bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetar as the Central Engine of AT2018cow: Optical, Soft X-Ray, and Hard X-Ray Emission
Authors: Li Long , Zhong Shu-Qing , Xiao Di , Dai Zi-Gao , Huang Shi-Feng , Sheng Zhen-Feng
Published: February 2024

AT2018cow is the most extensively observed and widely studied fast blue optical transient to date; its unique observational properties challenge all existing standard models. In this paper, we model the luminosity evolution of the optical, soft X-ray, and hard X-ray emission, as well as the X-ray spectrum of AT2018cow with a magnetar-centered engine model. We consider a two-zone model with a striped magnetar wind in the interior and an expanding ejecta outside. The soft and hard X-ray emission of AT2018cow can be explained by the leakage of high-energy photons produced by internal gradual magnetic dissipation in the striped magnetar wind, while the luminous thermal UV/optical emission results from the thermalization of the ejecta by the captured photons. The two-component energy spectrum yielded by our model with a quasi-thermal component from the optically thick region of the wind superimposed on an optically thin synchrotron component well reproduces the X-ray spectral shape of AT2018cow. The Markov Chain Monte Carlo fitting results suggest that in order to explain the very short rise time to peak of the thermal optical emission, a low ejecta mass M
ej ≈ 0.1 M
⊙ and high ejecta velocity

v

SN

≈
0.17
c

are required. A millisecond magnetar with P
0 ≈ 3.7 ms and B

p
≈ 2.4 × 1014 G is needed to serve as the central engine of AT2018cow.
JWST Observations of K2-18b Can Be Explained by a Gas-rich Mini-Neptune with No Habitable Surface
Authors: Wogan Nicholas F. , Batalha Natasha E. , Zahnle Kevin J. , Krissansen-Totton Joshua , Tsai Shang-Min , Hu Renyu
Published: February 2024

The James Webb Space Telescope (JWST) recently measured the transmission spectrum of K2-18b, a habitable-zone sub-Neptune exoplanet, detecting CH4 and CO2 in its atmosphere. The discovery paper argued the data are best explained by a habitable “Hycean” world, consisting of a relatively thin H2-dominated atmosphere overlying a liquid water ocean. Here, we use photochemical and climate models to simulate K2-18b as both a Hycean planet and a gas-rich mini-Neptune with no defined surface. We find that a lifeless Hycean world is hard to reconcile with the JWST observations because photochemistry only supports <1 part-per-million CH4 in such an atmosphere while the data suggest about ∼1% of the gas is present. Sustaining percent-level CH4 on a Hycean K2-18b may require the presence of a methane-producing biosphere, similar to microbial life on Earth ∼3 billion years ago. On the other hand, we predict that a gas-rich mini-Neptune with 100× solar metallicity should have 4% CH4 and nearly 0.1% CO2, which are compatible with the JWST data. The CH4 and CO2 are produced thermochemically in the deep atmosphere and mixed upward to the low pressures sensitive to transmission spectroscopy. The model predicts H2O, NH3, and CO abundances broadly consistent with the nondetections. Given the additional obstacles to maintaining a stable temperate climate on Hycean worlds due to H2 escape and potential supercriticality at depth, we favor the mini-Neptune interpretation because of its relative simplicity and because it does not need a biosphere or other unknown source of methane to explain the data.
Progenitors of Low-redshift Gamma-Ray Bursts
Authors: Petrosian Vahé , Dainotti Maria G.
Published: February 2024

The bimodal distribution of the observed duration of gamma-ray bursts (GRBs) has led to the identification of two distinct progenitors; compact star mergers, comprising either two neutron stars (NSs) or an NS and a black hole, for short GRBs (SGRBs), and the so-called collapsars for long GRBs (LGRBs). It is therefore expected that formation rate (FR) of LGRBs should be similar to the cosmic star formation rate (SFR), while that of SGRBs to be delayed relative to the SFR. The localization of some LGRBs in and around the star-forming regions of host galaxies and some SGRBs away from such regions support this expectation. Another distinct feature of SGRBs is their association with gravitational-wave (GW) sources and kilonovae. However, several independent investigations of the FRs of long and short bursts, using the Efron–Petrosian non-parametric method, have shown the presence of a mild luminosity evolution, and an LGRB FR that is significantly larger than SFR at low redshift, and similar to the FR of SGRBs. In addition, the recent discovery of association of two low-redshift LGRB 211211A and LGRB 230307A with a kilonova cast doubt about their collapsar origin. In this Letter we review these results and show that our results predict that about 60% ± 5% of LGRBs with redshift less than 2 could have compact star merger as progenitors increasing the expected rate of the GW sources and kilonovae significantly. The remaining 40% ± 5% have collapsars as progenitors, with some having associated supernovae.
Intermittent Electron-only Reconnection at Lunar Mini-magnetospheres
Authors: Stanier A. , Chen L. J. , Le A. , Halekas J. , Sawyer R.
Published: February 2024

Lunar crustal magnetic anomalies (LCMA) are sub-ion-gyroradius structures that have been shown to stand off the solar wind (SW) plasma from the Moon’s surface, forming shock-like discontinuities and reflecting incident SW protons. In this Letter, the results of high-resolution, 2D fully kinetic simulations show a bursty electron-only magnetic reconnection in the SW-LCMA interaction region, characterized by the quasiperiodic formation and ejection of magnetic islands and strong parallel electron flows along the X-point separator lines. The islands are observed to modify the magnetic pressure pileup and Hall electric field above the LCMA, leading to sharp increases in reflected protons that drive electromagnetic fluctuations downstream and short distances upstream in the SW.
The Buprestidae (Coleoptera, Buprestoidea) of the Tuscan Archipelago (Italy)
Authors: Forbicioni Leonardo , Tormen Nicola , Curletti Gianfranco , Bani Luciano , Di Giulio Andrea , Ruzzier Enrico
Published: February 2024

Buprestidae is a group of beetles of important conservation and phytosanitary value that is poorly studied in the Tuscan Archipelago and the limited faunistic knowledge available refers to a few scant historical records.

