Biomechanical and ergonomic risks associated with cervical musculoskeletal dysfunction amongst surgeons: A systematic review.

INTRODUCTION: Surgeons are at high risk of developing musculoskeletal symptoms due to a range of factors including, maladaptive positioning and surgical ergonomics. Cervical muscle strain and biomechanical load is most prevalent due to repetitive motions and prolonged static neck positioning. This issue is apparent through reports of prevalence between 10 and 74.4% among surgeons. The aim of this systematic review is to provide an objective assessment of the clinical evidence available and a descriptive analysis of the effects of kinematics and surgical ergonomics on the prevalence of surgeons' cervical musculoskeletal pain. METHODS: This is PRISMA-compliant systematic review of clinical studies assessing the prevalence of cervical musculoskeletal dysfunction in surgeons by searching PUBMED and Ovid EMBASE databases from inception to 19th October 2023. Study quality was graded according to the National Institutes of Health study quality assessment tools. RESULTS: A total of 9 studies were included in the final qualitative analysis. The use of loupes, open surgery and excessive neck flexion (>30°) were associated with cervical dysfunction. Comparison of study outcomes was challenging due to heterogeneity within study methods and the paucity of methodological quality. CONCLUSION: The current literature assessing ergonomic and biomechanical factors predisposing surgeons to cervical musculoskeletal dysfunction is insufficient to provide reliable guidance for clinicians. Although the literature identifies factors contributing to work-related cervical dysfunction, few attempt to evaluate interventions for improved surgical ergonomics. An objective assessment of interventions that prompt postural correction with the aim to improve neck pain in surgeon cohorts is warranted.

Nail gun injury to the median nerve: A barbed issue.

Nail gun injuries to the hand are an increasingly common encounter amongst those in the construction injury and a frequent presentation to the emergency department. Despite their frequency, nail gun injuries rarely involve significant structural injury. We present a rare case of severe injury by a barbed nail to the median nerve requiring surgical exploration. At our latest follow up 14 months post-operatively, the patient had ongoing sensory and motor deficits, cold intolerance and reduced proprioception and range of motion at the index finger. Continued hand therapy resulted in improved range of motion and desensitization. A systematic literature search has revealed no other reported cases of median nerve injury by nail gun.

Brain charts for the human lifespan.

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

Muir-Torre syndrome: a case of unusual coexisting genetic mutations.

Patients with Muir-Torre syndrome (MTS) commonly have germline mismatch repair mutations in MLH1, MSH2 or MSH6, with a strong predominance in MSH2. A subset of approximately one-third of patients will instead have an autosomal recessive base excision repair mutation in MUTYH called MUTYH polyposis. To the best of our knowledge, this is the first report of coexisting germline MSH2 and MUTYH mutations in a patient with MTS.

Neural substrates of norm compliance in perceptual decisions.

Societal norms exert a powerful influence on our decisions. Behaviours motivated by norms, however, do not always concur with the responses mandated by decision relevant information potentially generating a conflict. To probe the interplay between normative and informational influences, we examined how prosocial norms impact on perceptual decisions subjects made in the context of a simultaneous presentation of social information. Participants displayed a bias in their perceptual decisions towards that mandated by social information. However, normative prescriptions modulated this bias bi-directionally depending on whether norms mandated a decision in accord or contrary to the contextual social information. At a neural level, the addition of a norms increased activity in prefrontal cortex and modulated functional connectivity between prefrontal and parietal areas. The bi-directional effect of our norms was captured by differential activations when participants decided against the social information. When norms indicated a decision in line with social information, non-compliance modulated lateral prefrontal cortex activity. By contrast, when norms mandated a decision against social information norm compliance increased activity in the anterior cingulate cortex. Hence, social norms changed the balance between a reliance on perceptual and social information by modulating brain activity in regions associated with response inhibition and conflict monitoring.

The impact of traumatic stress on Pavlovian biases.

