Occam's razor

BACKGROUND: Acute pancreatitis (AP) is a disease spectrum ranging from mild to severe disease. During the coronavirus disease 2019 (COVID-19) pandemic, numerous reports of AP have been published, with most authors concluding a causal relationship between COVID-19 and AP. Retrospective case reports or small case series are unable to accurately determine the cause-effect relationship between COVID-19 and AP. AIM: To establish whether COVID-19 is a cause of AP using the modified Naranjo scoring system...

The importance of hip-spine syndrome in a nonarthritic population, in which patients present with coexisting symptoms in both the hip and lumbar spine, is becoming more clear. Several studies have shown inferior outcomes in patients undergoing treatment for femoral acetabular impingement syndrome with coexisting spinal symptoms. The most important factor when treating HSS patients is understanding each patient's pathology. A history and physical examination with provocative tests for spinal and hip pathology often provide the answer...

Subacute combined degeneration (SCD) from vitamin B12 deficiency and spinal stenosis from degenerative changes may present similarly with weakness, sensory disturbances, and ataxia but require different treatments. This case report describes a 74-year-old male with suspected SCD who was discharged to an inpatient rehabilitation facility (IRF), did not improve with B12 supplementation, and later developed signs of myelopathy and diffuse joint pain. He ultimately was found to have severe cervical stenosis and pseudogout that were treated with a laminectomy and colchicine, respectively...

Epidermolysis bullosa (EB) is a rare heterogeneous group of diseases which typically presents with extensive blistering and mucocutaneous erosions. EB is mechanobullous in nature and thus commonly involves sites of trauma and friction. It is a painful and disfiguring disorder. The involvement of different internal organs and systems, such as respiratory, genitourinary, and gastrointestinal systems, has been reported in the literature depending on the type of EB. We report a case of junctional epidermolysis bullosa (JEB) with urogenital involvement in a female child in Pakistan...

No abstract text is available yet for this article.

A 14-year-old girl presented with subacute onset headache, fever, and vomiting and was managed initially with antibiotics for suspected bacterial meningitis. Her symptoms further evolved over the next few weeks with systemic signs and symptoms favoring chronic meningitis with raised intracranial pressure. After the etiologic workup was unrevealing, she was started on empirical antituberculous therapy. After a period of partial improvement, symptoms recurred with a new-onset focal seizure. Her imaging findings evolved from features suggestive of focal leptomeningitis to multifocal heterogeneous enhancing cortical and subcortical lesions with hemorrhagic foci, leading to brain biopsy that confirmed diagnosis...

Occam's razor is the principle that, all else being equal, simpler explanations should be preferred over more complex ones 1 . This principle is thought to play a role in human perception and decision-making 2 , but the nature of our presumed preference for simplicity is not understood. Here we use preregistered behavioral experiments informed by formal theories of statistical model selection 3 to show that, when faced with uncertain evidence, human subjects exhibit preferences for particular, theoretically grounded forms of simplicity of the alternative explanations...

INTRODUCTION: The Tactical Combat Casualty Care (TCCC) card has undergone several changes since its first introduction in 1996. In 2013, updates to the card included more data points to increase prehospital documentation quality and enable performance improvement. This study reviews the proportions of data collected before and after the implementation of the new TCCC card. METHODS: This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR) focused on prehospital medical care...

INTRODUCTION: The Tactical Combat Casualty Care (TCCC) card has undergone several changes since its first introduction in 1996. In 2013, updates to the card included more data points to increase prehospital documentation quality and enable performance improvement. This study reviews the proportions of data collected before and after the implementation of the new TCCC card. METHODS: This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR) focused on prehospital medical care...

No abstract text is available yet for this article.

No abstract text is available yet for this article.