The present contribution increments the species documented in the Archipelago from 27 to 51, providing more than 300 georeferenced occurrence records, derived from both direct field research and citizen science via iNaturalist. Of particular importance is the discovery of Eurythyrea quercus on Isola d'Elba, an uncommon and localised species currently critically endangered.
Recommendation of Machine Learning Techniques for Software Effort Estimation using Multi-Criteria Decision Making
Authors: Kumar Ajay
Published: February 2024

 For the development of the software industry, Software Effort Estimation (SEE) is one of the essential tasks. Project managers can overcome budget and time overrun issues by accurately estimating a software project's development effort in the software life cycle. In prior studies, a variety of machine learning methods for SEE modeling were applied. The outcomes for various performance or accuracy measures are inconclusive. Therefore, a mechanism for assessing machine learning approaches for SEE modeling in the context of several contradictory accuracy measures is desperately needed. This study addresses selecting the most appropriate machine learning technique for SEE modeling as a Multi-Criteria Decision Making (MCDM) problem. The machine learning techniques are selected through a novel approach based on MCDM. In the proposed approach, three MCDM methods- Weighted Aggregated Sum Product Assessment (WASPAS), Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) were applied to determine the ranking of machine learning techniques on SEE performance based on multiple conflicting accuracy measures. For validating the proposed method, an experimental study was conducted over three SEE datasets using ten machine-learning techniques and six performance measures. Based on MCDM rankings, Random Forest, Support Vector Regression, and Kstar are recommended as the most appropriate machine learning techniques for SEE modeling. The results show how effectively the suggested MCDM-based approach can be used to recommend the appropriate machine learning technique for SEE modeling while considering various competing accuracy or performance measures altogether.
A new feather mite species of the genus Mycterialges Gaud & Atyeo, 1981 (Acari, Xolalgidae) from the Oriental Stork, Ciconia boyciana (Ciconiiformes, Ciconiidae) in Korea
Authors: Shim Jeong Hun , Han Yeong-Deok , Kim Sukyung , Ha Dongsoo , Shin Yongun , Eo Soo Hyung
Published: February 2024

A new feather mite species,Mycterialges boycianaesp. nov.(Xolalgidae), was identified from the Oriental Stork,Ciconia boycianaSwinhoe, 1873, in Korea. Males ofM. boycianaesp. nov.are distinguished fromMycterialges mesomorphusGaud & Atyeo, 1981, in having a single triangular prodorsal shield, sinuous margins of the opisthosoma located between setaee2 andh2 on the hysteronotal shield, an oval-shaped epiandrum without posterior extensions, a shorter tibia + tarsus IV than femoragenu IV, and an absent ambulacral disc of leg IV. Females differ in having a prodorsal shield with a posterior margin that is blunt-angular, and a concave posterior margin of the hysteronotal shield with posterior extensions. This study presents the first record of the feather mite genusMycterialgesin birds of the genusCiconia(Ciconiidae). Additionally, we determined the phylogenetic relationship among Ingrassiinae using the mitochondrial cytochromecoxidase subunit (COI).
Short-term urban resilience estimation after a hypothetical nuclear event
Authors: Profeta William H S , Neto Rocco Pascale , Silva Vitor W L , Bonfim Carlos Eduardo S , Curzio Rodrigo C , Stenders Ricardo M , Oliveira Ubiratan C , Oliveira Raquel A A Costa e , Federico Claudio A , Andrade Edson R
Published: February 2024

In the event of a hypothetical tactical nuclear device being detonated in a densely populated urban area, the first responders must be well-prepared to make immediate decisions with limited information. To aid in this preparation, a computer simulation using the HotSpot Health Physics code was conducted to model the detonation of a tactical nuclear device in an international airport and its surroundings, considering different yields ranging from 1 to 10 kilotons. The simulation was conservative and applied to a time window of 4 days in the initial phase of the response to the event. The simulation findings allow for assessing the immediate effects of the electromagnetic pulse (EMP) and the radioactive contamination plumes on an inhabited area. This assessment includes data on the size of impacted zones, compromise of critical local infrastructure, radiological risk to potentially affected populations, and estimation of urban resilience and its temporal dynamics. This information helps raise levels of protection and optimize available resources.
Novel categories of supra soft continuous maps via new soft operators
Authors: El-latif Alaa M. Abd , Alqahtani Mesfer H.
Published: February 2024