BACKGROUND: Disturbances in Pavlovian valuation systems are reported to follow traumatic stress exposure. However, motivated decisions are also guided by instrumental mechanisms, but to date the effect of traumatic stress on these instrumental systems remain poorly investigated. Here, we examine whether a single episode of severe traumatic stress influences flexible instrumental decisions through an impact on a Pavlovian system. METHODS: Twenty-six survivors of the 2011 Norwegian terror attack and 30 matched control subjects performed an instrumental learning task in which Pavlovian and instrumental associations promoted congruent or conflicting responses. We used reinforcement learning models to infer how traumatic stress affected learning and decision-making. Based on the importance of dorsal anterior cingulate cortex (dACC) for cognitive control, we also investigated if individual concentrations of Glx (=glutamate + glutamine) in dACC predicted the Pavlovian bias of choice. RESULTS: Survivors of traumatic stress expressed a greater Pavlovian interference with instrumental action selection and had significantly lower levels of Glx in the dACC. Across subjects, the degree of Pavlovian interference was negatively associated with dACC Glx concentrations. CONCLUSIONS: Experiencing traumatic stress appears to render instrumental decisions less flexible by increasing the susceptibility to Pavlovian influences. An observed association between prefrontal glutamatergic levels and this Pavlovian bias provides novel insight into the neurochemical basis of decision-making, and suggests a mechanism by which traumatic stress can impair flexible instrumental behaviours.

The tooth, the whole tooth and nothing but the tooth: tooth shape and ontogenetic shift dynamics in the white shark Carcharodon carcharias.

Results from this study of the white shark Carcharodon carcharias include measurements obtained using a novel photographic method that reveal significant differences between the sexes in the relationship between tooth cuspidity and shark total length, and a novel ontogenetic change in male tooth shape. Males exhibit broader upper first teeth and increased distal inclination of upper third teeth with increasing length, while females do not present a consistent morphological change. Substantial individual variation, with implications for pace of life syndrome, was present in males and tooth polymorphism was suggested in females. Sexual differences and individual variation may play major roles in ontogenetic changes in tooth morphology in C. carcharias, with potential implications for their foraging biology. Such individual and sexual differences should be included in studies of ontogenetic shift dynamics in other species and systems.

Adolescent friendships predict later resilient functioning across psychosocial domains in a healthy community cohort.

BACKGROUND: Adolescence is a key time period for the emergence of psychosocial and mental health difficulties. To promote adolescent adaptive ('resilient') psychosocial functioning (PSF), appropriate conceptualisation and quantification of such functioning and its predictors is a crucial first step. Here, we quantify resilient functioning as the degree to which an individual functions better or worse than expected given their self-reported childhood family experiences, and relate this to adolescent family and friendship support. METHOD: We used Principal Component and regression analyses to investigate the relationship between childhood family experiences and PSF (psychiatric symptomatology, personality traits and mental wellbeing) in healthy adolescents (the Neuroscience in Psychiatry Network; N = 2389; ages 14-24). Residuals from the relation between childhood family experiences and PSF reflect resilient functioning; the degree to which an individual is functioning better, or worse, than expected given their childhood family experiences. Next, we relate family and friendship support with resilient functioning both cross-sectionally and 1 year later. RESULTS: Friendship and family support were positive predictors of immediate resilient PSF, with friendship support being the strongest predictor. However, whereas friendship support was a significant positive predictor of later resilient functioning, family support had a negative relationship with later resilient PSF. CONCLUSIONS: We show that friendship support, but not family support, is an important positive predictor of both immediate and later resilient PSF in adolescence and early adulthood. Interventions that promote the skills needed to acquire and sustain adolescent friendships may be crucial in increasing adolescent resilient PSF.

Does Demand for Breast Augmentation Reflect National Financial Trends?

