Solution of the random field XY magnet on a fully connected graph

We use large deviation theory to obtain the free energy of the XY model on a fully connected graph on each site of which there is a randomly oriented field of magnitude $h$. The phase diagram is obtained for two symmetric distributions of the random orientations: (a) a uniform distribution and (b) a distribution with cubic symmetry. In both cases, the ordered state reflects the symmetry of the underlying disorder distribution. The phase boundary has a multicritical point which separates a locus of continuous transitions (for small values of $h$) from a locus of first order transitions (for large $h$). The free energy is a function of a single variable in case (a) and a function of two variables in case (b), leading to different characters of the multicritical points in the two cases.

How to manage bleeding disorders in aging patients needing surgery

With improvements in medical care, the life expectancy of patients with bleeding disorders is approaching that of the general population. A growing population of older adult patients with bleeding disorders is at risk of age-related comorbidities and in need of various elective and emergent age-related procedures. The increased risk of thrombosis and volume overload in older adults complicates perioperative hemostatic management. Furthermore, antithrombotic treatment such as antiplatelet or anticoagulant therapy, which is frequently required for various cardiovascular interventions, requires a meticulous individualized approach. Evidence-based guidelines for the management of aging patients with bleeding disorders are lacking, largely due to the underrepresentation of older adult patients in clinical trials as well as the rarity of many such bleeding disorders. We discuss the current guidelines and recommendations in the perioperative hemostatic management of older adult patients with hemophilia and von Willebrand disease as well as other rare bleeding disorders. The optimal management of these patients is often complex and requires a thorough multidisciplinary and individualized approach involving hematologists, surgeons, anesthesiologists, and the specialists treating the underlying disorder.

Emergence of Invasive Fungal Rhinosinusitis in Recently Recovered COVID-19 Patients

Objective: The risk of invasive fungal rhinosinusitis is increased in Coronavirus disease 2019 (COVID-19) because of its direct impact in altering innate immunity and is further exacerbated by widespread use of steroids/antibiotics/monoclonal antibodies. The study aims to describe this recently increased clinical entity in association with COVID-19. Method: A prospective, longitudinal study including patients diagnosed with acute invasive fungal rhinosinusitis (AIFRS) who recently recovered from COVID-19 infection or after an asymptomatic carrier state. A single-center, descriptive study investigating demographic details, clinical presentation, radio-pathological aspects, and advocated management. Result: A total of 21 patients were included with a mean age of 49.62 years (SD: 14.24). Diabetes mellitus (DM) was the most common underlying disorder (90.48%), and 63.16% of all patients with DM had a recent onset DM, either diagnosed during or after COVID-19 infection. Nineteen patients (90.48%) had recently recovered from active COVID-19 infection, and all had a history of prior steroid treatment (oral/parenteral). Remaining 2 patients were asymptomatic COVID-19 carriers. Surprisingly, 2 patients had no underlying disorder, and 5 (23.81%) recently received the Covishield vaccine. Fungal analysis exhibited Mucor (95.24%) and Aspergillus species (14.29%). Most common sign/symptom was headache and facial/periorbital pain (85.71%), followed by facial/periorbital swelling (61.90%). Disease involvement: sinonasal (100%), orbital (47.62%), pterygopalatine fossa (28.58%), infratemporal fossa (14.29%), intracranial (23.81%), and skin (9.52%). Exclusive endoscopic debridement and combined approach were utilized in 61.90% and 38.10%, respectively. Both liposomal amphotericin B and posaconazole were given in all patients except one. Conclusion: A high suspicion of AIFRS should be kept in patients with recent COVID-19 infection who received steroids and presenting with headache, facial pain, and/or facial swelling. Asymptomatic COVID-19 carriers and COVID-19 vaccinated candidates are also observed to develop AIFRS, although the exact immuno-pathogenesis is still unknown. Prompt diagnosis and early management are vital for a favorable outcome.