In this paper we continue presenting new types of soft operators for supra soft topological spaces (or SSTSs). Specifically, we investigate more interesting properties and relationships between the supra soft somewhere dense interior (or SS-sd-interior) operator, the SS-sd-closure operator, the SS-sd-cluster operator, and the SS-sd-boundary operator. We prove that the SS-sd-interior operator, SS-sd-boundary operator, and SS-sd-exterior operator form a partition for the absolute soft set. Furthermore, we apply the notion of SS-sd-sets to soft continuity. In addition, we use the SS-sd-interior operator and the SS-sd-closure operator to provide equivalent conditions and many characterizations for SS-sd-continuous, SS-sd-irresolute, SS-sd-open, SS-sd-closed, and SS-sd-homeomorphism maps. Examples include the following: The soft mapping is an SS-sd-homeomorphism if, and only if it is both SS-sd-continuous and an SS-sd-closed if, and only if, the soft mapping in addition to its inverse is SS-sd-continuous. Moreover, a bijective soft mapping is SS-sd-open if, and only if, it is SS-sd-closed. Furthermore, we provide many examples and counterexamples to show our results, which are extensions of previous studies. A diagram summarizing our results is also introduced.
Hardware-Free Network Internals Exploration
Authors: Liu Qian
Published: February 2024

In undergraduate computer networking courses, the ideal scenario involves demonstrating network communications with multiple interconnected computers and a packet sniffer tool. However, practical challenges arise when attempting hands-on exercises, such as accessing or reconfiguring physical computers for online networking practice. Additionally, certain network concepts, like routing and switching, are typically discussed theoretically due to the limitations of observing external network packet transfers and the constraints faced by institutions in maintaining the necessary hardware for hands-on practice. This paper introduces a simulation-based approach to facilitate the teaching and learning of computer networking internals in an online environment, eliminating the need for dedicated hardware devices. The paper outlines various simulation activities and experiments designed to assist instructors in teaching and enable students to explore these internal networking concepts effectively.
Disruptive Structural Design Technique for Fixed Jacket-Type Offshore Platforms
Authors: Chatterjee Prabir Kumar
Published: February 2024

The present work proposes a semi-empirical method to configure, size and carry out the preliminary design of a fixed offshore platform considering only a few basic input parameters when topside details are unavailable. Input parameters include the water depth, maximum wave height, design seismic coefficient, functional type of the offshore platform, a rough estimate of the gross topside weight (other than structure), the number of well conductors and the available information on piles axial capacity. The main objective of the work is to automatically create a design and produce material take-off (MTO) that is sufficient for tender documents. The computer program developed for the above purpose generates a detailed analytical model incorporating available knowledge on equipment layout and structural design. The program creates a design without actually carrying out any structural analysis and generates the MTO based on the model created by the program. The proposed designs are benchmarked against several existing designs. Notwithstanding the fact that a number of different structural designs can exist for the same input data, the estimated MTO's match closely with all existing designs. The most important advantage is the immediate availability of the structural analytical model for subsequent detailed analyses and initiates a 3D model for other engineering disciplines to build up equipment, piping, utilities, etc.
Analysis of two cross-contamination cases of Campylobacter jejuni foodborne disease in fragile subjects in the territory of a Local Health Authority in Tuscany, Italy
Authors: Marconi Francesca , Sartoni Martina , Girardi Clara , Rossi Aurelio , Carrini Matteo , Nuvoloni Roberta , Pedonese Francesca , Munaò Giovanni
Published: February 2024

Campylobacteriosis is the most reported foodborne disease in the European Union, with more than 100,000 confirmed cases annually. Human infection can be caused by a low infectious dose, and in fragile populations, the food disease can manifest itself in acute and severe forms. This study aims to analyze two cases of campylobacteriosis in fragile people caused by Campylobacter jejuni in 2023 in Tuscany and the actions of the Local Health Competent Authority. From the results of the related investigations, it was possible to attribute both cases of foodborne diseases to unsafe food management during preparation/administration. Given the peculiar characteristics of the etiological agent, it is necessary to focus the attention of the population, especially those who deal with fragile subjects, on the good hygiene practices to be followed both at home and in collective catering.
Impact of Covid-19 pandemic on the utilization and delivery of healthcare services among outpatients during the early phase of the pandemic in Nigeria
Authors: Aigbonoga Daniel E. , Obarombi Joshua T. , Shekinah Williams Y. , Adiat Tijani S. , Owoputi Taye D. , Jubril Adebimpe R. , Salawudeen Azeezat M. , Lawal Abiodun O. , Akintayo Abiodun D. , Oluwadamilare Faith A. , Oluwalana Similoluwa O. , Adesokan Dayo S. , Oguntoye Richard A.
Published: February 2024

Introduction. During the early phase of the COVID-19 pandemic, some infection control measures were implemented to keep people safe and control the spread of the virus. These measures however were observed to cause significant delay or interruption in the delivery and utilization of healthcare services. Objective. The purpose of this study was to determine the impact of the COVID-19 pandemic on the utilization and delivery of healthcare services by outpatients in Nigeria during the early phase of the pandemic Methods. We sampled 373 outpatients who had received healthcare services before and during the pandemic in the University College Hospital, Ibadan using convenience sampling. Descriptive and inferential statistics (t-test) were carried out and the level of significance was set as P0.05. Results. Healthcare utilization was significantly impacted by the pandemic as there was a reduction in hospital visits by patients during the pandemic (p 0.0003). Restriction of movement and fear of contracting the virus was identified as reasons for the reduction in healthcare services utilization in about 59% of the participants. Patients rated the quality healthcare services delivered to them as “average” during the pandemic as opposed to “good” before the pandemic. Conclusion. The findings of this study showed that the COVID-19 pandemic had a significant impact on patients’utilization of healthcare services as well as the delivery of adequate healthcare services in the hospital during the early phases of the pandemic. Therefore, we recommend that efforts be made to improve hospitals and nationwide preparednessfor future pandemics to prevent healthcare interference and delay.
Transfacetal Screw Fixation for Subaxial Cervical Spine
Authors: Singh Deepak K. , Singh Arun K. , Nayak Satish
Published: February 2024

Background and Introduction:

In the modern era of spine surgery for subaxial cervical spine, transfacetal screw fixation has evolved enormously. Transfacetal screw fixation for subaxial cervical spine is a biomechanically effective technique. In this fixation, four cortical surfaces of the facets are purchased by the transfacetal screws.

