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.

A giant planet candidate transiting a white dwarf

Astronomers have discovered thousands of planets outside the Solar System¹, most of which orbit stars that will eventually evolve into red giants and then into white dwarfs. During the red giant phase, any close-orbiting planets will be engulfed by the star², but more distant planets can survive this phase and remain in orbit around the white dwarf^3,4. Some white dwarfs show evidence for rocky material floating in their atmospheres⁵, in warm debris disks^6-9 or orbiting very closely^10-12, which has been interpreted as the debris of rocky planets that were scattered inwards and tidally disrupted¹³. Recently, the discovery of a gaseous debris disk with a composition similar to that of ice giant planets¹⁴ demonstrated that massive planets might also find their way into tight orbits around white dwarfs, but it is unclear whether these planets can survive the journey. So far, no intact planets have been detected in close orbits around white dwarfs. Here we report the observation of a giant planet candidate transiting the white dwarf WD 1856+534 (TIC 267574918) every 1.4 days. We observed and modelled the periodic dimming of the white dwarf caused by the planet candidate passing in front of the star in its orbit. The planet candidate is roughly the same size as Jupiter and is no more than 14 times as massive (with 95 per cent confidence). Other cases of white dwarfs with close brown dwarf or stellar companions are explained as the consequence of common-envelope evolution, wherein the original orbit is enveloped during the red giant phase and shrinks owing to friction. In this case, however, the long orbital period (compared with other white dwarfs with close brown dwarf or stellar companions) and low mass of the planet candidate make common-envelope evolution less likely. Instead, our findings for the WD 1856+534 system indicate that giant planets can be scattered into tight orbits without being tidally disrupted, motivating the search for smaller transiting planets around white dwarfs.

Investigation of the safety and feasibility of AAV1/SERCA2a gene transfer in patients with chronic heart failure supported with a left ventricular assist device - the SERCA-LVAD TRIAL

The SERCA-LVAD trial was a phase 2a trial assessing the safety and feasibility of delivering an adeno-associated vector 1 carrying the cardiac isoform of the sarcoplasmic reticulum calcium ATPase (AAV1/SERCA2a) to adult chronic heart failure patients implanted with a left ventricular assist device. The SERCA-LVAD trial was one of a program of AAV1/SERCA2a cardiac gene therapy trials including CUPID1, CUPID 2 and AGENT trials. Enroled subjects were randomised to receive a single intracoronary infusion of 1 × 10¹³ DNase-resistant AAV1/SERCA2a particles or a placebo solution in a double-blinded design, stratified by presence of neutralising antibodies to AAV. Elective endomyocardial biopsy was performed at 6 months unless the subject had undergone cardiac transplantation, with myocardial samples assessed for the presence of exogenous viral DNA from the treatment vector. Safety assessments including ELISPOT were serially performed. Although designed as a 24 subject trial, recruitment was stopped after five subjects had been randomised and received infusion due to the neutral result from the CUPID 2 trial. Here we describe the results from the 5 patients at 3 years follow up, which confirmed that viral DNA was delivered to the failing human heart in 2 patients receiving gene therapy with vector detectable at follow up endomyocardial biopsy or cardiac transplantation. Absolute levels of detectable transgene DNA were low, and no functional benefit was observed. There were no safety concerns in this small cohort. This trial identified some of the challenges of performing gene therapy trials in this LVAD patient cohort which may help guide future trial design.

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.

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.

Twelve Tips for Students in Longitudinal Integrated Clerkships

This article was migrated. The article was marked as recommended. Longitudinal integrated clerkships (LICs) are a curricular structure for medical clerkships grounded in continuity across learning environments and experiences. There has yet to be a peer-reviewed article directly advising students in LIC programs. Twelve tips were created based on a comprehensive literature review of LICs and supported by the cumulative experience of the authors. They are ordered in four sequential groups: The first three tips discuss the importance of the relationships that are built between students and their patients (Tip 1), preceptors (Tip 2), and peers (Tip 3). Next we cover health systems, and offer advice on how students can integrate their learning (Tip 4), use technology to their advantage (Tip 5), and practice systems thinking (Tip 6). We then discuss the educational benefits when students take an active role in patient care (Tip 7), their own learning (Tip 8), and the feedback process (Tip 9). Finally, we cover the importance of self-care (Tip 10), reflection (Tip 11) and patience (Tip 12) during a LIC. These tips are designed to help students understand the pedagogical theory that underpins LICs, take an active role in their education, and maximize learning and wellness during their clerkship.

