Amar Dhand

The neurology of itch

Research over the past 15 years has helped to clarify the anatomy and physiology of itch, the clinical features of neuropathic itch syndromes and the scientific underpinning of effective treatments. Two itch-sensitive pathways exist: a histamine-stimulated pathway that uses mechanically insensitive C-fibres, and a cowhage-stimulated pathway primarily involving polymodal C-fibres. Interactions with pain continue to be central to explaining various aspects of itch. Certain spinal interneurons (Bhlhb5) inhibit itch pathways within the dorsal horn; they may represent mediators between noxious and pruritic pathways, and allow scratch to inhibit itch. In the brain, functional imaging studies reveal diffuse activation maps for itch that overlap, but not identically, with pain maps. Neuropathic itch syndromes are chronic itch states due to dysfunction of peripheral or central nervous system structures. The most recognized are postherpetic itch, brachioradial pruritus, trigeminal trophic syndrome, and ischaemic stroke-related itch. These disorders affect a patients quality of life to a similar extent as neuropathic pain. Treatment of neuropathic itch focuses on behavioural interventions (e.g., skin protection) followed by stepwise trials of topical agents (e.g., capsaicin), antiepileptic drugs (e.g., gabapentin), injection of other agents (e.g., botulinum A toxin), and neurostimulation techniques (e.g., cutaneous field stimulation). The involved mechanisms of action include desensitization of nerve fibres (in the case of capsaicin) and postsynaptic blockade of calcium channels (for gabapentin). In the future, particular histamine receptors, protease pathway molecules, and vanilloids may serve as targets for novel antipruritic agents.

Examining Patient Conceptions: A Case of Metastatic Breast Cancer in an African American Male to Female Transgender Patient

An African American male to female transgender patient treated with estrogen detected a breast lump that was confirmed by her primary care provider. The patient refused mammography and 14 months later she was diagnosed with metastatic breast cancer with spinal cord compression. We used ethnographic interviews and observations to elicit the patient’s conceptions of her illness and actions. The patient identified herself as biologically male and socially female; she thought that the former protected her against breast cancer; she had fears that excision would make a breast tumor spread; and she believed injectable estrogens were less likely than oral estrogens to cause cancer. Analysis suggests dissociation between the patient’s social and biological identities, fear and fatalism around cancer screening, and legitimization of injectable hormones. This case emphasizes the importance of eliciting and interpreting a patient’s conceptions of health and illness when discordant understandings develop between patient and physician.

Defining scholarly activity in graduate medical education.

BACKGROUND Scholarly activity is a requirement for accreditation by the Accreditation Council for Graduate Medical Education. There is currently no uniform definition used by all Residency Review Committees (RRCs). A total of 6 of the 27 RRCs currently have a rubric or draft of a rubric to evaluate scholarly activity. OBJECTIVE To develop a definition of scholarly activity and a set of rubrics to be used in program accreditation to reduce subjectivity of the evaluation of scholarly activity at the level of individual residency programs and across RRCs. METHODS We performed a review of the pertinent literature and selected faculty promotion criteria across the United States to develop a structure for a proposed rubric of scholarly activity, drawing on work on scholarship by experts to create a definition of scholarly activity and rubrics for its assessment. RESULTS The literature review showed that academic institutions in the United States place emphasis on all 4 major components of Boyers definition of scholarship: discovery, integration, application, and teaching. We feel that the assessment of scholarly activity should mirror these findings as set forth in our proposed rubric. Our proposed rubric is intended to ensure a more objective evaluation of these components of scholarship in accreditation reviews, and to address both expectations for scholarly pursuits for core teaching faculty and those for resident and fellow physicians. CONCLUSION The aim of our proposed rubric is to ensure a more objective evaluation of these components of scholarship in accreditation reviews, and to address expectations for scholarly pursuits for core teaching faculty as well as those for resident and fellow physicians.