Objectives:

In this video, we demonstrated the surgical technique of posterior transfacetal screw fixation.

Surgical Technique:

Transfacetal screw fixation of subaxial cervical spine was done along with posterior decompression. The entry point of transfacetal screw was defined as 1 mm caudal to mid-point of lateral mass, and screws were directed perpendicular to facet joint in the sagittal plane and straight in the coronal plane. Bone chips were placed over decorticated lateral mass after decompression.

Result:

Patient had uneventful recovery and maintained good status at follow up.

Conclusion:

In subaxial cervical spine, transfacetal screw fixation is a biomechanically effective, rigid, and an inexpensive technique to obtain immediate rigid fixation.
Microneurosurgery for Spinal Dural Arteriovenous Fistula- Operative Video
Authors: Das Kuntal K , Nangarwal Bhawan , Gosal Jaskaran S , Bhaisora Kamlesh S , Srinivasan Rahul , Srivastava Arun K
Published: February 2024

Background and Introduction:

Spinal dural arteriovenous fistula (SDAVF) is a rare but curable condition. Microsurgery is a highly effective and readily affordable treatment modality.

Objective:

We present a surgical video of SDAVF to demonstrate the operative nuances involved.

Surgical Technique:

A 53-year-old wheelchair-bound man with spastic paraparesis for 1.5 years was found to have a SDAVF at L1/2 level with a single fistula point. During surgery, a L1-L2 laminectomy and durotomy revealed a dilated vein accompanying the nerve root exiting L1/2 foramen that showed early filling on indocyanine green (ICG) video angiography. This vein was occluded, and a segment of this vein was removed during surgery, which led to resumption of normal spinal cord perfusion.

Results:

The patient showed gradual recovery of lower limb motor power and improved to assisted ambulation after 3 months.

Conclusions:

Surgery is a simple, effective, and cost-effective treatment option in SDAVF.
Tumefactive Demyelinating Brain Lesion Developing after Administration of Adenovector-Based COVID-19 Vaccine
Authors: Garg Ravindra K , Malhotra Hardeep S , Kumar Neeraj , Pandey Shweta , Patil Manish R , Uniyal Ravi , Rizvi Imran
Published: February 2024

Background:

Postmarketing surveillance of COVID-19 vaccination reveals that the COVID-19 vaccine administration is associated with several rare but serious neurological complications.

Case Report:

We report a case of new-onset tumefactive demyelinating brain lesion that developed after administration of an adenovector-based COVID-19 vaccine. A middle-aged female presented with recent right hemiparesis, which was noticed 2 days after she received the first dose of the vaccine. Magnetic resonance imaging (MRI) revealed a large subcortical T2/FLAIR hyperintensities involving corpus callosum as well. The patient responded to oral methylprednisolone. At 4 weeks, a follow-up MRI revealed a reduction in size of the lesion.

Conclusion:

To conclude, adenovector-based COVID-19 vaccination may be associated with a tumefactive demyelinating lesion.
Clinical Characteristics and Course of Patients with Juvenile Dermatomyositis – Case Series
Authors: Rajarathinam Indhuja , Raghuram Jyothi , Rao Anand P
Published: February 2024

Background:

Juvenile dermatomyositis (JDM) is one of the commonest forms of inflammatory myositis in childhood.

Objective:

The objective study was to study the clinical characteristics and course of JDM patients.

Material and Methods:

Retrospective analysis of the charts of 25 JDM patients admitted to two hospitals in Bangalore from March 2011 to July 2017.

Results:

The mean age at onset of disease was 7.74 ± 3.74 years. The male to female ratio was 1.5:1. All patients had skin rashes typical of JDM and 24/25 had demonstrable muscle weakness. Six patients were either lost to follow-up or died. Of the remaining 19 patients, 11 (57.9%) had a monocyclic course, 5 (26.3%) patients had a chronic continuous course, and 3 (15.8%) patients had a polycyclic course.

Conclusions:

JDM though rare should always be considered in the differential diagnosis in any child with skin rash and muscle pains and weakness. When diagnosed early and treated appropriately, sustained remission without medications is possible in a good proportion of patients.
Carotid Artery Dissection and Aneurysm with Styloid Process Fracture
Authors: Sasaki Kento , Komatsu Fuminari , Kato Yoko , Hirose Yuichi
Published: February 2024

Background:

Mechanical stimulation may lead to internal carotid artery (ICA) dissection and aneurysm.

Case Description:

We encountered a rare case of ICA dissection and aneurysm with prolonged styloid process (SP) fracture. A 37-year-old sales worker presented with right-sided amaurosis fugax. After admission to a nearby optical clinic, he was admitted to our hospital. Computed tomography angiography (CTA) and digital subtraction angiography showed dissection and apparent aneurysmal change in the right cervical portion of the ICA. CTA also showed elongated SPs, so we diagnosed Eagle's syndrome, and fracture of the right-side process. After 2 weeks of antiplatelet therapy, the aneurysm enlarged and dissection remained, so we treated the patient with coil embolization and stenting.

