Neurological Examination: An Evaluation of Video-Based Learning.

Objective This study aimed to systematically review and assess educational YouTube videos on neurological examination. Methods YouTube was screened for educational videos on neurological examination. A scoring system (involving five major and six minor criteria) was used to assess videos. Educationally useful videos were defined as those satisfying all major criteria and at least three minor criteria; 2 points were allocated for each major criterion and 1 point for each minor criterion, thereby using a score of 13 as a threshold. Results A total of 500 videos were screened, and 128 videos were included in the final selection procedure. Only 55 videos were deemed as educationally useful; 13 of these videos focused on the general neurological examination, 10 on cranial nerves, 11 on the upper limb, five on the lower limb, three on reflexes, one on upper and lower limbs, one on gait, and 11 were in the form of lectures. Six (46.15%) of the educationally useful videos about general neurological exams, including the top three videos, were created by academic institutions, and three (23.07%) were book-related. Educationally useful videos were not the most viewed videos. None of the analyzed videos included the evaluation of the autonomic nervous system in the physical examination routine. Conclusions YouTube is an increasingly common source of educational videos for medical students. However, videos found on YouTube are not peer-reviewed and may be inaccurate, and the preponderance of videos available on the platform makes it difficult for students and educators to find good educational material. We provide a list of URLs of educationally useful videos for students and educators in neurology and offer suggestions for the creation of high-quality educational videos.

Evaluation of Cell-Specific Alterations in Alzheimer's Disease and Relevance of In Vitro Models.

Alzheimer's disease (AD) is a neurodegenerative disorder classically characterized by two neuropathological hallmarks: ß-amyloid plaques and tau tangles in the brain. However, the cellular and molecular mechanisms involved in AD are still elusive, which dampens the possibility of finding new and more effective therapeutic interventions. Current in vitro models are limited in modelling the complexity of AD pathogenesis. In this study, we aimed to characterize the AD expression signature upon a meta-analysis of multiple human datasets, including different cell populations from various brain regions, and compare cell-specific alterations in AD patients and in vitro models to highlight the appropriateness and the limitations of the currently available models in recapitulating AD pathology. The meta-analysis showed consistent enrichment of the Rho GTPases signaling pathway among different cell populations and in the models. The accuracy of in vitro models was higher for neurons and lowest for astrocytes. Our study underscores the particularly low fidelity in modelling down-regulated genes across all cell populations. The top enriched pathways arising from meta-analysis of human data differ from the enriched pathways arising from the overlap. We hope that our data will prove useful in indicating a starting point in the development of future, more complex, 3D in vitro models.

Sex and age dimorphism of the gut-brain axis in ischemic stroke: A systematic review of preliminary studies.

Recent studies have shown that stroke risk and outcomes are influenced by the microbiota composition and its strict relationship with the immune system. Age and sex are the main non-modifiable factors that shape microbiome composition. In order to evaluate the effects of these two variables on the microbiome in stroke pathogenesis we performed a systematic review of literature, including 10 studies in the final selection. In the critical analysis of data we focused on three aspects: gut permeability, molecular mediators (both inflammatory molecules and gut metabolites) and functional deficits. Males display higher post-stroke intestinal permeability than females and a youthful microbiome correlates with higher levels of mucin gene expression thus enhancing intestinal barrier function. Gut mast cells-derived histamine shows an age-dependent increase after stroke but it remains unknown whether it also shows sexual dimorphism in the context of stroke. IL-17 is significantly increased in males as compared to females. SCFAs promote recovery in aged mice. We registered a lack of evidence on the impact of hormonal differences on the stroke microbiome. An overall negative effect of aged microbiota on functional tests after stroke is a robust finding among many studies. However, the effects of sex-mediated microbiome variability on functional deficits after stroke remain elusive. The modifiable nature of the microbiome makes it suitable for therapeutic intervention, however we show that a lack of consideration for sex as a biological variable is a major limitation of current stroke clinical and pre-clinical microbiome research studies.

Gut permeability and osteoarthritis, towards a mechanistic understanding of the pathogenesis: a systematic review.

Osteoarthritis (OA) is the most common condition affecting human joints. Along with mechanical and genetic factors, low-grade inflammation is increasingly supported as a causal factor in the development of OA. Gut microbiota and intestinal permeability, via the disruption of tight junction competency, are proposed to explain a gut-joint axis through the interaction with the host immune system. Since previous studies and methods have underestimated the role of the gut-joint axis in OA and have only focussed on the characterisation of microbiota phenotypes, this systematic review aims to appraise the current evidence concerning the influence of gut permeability in the pathogenesis of OA. We propose that the tight junction disruption may be due to an increase in zonulin activity as already demonstrated for many other chronic inflammatory disorders. After years of unreliable quantification, one study optimised the methodology, showing a positive validated correlation between plasma lipopolysaccharide (LPS), obesity, joint inflammation, and OA severity. Chemokines show a prominent role in pain development. Our systematic review confirms preliminary evidence supporting a gut-joint axis in OA pathogenesis and progression. Being modifiable by several factors, the gut microbiota is a promising target for treatment. We propose a pathogenetic model in which dysbiosis is correlated to the bipartite graph of tight junctions and bacterially-produced products, aiming to direct future studies in the search of other bacterial products and tight junction disassembly regulators.KEY MESSAGESPrevious studies and methods have underestimated the impact of the gut-joint axis in osteoarthritis and have focussed on the characterisation of microbiota phenotypes rather than clear molecular mediators of disease.Gut dysbiosis is related to higher levels of bacterial toxins that elicit cartilage and synovium inflammatory pathways.Future research may benefit from focussing on both tight junctions and bacterially-produced products.