Association Between Patient and Physician Sex and Physician-Estimated Stroke and Bleeding Risks in Atrial Fibrillation

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.

Slipped Capital Femoral Epiphysis: Early Intervention and Referral

Slipped capital femoral epiphysis is the most common hip pathology in children aged 8–15 years old. Research has shown that when a nonorthopedic provider evaluates this patient population, there can be a significant delay in the appropriate treatment, which may have serious consequences for the prognosis of the patient. The delays are often caused by the practitioner's inability to put the clinical picture into focus with regard to how these patients typically present.. This article presents the demographics, clinical presentation, differential diagnosis, radiological and physical examination techniques, and prevention strategies to recognize this condition and provide early intervention.     

A Model for the Origin of Motion Direction Selectivity in Visual Cortex

Motion perception is a vital part of our sensory repertoire in that it contributes to navigation, awareness of moving objects, and communication. Motion sense in carnivores and primates originates with primary visual cortical neurons selective for motion direction. More than 60 years after the discovery of these neurons, there is still no consensus on the mechanism underlying direction selectivity. This paper describes a model of the cat''s visual system in which direction selectivity results from the well-documented orientation selectivity of inhibitory neurons: inhomogeneities in the orientation preference map for inhibitory neurons leads to spatially asymmetric inhibition, and thus to direction selectivity. Stimulation of the model with a drifting grating shows that direction selectivity results from the relative timing of excitatory and inhibitory inputs to a neuron. Using a stationary contrast-reversing grating reveals that the inhibitory input is spatially displaced in the preferred direction relative to the excitatory input, and that this asymmetry leads to the timing difference. More generally, the model yields physiologically realistic estimates of the direction selectivity index, and it reproduces the critical finding with contrast-reversing gratings that response phase advances with grating spatial phase. It is concluded that a model based on intracortical inhibition can account well for the known properties of direction selectivity in carnivores and primates.SIGNIFICANCE STATEMENT Motion perception is vital for navigation, communication, and the awareness of moving objects. Motion sense depends on cortical neurons that are selective for motion direction, and this paper describes a model for the physiological mechanism underlying cortical direction selectivity. The essence of the model is that intracortical inhibition of a direction-selective cell is spatially inhomogeneous and therefore depends on whether a stimulus generates inhibition before or after reaching the cell''s receptive field: the response is weaker in the former than in the latter case. If the model is correct, it will contribute to the understanding of motion processing in carnivores and primates.     

Higher serotonin transporter availability in early‐onset obsessive–compulsive disorder patients undergoing escitalopram treatment: A [11C]DASB PET study

Objective

Early‐onset obsessive–compulsive disorder (EOCD) and late‐onset obsessive–compulsive disorder (LOCD) are distinct subtypes of obsessive–compulsive disorder (OCD). OCD patients are treated with serotonin reuptake inhibitors, but the difference in serotonin transporter (SERT) availability between medicated EOCD and LOCD is unexplored yet.

Methods

Six EOCD and 6 LOCD patients were enrolled. They underwent serial [¹¹C]DASB positron emission tomography scans during maintenance therapy with escitalopram, and their plasma concentration of escitalopram was measured simultaneously with the scan. Then, the drug‐free binding potential of SERT was calculated by pharmacokinetic–pharmacodynamic modelling.

Results

In comparison with LOCD patients, SERT availability was significantly higher in the putamen of EOCD patients (U = 4, p = .026), but not in the caudate nucleus (U = 14, p = .589), thalamus (U = 16, p = .818), and dorsal raphe nucleus (U = 7, p = .093). Binding potential of putamen showed a negative correlation (r = ?.580, p = .048) with age of onset of the disease, but not with the Yale–Brown Obsessive Compulsive Scale scores.

Conclusions

These findings indicate that the earlier the age of onset of OCD, the less serotonergic pathology there is and that this difference remains even after long‐term serotonin reuptake inhibitor treatment. Clinically, it might suggest that nonserotonergic treatments would be a better option for EOCD patients.     

Resident hesitation in the operating room: does uncertainty equal incompetence?

Context

In postgraduate medical programmes, the progressive development of autonomy places residents in situations in which they must cope with uncertainty. We explored the phenomenon of hesitation, triggered by uncertainty, in the context of the operating room in order to understand the social behaviours surrounding supervision and progressive autonomy.

Methods

Nine surgical residents and their supervising surgeons at a Canadian medical school were selected. Each resident–supervisor pair was observed during a surgical procedure and subsequently participated in separate post‐observation, semi‐structured interviews. Constructivist grounded theory was used to guide the collection and analysis of data.

Results

Three hesitation‐related themes were identified: the principle of progress; the meaning of hesitation, and the judgement of competence. Supervisors and residents understood hesitation in the context of a core surgical principle we termed the ‘principle of progress’. This principle reflects the supervisors’ and residents’ shared norm that maintaining progress throughout a surgical procedure is of utmost importance. Resident hesitation was perceived as the first indication of a disruption to this principle and was therefore interpreted by supervisors and residents alike as a sign of incompetence. This interpretation influenced the teaching–learning process during these moments when residents were working at the edge of their abilities.

Conclusions

The principle of progress influences the meaning of hesitation which, in turn, shapes judgements of competence. This has important implications for teaching and learning in direct supervision settings such as surgery. Without efforts to change the perception that hesitation represents incompetence, these potential teaching–learning moments will not fully support progressive autonomy.