Conclusion:

We encountered a rare case of ICA dissection and aneurysm with Eagle's syndrome. Endovascular treatment was performed because the SP was fractured.
Endoscopic Total Corpus Callosotomy and Pan Commissurotomy for Lennox–Gastaut Syndrome
Authors: Doddamani Ramesh , Kota Ravi Chandra , Ahemad Nihal , Chandra Sarat P. , Tripathi Manjari
Published: February 2024

Background:

Corpus callosotomy (CC) is a major disconnection procedure that functionally isolates the cerebral hemispheres, thereby interrupting the spread of epileptic activity from one hemisphere to the other. It is extremely useful in children suffering from non-localized drug refractory epilepsy, especially drop attacks. The technique has evolved from microscopic to minimally invasive endoscopic surgery. The extent of callosotomy also varies based on the institutional practices ranging from anterior 1/3rd to total corpus callosotomies (TCC). The performance of TCC in conjunction with anterior, posterior, and hippocampal commissurotomies was described for the first time by the senior author from our institution.

Objective:

To describe the technique of performing endoscopic total corpus callosotomy, and pan commissurotomy using the interhemispheric corridor.

Methods:

A seven-year-old right-handed male child with seizure onset at the age of six months presented with three types of semiologies consisting of myoclonic jerks, frequent head drops and tonic posturing involving right upper and lower limbs with secondary generalization.

Results:

Video electroencephalography (VEEG) revealed diffuse slowing of the background, and slow spike and wave pattern. Generalized paroxysmal fast activity (GPFA) was noted in the VEEG, suggestive of LGS. MRI brain revealed bilateral parieto-occipital gliosis and gross brain atrophy. Ictal SPECT localized to left temporo-occipital area, while magnetoencephalography revealed bilateral temporal localization. Patient underwent TCC with pancommissurotomy. The patient was seizure-free (ILAE Class 3) at one-year follow up with no drop attacks, and significant reduction noted in other seizure types.

Conclusion:

Endoscopic corpus callosotomy and pan commissurotomy using the interhemispheric corridor is an elegant and minimally invasive technique best suited for appropriately selected children with refractory epilepsy.
Pleomorphic Adenoma of the Orbital Ectopic Lacrimal Gland
Authors: Sharma Anil K , Sharma Raghavendra , Misra Somen , Misra Neeta , Ashik R , Hussain Nighat , Nayak Nitish , Singh Prashant R
Published: February 2024

Only three cases of pleomorphic adenomas (PAs) of ectopic lacrimal gland mass in deep orbital location have been reported in the literature. This report describes a case of PA of the ectopic lacrimal gland situated deep in the orbit leading to proptosis, which was managed successfully by supraorbital orbitotomy via eyebrow incision. A 60-year-old female presented with complaints of gradually progressive, painless proptosis of the right eye. Imaging revealed a well-defined circumscribed mass lesion in the right orbit located predominantly in the postero-superior aspect of the globe. The patient underwent complete excision through supraorbital orbitotomy approach, using eyebrow incision. There was no clinical evidence of recurrence at eight months follow up. In orbit, PAs of the ectopic lacrimal gland are extremely rare, and the success of the treatment depends on the removal of the tumor with its capsule.
Extra-Arachnoidal Dissection and Limited Meatal Drilling for Excision of Giant Vestibular Schwannomas
Authors: Gupta Sunil K , Gupta Darpan , Savardekar Amey
Published: February 2024

Background:

Surgical excision of giant (>4 cm size) vestibular schwannomas (VS) with preservation of facial nerve (FN) function remains a challenge.

Objective:

Our surgical technique using an extra-arachnoid plane of dissection and limited meatal drilling is described with the goal of improving FN preservation.

Methods:

Surgical results with respect to FN preservation were analyzed for two groups of giant VS patients: Group A–operated between 2002 and 2009 using “standard” surgical technique, group B—operated between 2009 and 2016 using extra-arachnoidal dissection and limited meatal drilling. All patients had a minimum follow-up of 1 year.

Results: Group A:

Of the 115 patients, total excision was possible in 103 (89.5%), near-total in 7 (6%), and subtotal in 5 (4.3%) patients. At a >6-month follow-up, 68 (59.1%) patients had good FN function (House-Brackmann [H&B] grades 1–2), while 21 (18.3%) patients had poor function (H&B grade 3–5). Grade 6 involvement was seen in 26 (22.6%). Five patients had lower cranial nerve impairment necessitating tracheostomy. Group B: Of the 98 patients, total excision was achieved in 70 (71.4%) patients, near-total in 9 (9.2%), and subtotal in 19 (19.4%). Four patients had repeat surgery; 14 underwent gamma-knife radiosurgery. At >6-month follow-up, 78 (79.5%) patients had good FN function (H&B grades 1–2), while 20 (20.4%) had poor function (H&B grade 3–5).

Conclusions:

With our 'modified' surgical technique of extra-arachnoidal dissection of VS throughout surgery and limited meatal drilling, an improved rate of functional FN preservation was observed.
Paediatric Pituitary Adenomas
Authors: Jayant Satyam Singh , Pal Rimesh , Rai Ashutosh , Gupta Kirti , Radotra Bishan Dass , Walia Rama , Dhandapani Sivashanmugam , Tripathi Manjul , Ahuja Chirag Kamal , Gupta Prakamya , Bhansali Anil , Das Liza , Dutta Pinaki
Published: February 2024

Context:

Paediatric pituitary adenomas (PPAs) are uncommon, with evidence confined to small cohorts.

Aim:

We aimed to elucidate the baseline profile and outcomes of PPAs in a large, contemporary, monocentric cohort.

Settings, Design:

Pituitary clinic at PGIMER over 8 years (2010-2018).