A survey of eight hot Jupiters in secondary eclipse using WIRCam at CFHT

We present near infrared high-precision photometry for eight transiting hot Jupiters observed during their predicted secondary eclipses. Our observations were carried out using the staring mode of the WIRCam instrument on the Canada-France-Hawaii Telescope (CFHT). We present the observing strategies and data reduction methods which delivered time series photometry with statistical photometric precision as low as 0.11%. We performed a Bayesian analysis to model the eclipse parameters and systematics simultaneously. The measured planet-to-star flux ratios allowed us to constrain the thermal emission from the day side of these hot Jupiters, as we derived the planet brightness temperatures. Our results combined with previously observed eclipses reveal an excess in the brightness temperatures relative to the blackbody prediction for the equilibrium temperatures of the planets for a wide range of heat redistribution factors. We find a trend that this excess appears to be larger for planets with lower equilibrium temperatures. This may imply some additional sources of radiation, such as reflected light from the host star and/or thermal emission from residual internal heat from the formation of the planet.

Complete heart block as the presenting feature in subarachnoid haemorrhage

Cardiac manifestations of subarachnoid haemorrhage (SAH) are well-documented phenomena that can complicate the treatment of this devastating condition. Here, we present a case of SAH presenting as complete heart block on initial assessment, an extremely rare event.A 53-year-old woman presented with a witnessed fall, sustaining a mild head injury. She denied any symptoms of SAH. Initial ECG revealed complete heart block, for which the patient was accepted under the cardiology team. For completion, a CT head scan was requested, this demonstrated significant SAH blood load in an aneurysmal rather than traumatic pattern. CT angiogram and subsequent digital subtraction angiography confirmed a posterior communicating artery aneurysm as the cause of the SAH. This case highlights the importance of considering neurological diagnoses in patients with collapse even with concomitant cardiac abnormalities, as the two are often inextricably linked.

The Constancy of Colored After-Images

We undertook psychophysical experiments to determine whether the color of the after-image produced by viewing a colored patch which is part of a complex multi-colored scene depends on the wavelength-energy composition of the light reflected from that patch. Our results show that it does not. The after-image, just like the color itself, depends on the ratio of light of different wavebands reflected from it and its surrounds. Hence, traditional accounts of after-images as being the result of retinal adaptation or the perceptual result of physiological opponency, are inadequate. We propose instead that the color of after-images is generated after colors themselves are generated in the visual brain.

Changing of the guard: reducing infection when replacing neural pacemakers

OBJECTIVE

Infection of deep brain stimulation (DBS) hardware has a significant impact on patient morbidity. Previous experience suggests that infection rates appear to be higher after implantable pulse generator (IPG) replacement surgery than after the de novo DBS procedure. In this study the authors examine the effect of a change in practice during DBS IPG replacements at their institution.

METHODS

Starting in January 2012, patient screening for methicillin-resistant Staphylococcus aureus (MRSA) and, and where necessary, eradication was performed prior to elective DBS IPG change. Moreover, topical vancomycin was placed in the IPG pocket during surgery. The authors then prospectively examined the infection rate in patients undergoing DBS IPG replacement at their center over a 3-year period with at least 9 months of follow-up.

RESULTS

The total incidence of infection in this prospective consecutive series of 101 IPG replacement procedures was 0%, with a mean follow-up duration of 24 ± 11 months. This was significantly lower than the authors' previously published historical control group, prior to implementing the change in practice, where the infection rate for IPG replacement was 8.5% (8/94 procedures; p = 0.003).