Diagnostic heuristics help ease the cognitive load in our day-to-day work. Occam's razor or the rule of diagnostic parsimony is a diagnostic heuristic often applied in dermatology. Occam's razor dictates that all things being equal, one diagnosis (as opposed to several diagnoses) should be sought to explain a patient's presentation. While this can often be helpful, it can also obscure the full picture. Hickam's Dictum is an aphorism expressing the opposite opinion: "patients can have as many diseases as they damn (or darn) well please...

Dual molecular diagnoses are defined as the presence of pathogenic variants at two distinct and independently segregating loci that cause two different Mendelian conditions. In this study, we report the identification of double genetic disorders in a series of patients with complex clinical features. In the last 24 months, 342 syndromic patients have been recruited and clinically characterised. Whole Exome Sequencing analysis has been performed on the proband and on both parents and identified seven patients affected by a dual molecular diagnosis...

We discuss V.P. Belavkin's approach to the Schrödinger cat problem and show its close relation to ideas based on superselection and interaction with the environment developed by N.P. Landsman. The purpose of the paper is to explain these ideas in the most simple possible context, namely: discrete time and separable Hilbert spaces, in order to make them accessible to those coming from the philosophy of science and not too happy with idiosyncratic notation and terminology and sophisticated mathematical tools...

Estimating false discovery rates (FDRs) of protein identification continues to be an important topic in mass spectrometry-based proteomics, particularly when analyzing very large data sets. One performant method for this purpose is the Picked Protein FDR approach which is based on a target-decoy competition strategy on the protein level that ensures that FDRs scale to large data sets. Here, we present an extension to this method that can also deal with protein groups, i.e. proteins that share common peptides such as protein isoforms of the same gene...

BACKGROUND: Turner syndrome (TS) is a rare condition associated with a completely or partially missing X chromosome that affects 1 in 2500 girls. TS increases the risk of autoimmune diseases, including Graves' disease (GD). Moyamoya disease is a rare cerebral arteriopathy of unknown etiology characterized by progressive bilateral stenosis of the internal carotid artery and its branches. Both TS and GD have been associated with Moyamoya. Type 2 spinocerebellar ataxia (SCA2) is an autosomal dominant cerebellar ataxia caused by a CAG repeat expansion in ATXN2...

The human pelvis represents a wonderful example of apparent idealistic simplicity overwhelmed by realistic complexity. Traditionally, the pelvis has been termed a "ring" linking the lower extremity to the spine via the sacroiliac joint. In essence, the pelvis is the lowest vertebral level-"the hip bone's connected to the spine bone." Thus, the law of parsimony seemingly applies in the diagnosis and management of both arthritic and nonarthritic hip and spine disorders in isolation or combination. However, an inverse Occam's razor is much more likely...

INTRODUCTION: Nasal reconstruction has important functional and cosmetic considerations, as proper repair of nasal defects is necessary to maintain function of the nasal airway and to recreate the normal appearance of this central facial structure. Cheek advancement flaps provide matched, mobile and highly vascularized tissue for the reconstruction of nasal defects, allowing for the concealment of incisions within natural creases in a one-stage approach. However, cheek advancement flaps are often underutilized for nasal reconstruction because of their difficulty restoring nasal contour...

BACKGROUND: Diagnostic reasoning requires clinicians to think through complex uncertainties. We tested the possibility of a bias toward an available single diagnosis in uncertain cases. DESIGN: We developed 5 different surveys providing a succinct description of a hypothetical individual patient scenaric. Each scenario was formulated in 2 versions randomized to participants, with the versions differing only in whether an alternative diagnosis was present or absent...

We demonstrate the power of using symmetries for model selection in the context of mechanistic modelling. We analyse two different models called the power law model (PLM) and the immunological model (IM) describing the increase in cancer risk with age, due to mutation accumulation or immunosenescence, respectively. The IM fits several cancer types better than the PLM implying that it would be selected based on minimizing residuals. However, recently a symmetry-based method for model selection has been developed, which has been successfully used in an in silico setting to find the correct model when traditional model fitting has failed...