Ureterocele as a cause of chronic intractable abdominal pain

A ureterocele is a submucosal, cystic dilation of the terminal ureter, either congenital or acquired, as it enters the bladder. It is a rare clinical entity that can be entirely asymptomatic and present as an incidental finding or can manifest in the form of distressing symptoms such as unremitting abdominal pain, haematuria, obstructive uropathy, to name a few. The authors present a case of abdominal pain in a 43-year-old woman who was presumptively attributed to various clinical entities and was finally referred to the chronic pain clinic. The patient underwent numerous diagnostic tests, psychological evaluations and therapeutic interventions, including surgeries, over the years that failed to mitigate her symptoms until urologic imaging reported intravesical ureterocele as the underlying disorder. The case report entails the diagnostic challenge faced by the authors along with the clinical characteristics of ureterocele.

Are There Limits in Explainability of Prognostic Biomarkers? Scrutinizing Biological Utility of Established Signatures

Prognostic biomarkers can have an important role in the clinical practice because they allow stratification of patients in terms of predicting the outcome of a disorder. Obstacles for developing such markers include lack of robustness when using different data sets and limited concordance among similar signatures. In this paper, we highlight a new problem that relates to the biological meaning of already established prognostic gene expression signatures. Specifically, it is commonly assumed that prognostic markers provide sensible biological information and molecular explanations about the underlying disorder. However, recent studies on prognostic biomarkers investigating 80 established signatures of breast and prostate cancer demonstrated that this is not the case. We will show that this surprising result is related to the distinction between causal models and predictive models and the obfuscating usage of these models in the biomedical literature. Furthermore, we suggest a falsification procedure for studies aiming to establish a prognostic signature to safeguard against false expectations with respect to biological utility.

Etiology of Carpal Tunnel Syndrome in a Large Cohort of Children

(1) Background: Carpal tunnel syndrome (CTS), a compressive mononeuropathy of the median nerve at the wrist, is rare in childhood and occurs most frequently due to secondary causes. (2) Methods: Medical history, electrodiagnostic findings, and imaging data of patients with CTS from two pediatric neuromuscular centers were analyzed retrospectively. The etiology of CTS was investigated and compared with the literature. (3) Results: We report on a cohort of 38 CTS patients (n = 22 females, n = 29 bilateral, mean age at diagnosis 9.8 years). Electrodiagnostic studies of all patients revealed slowing of the antidromic sensory or orthodromic mixed nerve conduction velocities across the carpal tunnel or lack of the sensory nerve action potential and/or prolonged distal motor latencies. Median nerve ultrasound was diagnostic for CTS and confirmed tumorous and vascular malformations. Etiology was secondary in most patients (n = 29; 76%), and mucopolysaccharidosis was the most frequent underlying condition (n = 14; 37%). Idiopathic CTS was rare in this pediatric cohort (n = 9; 24%). (4) Conclusion: Since CTS in childhood is predominantly caused by an underlying disorder, a thorough evaluation and search for a causative condition is recommended in this age group.

Glucocorticoid induced adrenal insufficiency

ABSTRACTSynthetic glucocorticoids are widely used for their anti-inflammatory and immunosuppressive actions. A possible unwanted effect of glucocorticoid treatment is suppression of the hypothalamic-pituitary-adrenal axis, which can lead to adrenal insufficiency. Factors affecting the risk of glucocorticoid induced adrenal insufficiency (GI-AI) include the duration of glucocorticoid therapy, mode of administration, glucocorticoid dose and potency, concomitant drugs that interfere with glucocorticoid metabolism, and individual susceptibility. Patients with exogenous glucocorticoid use may develop features of Cushing’s syndrome and, subsequently, glucocorticoid withdrawal syndrome when the treatment is tapered down. Symptoms of glucocorticoid withdrawal can overlap with those of the underlying disorder, as well as of GI-AI. A careful approach to the glucocorticoid taper and appropriate patient counseling are needed to assure a successful taper. Glucocorticoid therapy should not be completely stopped until recovery of adrenal function is achieved. In this review, we discuss the factors affecting the risk of GI-AI, propose a regimen for the glucocorticoid taper, and make suggestions for assessment of adrenal function recovery. We also describe current gaps in the management of patients with GI-AI and make suggestions for an approach to the glucocorticoid withdrawal syndrome, chronic management of glucocorticoid therapy, and education on GI-AI for patients and providers.