Subjects and Methods:

PPAs in patients (≤20 years at diagnosis) were included. A retrospective review of their baseline clinico-biochemical and radiological profiles and outcomes post pituitary surgery/medical management was performed.

Results:

There were a total of 74 patients, of which 42 were female. The median age was 15 (IQR 13-18) years. Corticotropinomas (32.4%) and somatotropinomas (25.7%) were common, with 1 case of TSHoma and pituitary blastoma. The most common presentation was headache (57%) overall and menstrual irregularities (64.2%) in girls. Most (78%) had macroadenomas. Prolactinomas showed an excellent response to primary medical therapy (83.3%). Transsphenoidal surgery was performed in 81% of patients. Diabetes insipidus (30%) and hyponatremia (26.7%) emerged as common postoperative complications. Adjuvant medical management was required in 25%, and radiotherapy in 18%. Remission rates in Cushing's and acromegaly were 62.5% and 57.8%, respectively, with long-term hormone deficits noted in one-third of patients.

Conclusion:

PPAs have unique features and management challenges, including effects on growth and puberty. Functional tumours and macroadenomas are common. Remission can be achieved in more than half of the patients, with endocrine deficits persisting in about a third of cases, needing long-term surveillance.
Neurosyphilis and High-Resolution Vessel Wall Imaging
Authors: Narvaez Eduardo de Oliveira , Ramos Marcelo de Carvalho , Faria do Amaral Lázaro Luís , Reis Fabiano
Published: February 2024

Syphilis is a reemergent infection worldwide. There has been a steady increase in incidence across many population groups in the last decades, requiring public health authorities' attention. We report a case of a 67-year-old man with neurosyphilis who presented with abrupt clinical ophthalmic changes and sensorineural hearing loss. The neuroradiological investigation demonstrated cranial nerves and vascular involvement, detected on high-resolution vessel wall imaging in brain magnetic resonance imaging. CSF and blood VDRL test were positive, as well as blood serum fluorescent treponemal antibody absorption test (FTA-ABS) and chemiluminescent magnetic microparticle immunoassay (CMIA). A test for the human immunodeficiency virus was negative. The patient was administered intravenous penicillin G for 21 days and was discharged well, with no neurologic signs.
Post-traumatic Oculomotor Nerve Palsy due to Intraneural Hemorrhage
Authors: Hegde Poonam P , Acharya Ullas V , Mahadevappa Manjunath
Published: February 2024

Oculomotor nerve palsy following traumatic brain injury is a rare entity. A head injury can result in diffuse neuronal axonal injury with subsequent microbleed within the nerve tissue. We report an unusual case of a patient who presented with complete isolated right third nerve palsy following a road traffic accident. In this patient, magnetic resonance imaging (MRI) revealed swelling and edema of the right oculomotor nerve along its cisternal segment with contrast enhancement. The acquisition of susceptibility-weighted images on MRI helped to clinch the diagnosis of intraneural hemorrhage as a cause of post-traumatic oculomotor nerve palsy.
Hereditary Sensory and Autonomic Neuropathy
Authors: Suthar Renu , Sharawat Indar K. , Eggermann Katja , Padmanabha Hansashree , Saini Arushi G. , Bharti Bhavneet , Kurth Ingo , Singhi Pratibha , Sankhyan Naveen
Published: February 2024

Objectives:

Hereditary sensory and autonomic neuropathy (HSAN) is a group of rare disorders affecting the sensory and autonomic neurons. Herein, we describe the clinical and genetic profile of six children with HSAN.

Methods:

Hospital records of six children diagnosed with HSAN over 7 years (2011–2018) were retrieved. Clinical features, electrophysiological studies, and genetic reports were collected from the case files.

Results:

The presenting clinical features in these six cases were developmental delay, recurrent febrile episodes, rhinitis, recurrent nonhealing ulcers, burns, self-mutilations, chronic osteomyelitis, and corneal ulcers. Electrophysiology studies showed predominant sensory axonal neuropathy. Autonomic features noted were recurrent fever, constipation, abdominal distension, hypertension, and vasomotor rhinitis. Genetic testing was done with next-generation sequencing in all six children. Causative genetic variants were identified in the NTRK1, PRDM12, DST gene, and a novel compound heterozygous variant in the FLVCR1 gene. The diagnosis of HSAN was delayed in most of our children due to variable presentation and lack of awareness among the treating paediatricians.

Conclusions:

Although the clinical presentation of HASN is highly variable, it is dominated by pain and temperature insensitivity and self-mutilation. Our report of six children with HSAN expands the existing knowledge on phenotype and genotype spectrum of HSAN.
A Rare Case of Eosinophilic Myelitis Due to Gnathostomiasis
Authors: Baskar Dipti , Nashi Saraswati , Reddy Ashok , Vangayalapati Sriharish , Arshad Faheem , Srijithesh PR , Kulkarni Girish , Alladi Suvarna , Wallop Pakdee , Ketboonlue Thawatchai , Dekumyoy Paron
Published: February 2024

Eosinophilic myelitis is an important cause of transverse myelopathy and has to be considered in an appropriate clinical setting. Eosinophilic myelitis due to parasitic infection should be suspected in cases with cerebrospinal fluid (CSF) eosinophilia along with migratory serpiginous skin lesions and recent travel to endemic areas. We report a case with a 1-month history of fever followed by truncal paresthesias, erythematous creeping skin eruptions, and paraparesis with blood and CSF eosinophilia on a background history of consuming undercooked fish. Magnetic resonance imaging (MRI) spine showed long segment T2 hyperintensities with contrast enhancement. He was tested positive for 24kDa antigenic component of Gnathostoma spinigerum in CSF and serum by immunoblot testing. The patient showed significant improvement with parenteral steroids.
Malignant Melanoma of the Brainstem
Authors: Meena Rajesh , Doddamani Ramesh S. , Gour Surya Sri K. , Mahajan Swati , Agrawal Deepak , Chandra P. Sarat
Published: February 2024

Background:

Primary intracranial malignant melanomas (PIMMs) are uncommon lesions of the central nervous system. Brainstem involvement is of rare occurrence.