CONCLUSIONS

This study suggests that a change in clinical practice can significantly lower infection rates in patients undergoing DBS IPG replacement. These simple measures can minimize unnecessary surgery, loss of benefit from chronic stimulation, and costly hardware replacement, further improving the cost efficacy of DBS therapies.

The transiting dust clumps in the evolved disc of the Sun-like UXor RZ Psc

RZ Psc is a young Sun-like star, long associated with the UXor class of variable stars, which is partially or wholly dimmed by dust clumps several times each year. The system has a bright and variable infrared excess, which has been interpreted as evidence that the dimming events are the passage of asteroidal fragments in front of the host star. Here, we present a decade of optical photometry of RZ Psc and take a critical look at the asteroid belt interpretation. We show that the distribution of light curve gradients is non-uniform for deep events, which we interpret as possible evidence for an asteroidal fragment-like clump structure. However, the clumps are very likely seen above a high optical depth midplane, so the disc's bulk clumpiness is not revealed. While circumstantial evidence suggests an asteroid belt is more plausible than a gas-rich transition disc, the evolutionary status remains uncertain. We suggest that the rarity of Sun-like stars showing disc-related variability may arise because (i) any accretion streams are transparent and/or (ii) turbulence above the inner rim is normally shadowed by a flared outer disc.

Deep brain stimulation versus anterior capsulotomy for obsessive-compulsive disorder: a review of the literature

Obsessive-compulsive disorder (OCD) is a chronic and debilitating psychiatric condition. Traditionally, anterior capsulotomy (AC) was an established procedure for treatment of patients with refractory OCD. Over recent decades, deep brain stimulation (DBS) has gained popularity. In this paper the authors review the published literature and compare the outcome of AC and DBS targeting of the area of the ventral capsule/ventral striatum (VC/VS) and nucleus accumbens (NAcc).

Patients in published cases were grouped according to whether they received AC or DBS and according to their preoperative scores on the Yale-Brown Obsessive-Compulsive Scale (YBOCS), and then separated according to outcome measures: remission (YBOCS score < 8); response (≥ 35% improvement in YBOCS score); nonresponse (< 35% improvement in YBOCS score); and unfavorable (i.e., worsening of the baseline YBOCS score).

Twenty studies were identified reporting on 170 patients; 62 patients underwent DBS of the VC/VS or the NAcc (mean age 38 years, follow-up 19 months, baseline YBOCS score of 33), and 108 patients underwent AC (mean age 36 years, follow-up 61 months, baseline YBOCS score of 30). In patients treated with DBS there was a 40% decrease in YBOCS score, compared with a 51% decrease for those who underwent AC (p = 0.004). Patients who underwent AC were 9% more likely to go into remission than patients treated with DBS (p = 0.02). No difference in complication rates was noted.

Anterior capsulotomy is an efficient procedure for refractory OCD. Deep brain stimulation in the VC/VS and NAcc area is an emerging and promising therapy. The current popularity of DBS over ablative surgery for OCD is not due to nonefficacy of AC, but possibly because DBS is perceived as more acceptable by clinicians and patients.

Stenting as monotherapy for uncoilable intracranial aneurysms

BACKGROUND

Small, blister-like aneurysms (BLAs), by virtue of their unique morphology, are difficult to treat with conventional modalities. The use of oversized self-expanding stents as monotherapy for BLAs is a relatively new and promising concept that warrants further investigation.

OBJECTIVE

To clarify the role of oversized self-expanding stents as monotherapy for BLAs.

METHODS

Five consecutive patients were treated for BLAs with oversized self-expanding stents alone by the senior author (K.R.B.). We report on their clinical and radiographic outcomes.

RESULTS

All 5 patients in our series were discharged in good clinical condition. Complete aneurysm occlusion was observed in all patients at the time of most recent radiographic follow-up. Mean follow-up time was 13.6 months (range, 1 month to 4.5 years).