Acute Movement Disorders in Childhood

Acute-onset movement disorders (MDs) are an increasingly recognized neurological emergency in both adults and children. The spectrum of possible causes is wide, and diagnostic work-up is challenging. In their acute presentation, MDs may represent the prominent symptom or an important diagnostic clue in a broader constellation of neurological and extraneurological signs. The diagnostic approach relies on the definition of the overall clinical syndrome and on the recognition of the prominent MD phenomenology. The recognition of the underlying disorder is crucial since many causes are treatable. In this review, we summarize common and uncommon causes of acute-onset movement disorders, focusing on clinical presentation and appropriate diagnostic investigations. Both acquired (immune-mediated, infectious, vascular, toxic, metabolic) and genetic disorders causing acute MDs are reviewed, in order to provide a useful clinician’s guide to this expanding field of pediatric neurology.

Symptomatic eating epilepsy: two novel pediatric patients and review of literature

Eating epilepsy (EE) is a form of reflex epilepsy in which seizures are triggered by eating. It is a rare condition but a high prevalence has been reported in Sri Lanka. In EE, the ictal semiology includes focal seizures with or without secondary generalization or generalized seizures. Some cases are idiopathic while focal structural changes on imaging, if present, are often confined to the temporal lobe or perisylvian region. On the other hand, some cases support the hypothesis of a genetic aetiology. The prognosis of EE is extremely variable due to the different nature of the underlying disorder. We describe two patients with symptomatic eating epilepsy, a 13-year-old boy with a bilateral perisylvian polymicrogyria and a 2-year-old boy with a genetic cause. The presence of structural lesions or the dysfunction of specific cortical regions in the context of a germline genetic alteration might lead to a hyperexcitation fostering the epileptogenesis. We review the available literature to clarify the aetiopathogenesis and the mechanisms underlying EE to improve the diagnosis and the management of these rare conditions.

Visualization of the epimysium and fascia thoracolumbalis at the lumbar spine using MRI

Background The fascia thoracolumbalis (FTL) is an important component for stabilization and motion control of the lumbar spine. It coordinates the traction forces of the autochthonous muscles of the back (AM) and connects them to the muscles of the abdominal wall, shoulder, and buttocks. Objectives The aim of our study was to describe the assessment of the normal FTL and epimysium of the AM in MRI and to identify patterns associated with pathological changes in the lumbar spine. Material and methods A total of 33 patients were retrospectively evaluated: 15 patients had no pathology at the lumbar spine; six patients had previous hemilaminectomy, three had spondylodesis, two had ventrolisthesis, and seven had scoliosis. The thickness of the FTL and EM was measured, and the adhesion of both structures was assessed. Results The fascial thickness at the levels of the lumbar vertebral bodies LVB 3 was 1.8, of LVB 4 it was 2.0, of LVB 5 it was 2.1, and at the sacral vertebra SVB 1 it was 1.8 mm. Fascial adhesions together with thickening of the EM occurred at the level of LVB 4 in 36% of the cases independently of the underlying disorder. Only thickening of the EM was seen in 48% of cases at the level of SVB 1. By contrast, adhesion of the FTL without epimysial changes occurred in 36% of cases at the level of LVB 3. Conclusion Thickening and adhesions at the EM and FTL occurred both postoperatively and in the case of scoliosis. Furthermore, lipomatous and muscular herniation could be detected in the FTL postoperatively. Epimysial and fascial alterations may be imaging manifestations of chronic myofascial back pain and should be included in radiological assessments.