Methods and Material:

A 33-year-old male presented with the chief complaints of progressively increasing headache, visual disturbances, and diplopia from the last 6 months. Magnetic resonance imaging (MRI) showed a well-defined lesion in the midbrain appearing heterogeneously hyperintense on T1WI and containing mixed hyperintense and hypointense areas on T2WI. Multiple areas of SWI blooming, suggestive of hemorrhage, were seen within the lesion.

Conclusion:

Brainstem malignant melanoma can masquerade cavernoma as seen in our case. Therefore, malignant melanomas should be considered in the differential diagnosis of brainstem lesions that presents with bleed.
Short-term Effect of Noninvasive Brain Stimulation Techniques on Motor Impairment in Chronic Ischemic Stroke
Authors: Narayan Sunil K , Jayan Jeshma , Arumugam Murugesan
Published: February 2024

Background:

In recent years, noninvasive brain stimulation (NIBS) has shown promise for stroke rehabilitation as a novel nonpharmaceutical neuromodulatory intervention with attractive neurophysiological theories backing it up.

Objective:

To find out the short-term effects of NIBS techniques on motor impairment in chronic ischemic stroke.

Materials and Methods:

A systematic review with meta-analysis was performed separately for transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), and studies that combined both, utilizing various databases for a period spanning from 2001 to 2019. Good-quality randomized controlled trials (RCTs) on chronic ischemic stroke cases with homogeneous clinical upper motor short-term outcome measures were considered for the meta-analysis. RevMan 5.1 software was used for the meta-analysis. Meta-analysis registration: CRD42021196299; https://www.crd.york.ac.uk/PROSPERO

Results:

A total of 319 studies were identified initially. After necessary filters to comply with the strict recruitment criteria, only four studies qualified, two each for tDCS and TMS and none qualified for analysis under the combined category. tDCS showed a nonsignificant effect on the upper limb motor function improvement (−0.10 [95% confidence interval {CI}: −0.84 to 0.64; I
2 0%; P = 0.8]), whereas the repetitive TMS showed a significant effect (0.75 [95% CI: 0.03–1.48; I
2 0%; P = 0.04]). The safety analysis did not reveal any major concerns for several published protocols.

Conclusions:

tDCS alone did not significantly benefit motor recovery; rTMS was effective in providing immediate functional benefits in chronic ischemic stroke. While the current stroke rehabilitation protocols with NIBS appear safe, more good-quality stratified RCTs with more innovative experimental protocols are needed to analyze and quantify the efficacy of these techniques in stroke rehabilitation.
Utility of DTI (Diffusion Tensor Imaging) Metrics to Study Microstructural Changes of Trigeminal Nerve in Patients with Trigeminal Neuralgia (TN)
Authors: Kumaran Sunitha Palasamudram , Gurram Sai Palasamudram , Viswamitra Sanjaya , Hegde Vinay
Published: February 2024

Aims:

To study the trigeminal nerve tractography and assessment of diffusion tensor imaging (DTI) parameters by comparing the values of fractional anisotropy (FA) of trigeminal (V) nerve on the affected side with that of the unaffected opposite side.

Materials and Methods:

Prospective comparative study done for one year included 30 patients who presented with trigeminal neuralgia and 30 controls who did not have any present or past history of neurological or neurosurgical symptoms were enrolled in the study.

Results:

Most common age of presentation of TN is >50 years, and the commonly involved branch is V2 (maxillary branch of the trigeminal nerve). Most of the patients were having symptoms for more than 1 year. The superior cerebellar artery was the most common vessel compressing the V nerve at the root entry zone (REZ), followed in the order by anterior inferior cerebellar artery and petrosal vein. Neurovascular compression (NVC) was more commonly seen in the study group when compared with the control group. In all the patients in the study group, fractional anisotropy (FA) was decreased on the affected side as compared to the unaffected side. In the study group, 10 patients were having NVC on both sides, but FA was significantly decreased only on the affected side. No significant difference in FA values at the REZ of bilateral V nerves in the control group.

Conclusion:

DTI metrics of the trigeminal nerve is a very helpful imaging technique in patients with trigeminal neuralgia. It not only helps in anatomical imaging but also reinforces the association between NVC and TN.
Meningo-Encephalitis due to Spotted Fever Group Rickettsia––A Rare Case Report with Serial Follow up MRI
Authors: Jena Subhransu S , Kar Mitalee , Soreng Indumati , Acharrya Sudeep , Misra Sudhi R
Published: February 2024