Aesthetic plastic surgery is a consumer-driven industry, subject to influence by financial forces. A changing economic environment may thus impact on the demand for surgery. The aim of this study was to explore trends in demand for bilateral breast augmentation (BBA) in consecutively presenting patients over an 11-year period and to examine if a correlation exists between these trends and changes in Gross Domestic Product (GDP), a key economic indicator. This study revealed a correlation between annual number of breast augmentation procedures performed and GDP values (r 2 = 0.34, p value = 0.059). Additionally, predicted number of BBA procedures, based on predicted GDP growth in Ireland, strongly correlated with actual number of BBA performed (r 2 = 0.93, p value = 0.000001). Predicted GDP growth can potentially forecast future demand for BBA in our cohort allowing plastic surgeons to modify their practice accordingly. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Increased fronto-striatal reward prediction errors moderate decision making in obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) has been linked to functional abnormalities in fronto-striatal networks as well as impairments in decision making and learning. Little is known about the neurocognitive mechanisms causing these decision-making and learning deficits in OCD, and how they relate to dysfunction in fronto-striatal networks. METHOD: We investigated neural mechanisms of decision making in OCD patients, including early and late onset of disorder, in terms of reward prediction errors (RPEs) using functional magnetic resonance imaging. RPEs index a mismatch between expected and received outcomes, encoded by the dopaminergic system, and are known to drive learning and decision making in humans and animals. We used reinforcement learning models and RPE signals to infer the learning mechanisms and to compare behavioural parameters and neural RPE responses of the OCD patients with those of healthy matched controls. RESULTS: Patients with OCD showed significantly increased RPE responses in the anterior cingulate cortex (ACC) and the putamen compared with controls. OCD patients also had a significantly lower perseveration parameter than controls. CONCLUSIONS: Enhanced RPE signals in the ACC and putamen extend previous findings of fronto-striatal deficits in OCD. These abnormally strong RPEs suggest a hyper-responsive learning network in patients with OCD, which might explain their indecisiveness and intolerance of uncertainty.

Computational neuroimaging strategies for single patient predictions.

Neuroimaging increasingly exploits machine learning techniques in an attempt to achieve clinically relevant single-subject predictions. An alternative to machine learning, which tries to establish predictive links between features of the observed data and clinical variables, is the deployment of computational models for inferring on the (patho)physiological and cognitive mechanisms that generate behavioural and neuroimaging responses. This paper discusses the rationale behind a computational approach to neuroimaging-based single-subject inference, focusing on its potential for characterising disease mechanisms in individual subjects and mapping these characterisations to clinical predictions. Following an overview of two main approaches - Bayesian model selection and generative embedding - which can link computational models to individual predictions, we review how these methods accommodate heterogeneity in psychiatric and neurological spectrum disorders, help avoid erroneous interpretations of neuroimaging data, and establish a link between a mechanistic, model-based approach and the statistical perspectives afforded by machine learning.

Size of common bile duct stones on MRCP predicts likelihood of positive findings at ERCP.

OBJECTIVE: To ascertain if direct measurement of the size of common bile duct stones (CBD) on magnetic resonance cholangio-pancreatography (MRCP) can be used to predict the likelihood of a positive endoscopic retrograde cholangio-pancreatography (ERCP) result. Should we be carrying out ERCPs on all patients with CBD stones? METHODS: We retrospectively analysed the records of 1812 consecutive patients undergoing MRCP between November 2009 and November 2014 at the Victoria Infirmary. A measurable CBD stone was present in 383 patients, of whom 293 successfully underwent ERCP. RESULTS: 221 patients (75%) had stones demonstrated on ERCP. A receiver operating curve (ROC) was plotted correlating stone size with the likelihood of a positive ERCP result, and demonstrates that using a cut off of >4 mm as an indication for ERCP gives the mathematical best-fit correlation with a sensitivity of 83% (95% CI 78-88) and specificity of 66% (95% CI 53-77). CONCLUSIONS: In our current practice, all patients with CBD stones at MRCP are considered for ERCP regardless of stone size. Our results would support the hypothesis that as size decreases the likelihood of spontaneous stone passage increases. Although the threshold of mathematical best compromise is >4 mm to minimise both type 1 and type 2 errors, we would favour a lower threshold of 2 mm above which ERCP is performed (sensitivity 98.65, 95% CI 96.1-99.7, specificity 25.71%, CI 16.0-37.6). For patients with stones measuring 2 mm or less, early operative intervention with intraoperative cholangiography to confirm duct clearance could be a suitable alternative.