CONCLUSION

The use of oversized self-expanding stents to redirect flow away from aneurysms is an effective option for patients with BLAs. This approach represents an alternative to the use of flow diverters.

Tissue plasminogen activator via cross-collateralization for tandem internal carotid and middle cerebral artery occlusion

Tandem internal carotid and middle cerebral artery occlusion after carotid dissection predicts poor outcome after systemic thrombolysis. Current treatments include the use of endovascular carotid stenting, which carries with it a high risk of propagating further embolic events and worsening the dissection. New strategies for avoiding the aforementioned side-effects include recanalization using cross-collaterals for delivery of intra-lesional tissue plasminogen activator (tPA). We present two cases that provide further support for this novel approach. Both patients presented with a National Institute of Health Stroke Scale of 20, received intra-arterial tPA via cross-collateralization, and made full recoveries without the need for stenting.

Abstract 134: Endovascular Revascularization Is Associated With Better Outcomes Than Systemic Throbmolysis Alone For Tandem Internal Carotid And Middle Cerebral Artery Occlusion

Background and Purpose: Tandem Internal Carotid Artery and Middle Cerebral Artery or “TIM” occlusions are highly resistant to conventional therapy (systemic thrombolysis) and independently predicts poor patient outcome. Recent evidence suggests that patients treated more aggressively with either endovascular stenting of occluded carotid arteries and/or intra-arterial tissue plasminogen activator (tPA) may have superior outcomes. Here we evaluate all the available data to help assess the best intervention for this patient population that currently has limited treatment options.

Methods: Data from Medline and the Cochrane database of systemic reviews was searched. The search terms used includes (tandem OR combined) AND (middle cerebral OR internal carotid) AND (OCCLU* or lesion or stenos* or blocka*). All studies had to be in English. All duplicates were identified and removed. To be included the studies needed to report on three key aspects: 1) baseline characteristics (age; NIHSS at presentation); 2) treatment (time to treatment; modality); and 3) outcome (report of patient state at discharge or follow up on the Modified Rankin Scale). Patients were grouped according to whether they received endovascular intervention or stand alone IV tPA. Patients were considered independent if they had a Modified Rankin Scale score of ≤ 2 at follow up or discharge.

Results: Over 2,500 studies were evaluated. Seventeen studies met the inclusion criteria, with a total of 219 patients. Patients treated with endovascular therapy (n=60) (stenting and/or intra-arterial tPA) were 32% more likely to be independent (p<0.0001) and 28% less likely to have a significant disability (p= 0.0004) compared to patients given systemic thrombolysis (n=139). There was no significant difference in mortality or complication rates between the groups.

Conclusion: Endovascular therapy appears to be superior compared with systemic thrombolysis in treating patients with TIM occlusions. The risk of iatrogenic complications with more aggressive intervention does not appear to outweigh the outcome benefit. Further and larger studies are needed to assess the benefits and risks of endovascular therapy in patients with TIM lesions.

Mechanical properties of mitral allografts are not reasonably influenced by cryopreservation in sheep model

A mitral allograft is used exceptionally in the mitral, as well as in the tricuspid position, mostly as an experimental surgical procedure. The authors decided to evaluate the possibility of inserting a cryopreserved mitral allograft into the tricuspid position in a sheep experimental model. Within the framework of this experimental project the mechanical properties of the cryopreserved mitral allograft were tested. A novel methodology studying the functional unit composed of mitral annulus, leaflet, chordae tendinaea, and papillary muscle is presented. A five-parameter Maxwell model was applied to characterize the viscoelastic behavior of sheep mitral valves. A control group of 39 fresh mitral specimens and a test group of 13 cryopreserved mitral allografts from tissue bank were tested. The testing protocol consisted of six loading cycles with 1 mm elongation every 5 min. There was no significant difference in the mean values of the determined parameters (p>0.05) which confirms the main hypothesis that cryopreservation does not influence significantly material parameters characterizing the tissue mechanics. Slight discrepancy is observed in variances of viscous parameters suggesting that the values of the test group may be spread over larger interval due to the treatment.