Spotted fever group (SFG) Rickettsial infection has rarely been reported to develop severe central nervous system involvement. We report a case of meningoencephalitis presenting with fever, headache, drowsiness, seizures, and a skin rash, showing ELISA IgM positivity to SFG Rickettsia group. MRI brain showed multifocal bilateral asymmetric patchy areas of T2W/FLAIR hyperintensity with significant diffusion restriction. Treatment with doxycycline resulted in clinical & radiological improvement. Rickettsial meningoencephalitis is a relatively under-diagnosed entity, probably due to the low index of suspicion and the lack of definitive diagnostic facilities in developing countries. This case was presented to highlight the importance of clinical suspicion mainly in endemic areas, the potential severity of the disease, and the need of early initiation of therapy to prevent mortality and long term neurological morbidity.
Hydatid Cyst of the Cerebellopontine Angle
Authors: Dere Ümit A , Şahintürk Fikret , Oktay Kadir , Altınörs Nur
Published: February 2024

Hydatid disease is caused by Echinococcus granulosus. The liver is the first organ of entry, while the central nervous system is affected in about 2% of cases. Primary brain hydatid cyst is extremely rare. The cysts are generally located in cerebral lobes. Here, we reported a 68-year-old Syrian immigrant woman with hydatid cyst in the left cerebellopontine angle. The patient presented gait disturbance, asymmetrical palatal arcs, negative gag reflex, and disturbed cerebellar tests on the left side. The patient was operated via suboccipital craniotomy. The cyst ruptured during manipulation, but it was totally removed.
MECP2 Mutations in the Rett Syndrome Patients from South India
Authors: Anitha Ayyappan , Poovathinal Suresh A , Viswambharan Vijitha , Thanseem Ismail , Iype Mary , Anoop U , Sumitha P S , Parakkal Rahna , Vasu Mahesh M
Published: February 2024

Background:

Rett syndrome (RTT) is a rare neurological disorder that primarily affects the females. Most cases of RTT are caused by a de novo mutation in the MECP2 gene located on the X chromosome. About 1000 MECP2 mutations have been found to be associated with RTT.

Objective:

The present study is aimed at the mutation screening of MECP2 gene in the RTT patients belonging to the south Indian state of Kerala.

Materials and Methods:

In total 22 girls with a clinical suspicion of RTT were recruited for the study. Exons 2, 3, and 4 of MECP2 were amplified and sequenced.

Results:

MECP2 mutations were observed in 12 patients. While 7 mutations were pathogenic, 4 were benign. All of the mutations were located in exons 3 and 4 of MECP2, spanning the methyl-CpG DNA binding domain (MBD), transcription repression domain (TRD), and C-terminal domain (CTD) domains of the MECP2 protein. Four novel mutations were identified. There were no mutations in the MECP2 gene of 10 patients with a clinical suspicion of RTT.

Conclusions:

A recommended screening strategy for RTT is to first look for mutations in exons 3 and 4 of MECP2, followed by exons 1 and 2, testing for large deletions in MECP2, and screening for mutations in genes, such as CDKL5 and FOXG1 that are reported to cause a Rett-like phenotype.
Radiation-Induced Intravascular Papillary Endothelial Hyperplasia in a Cavernous Sinus Hemangioma
Authors: Goyal-Honavar Abhijit , Balakrishnan Rajesh , Chacko Geeta , Chacko Ari G
Published: February 2024

Background:

Cavernous sinus hemangiomas are benign vascular tumors of the cavernous sinus. Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's angioma is a rare, aberrant thrombus organization occurring independently or in pre-existent lesions, and information on its occurrence in the intracranial region, or its management is sparse.

Objective:

We aim to describe a case of IPEH occurring in a pre-existing cavernous sinus hemangioma, treated with surgical excision and radiation therapy, providing insight into the appropriate treatment of these tumors and their response to therapy.

Materials and Methods:

We describe a right cavernous sinus hemangioma, recurring after initial radiation therapy and requiring surgical excision, at which point the presence of IPEH was noted. A sellar recurrence following partial excision was treated with hypofractionated Stereotactic radiotherapy (SRT), and this provided an excellent long-term outcome.

Conclusions:

Cavernous sinus hemangiomas are treated with surgical excision or primary radiation therapy. IPEH must be looked for in all excised specimens, as there are no radiological features that indicate its presence, and it may resemble the original lesion histologically. When detected, adjuvant radiation must be administered as the IPEH responds well to the use of radiation therapy.
Neurological Involvement in Malignant Atrophic Papulosis
Authors: Yousefi Samaneh , Borhani-Haghighi Afshin , Safari Anahid , Shapiro Lee
Published: February 2024

Malignant atrophic papulosis (MAP), or systemic Degos disease, is an obliterative vasculopathy of unknown origin, characterized by erythematous papules found on the skin, central nervous system (Neuro-MAP) and gastrointestinal tract. Neurological involvement occurs in approximately 20% of systemic cases, is progressive and largely fatal. It can be described in two forms: 1) the parenchymal presenting with meningoencephalitis and meningomyelitis and 2) the neurovascular presenting with large cerebral infarcts, intracranial and subarachnoid hemorrhage, subdural hematoma and venous sinus thrombosis. Predilection to subdural hematoma or hygroma is characteristic for neurological involvement in MAP in comparison to other vasculpathies and vasculitides. Peripheral nervous system manifestations are less common and include polyradiculopathy, neuropathy, and myopathy. CSF analysis usually shows mild to moderate pleocytosis, increased protein content, and normal glucose. Brain MRI may reveal cortical, subcortical and deep white matter ischemic lesions with possible nodular, leptomeningeal, dural, or ependymal enhancement. Spinal cord MRI may reveal patchy lesions from the periphery to the center or cord atrophy in progressive course. Neurological involvement in MAP has a grave prognosis. The interval from onset of papulosis to death averages two years in patients with neurological involvement. There is no confirmed treatment for MAP but there are promising reports with eculizumab and treprostinil.