Diaphragmatic hernia following oesophagectomy for oesophageal cancer - Are we too radical?

BACKGROUND: Diaphragmatic herniation (DH) of abdominal contents into the thorax after oesophageal resection is a recognised and serious complication of surgery. While differences in pressure between the abdominal and thoracic cavities are important, the size of the hiatal defect is something that can be influenced surgically. As with all oncological surgery, safe resection margins are essential without adversely affecting necessary anatomical structure and function. However very little has been published looking at the extent of the hiatal resection. We aim to present a case series of patients who developed DH herniation post operatively in order to raise discussion about the ideal extent of surgical resection required. METHODS: We present a series of cases of two male and one female who had oesophagectomies for moderately and poorly differentiated adenocarcinomas of the lower oesophagus who developed post-operative DH. We then conducted a detailed literature review using Medline, Pubmed and Google Scholar to identify existing guidance to avoid this complication with particular emphasis on the extent of hiatal resection. DISCUSSION: Extended incision and partial resection of the diaphragm are associated with an increased risk of postoperative DH formation. However, these more extensive excisions can ensure clear surgical margins. Post-operative herniation can be an early or late complication of surgery and despite the clear importance of hiatal resection only one paper has been published on this subject which recommends a more limited resection than was carried out in our cases. CONCLUSION: This case series investigated the recommended extent of hiatal dissection in oesophageal surgery. Currently there is no clear guidance available on this subject and further studies are needed to ascertain the optimum resection margin that results in the best balance of oncological parameters vs. post operative morbidity.

Unmasking Latent Inhibitory Connections in Human Cortex to Reveal Dormant Cortical Memories.

Balance of cortical excitation and inhibition (EI) is thought to be disrupted in several neuropsychiatric conditions, yet it is not clear how it is maintained in the healthy human brain. When EI balance is disturbed during learning and memory in animal models, it can be restabilized via formation of inhibitory replicas of newly formed excitatory connections. Here we assess evidence for such selective inhibitory rebalancing in humans. Using fMRI repetition suppression we measure newly formed cortical associations in the human brain. We show that expression of these associations reduces over time despite persistence in behavior, consistent with inhibitory rebalancing. To test this, we modulated excitation/inhibition balance with transcranial direct current stimulation (tDCS). Using ultra-high-field (7T) MRI and spectroscopy, we show that reducing GABA allows cortical associations to be re-expressed. This suggests that in humans associative memories are stored in balanced excitatory-inhibitory ensembles that lie dormant unless latent inhibitory connections are unmasked.

A quality improvement project using a problem based post take ward round proforma based on the SOAP acronym to improve documentation in acute surgical receiving.

OBJECTIVES: Ward round documentation provides one of the most important means of communication between healthcare professionals. We aimed to establish if the use of a problem based standardised proforma can improve documentation in acute surgical receiving. METHODS: Gold standards were established using the RCSE record keeping guidelines. We audited documentation for seven days using the following headings: patient name/identification number, subjective findings, objective findings, clinical impression/diagnosis, plan, diet status, discharge decision, discharge planning, signature, and grade. After the initial audit cycle, a ward round proforma was introduced using the above headings and re-audited over a seven day period. RESULTS: The pre-intervention arm contained 50 patients and the post intervention arm contained 47. The following headings showed an improvement in documentation compliance to 100%: patient name/identification number vs 96%, subjective findings vs 84%, objective findings vs 48%, plan vs 98%, signature vs 96%, and grade vs 62%. Documentation of the clinical impression/diagnosis improved to 98% vs 30%, diet status rose to 83% vs 16%, discharge decision to 66% vs 16%, and discharge planning to 40% vs 20%. CONCLUSIONS: Standardised proformas improve the documentation of post-take ward round notes. This helps to clarify the onward management plan for all aspects of a patient's care and will help avoid adverse events and litigation. This should improve the quality and safety of Patient Care.