Cardiac Rupture After Intravenous t-PA Administration in Acute Ischemic Stroke

BackgroundVentricular free wall rupture is a fatal complication of myocardial infarction (MI). Although described in MI patients who receive thrombolytic therapy, this complication is not well known in ischemic stroke patients who receive intravenous (IV) t-PA.MethodsCase report.ResultsWe present a 93-year-old woman with an acute onset of a right middle cerebral artery syndrome in the setting of subacute MI. IV t-PA was administered and she subsequently developed asystolic arrest and died. Autopsy showed subacute MI, hemopericardium, and rupture of the left ventricle.ConclusionsThis case illustrates a fatal cardiac complication of IV thrombolytic therapy for stroke. The speculated mechanism is hemorrhage into the infarcted myocardium.

A randomized trial of hypothesis-driven vs screening neurologic examination

Objective: We hypothesized that trainees would perform better using a hypothesis-driven rather than a traditional screening approach to the neurologic examination. Methods: We randomly assigned 16 medical students to perform screening examinations of all major aspects of neurologic function or hypothesis-driven examinations focused on aspects suggested by the history. Each student examined 4 patients, 2 of whom had focal deficits. Outcomes of interest were the correct identification of patients with focal deficits, number of specific deficits detected, and examination duration. Outcomes were assessed by an investigator blinded to group assignments. The McNemar test was used to compare the sensitivity and specificity of the 2 examination methods. Results: Sensitivity was higher with hypothesis-driven examinations than with screening examinations (78% vs 56%; p = 0.046), although specificity was lower (71% vs 100%; p = 0.046). The hypothesis-driven group identified 61% of specific examination abnormalities, whereas the screening group identified 53% (p = 0.008). Median examination duration was 1 minute shorter in the hypothesis-driven group (7.0 minutes vs 8.0 minutes; p = 0.13). Conclusions: In this randomized trial comparing 2 methods of neurologic examination, a hypothesis-driven approach resulted in greater sensitivity and a trend toward faster examinations, at the cost of lower specificity, compared with the traditional screening approach. Our findings suggest that a hypothesis-driven approach may be superior when the history is concerning for an acute focal neurologic process.

Breaking down silos: mapping growth of cross-disciplinary collaboration in a translational science initiative.

The importance of transdisciplinary collaboration is growing, though not much is known about how to measure collaboration patterns. The purpose of this paper is to present multiple ways of mapping and evaluating the growth of cross‐disciplinary partnerships over time. Social network analysis was used to examine the impact of a Clinical and Translational Science Award (CTSA) on collaboration patterns. Grant submissions from 2007 through 2010 and publications from 2007 through 2011 of Institute of Clinical and Translational Sciences (ICTS) members were examined. A Cohort Model examining the first‐year ICTS members demonstrated an overall increase in collaborations on grants and publications, as well as an increase in cross‐discipline collaboration as compared to within‐discipline. A Growth Model that included additional members over time demonstrated the same pattern for grant submissions, but a decrease in cross‐discipline collaboration as compared to within‐discipline collaboration for publications. ICTS members generally became more cross‐disciplinary in their collaborations during the CTSA. The exception of publications for the Growth Model may be due to the time lag between funding and publication, as well as pressure for younger scientists to publish in their own fields. Network analysis serves as a valuable tool for evaluating changes in scientific collaboration.

Academic Cross-Pollination: The Role of Disciplinary Affiliation in Research Collaboration

Academic collaboration is critical to knowledge production, especially as teams dominate scientific endeavors. Typical predictors of collaboration include individual characteristics such as academic rank or institution, and network characteristics such as a central position in a publication network. The role of disciplinary affiliation in the initiation of an academic collaboration between two investigators deserves more attention. Here, we examine the influence of disciplinary patterns on collaboration formation with control of known predictors using an inferential network model. The study group included all researchers in the Institute of Clinical and Translational Sciences (ICTS) at Washington University in St. Louis. Longitudinal data were collected on co-authorships in grants and publications before and after ICTS establishment. Exponential-family random graph models were used to build the network models. The results show that disciplinary affiliation independently predicted collaboration in grant and publication networks, particularly in the later years. Overall collaboration increased in the post-ICTS networks, with cross-discipline ties occurring more often than within-discipline ties in grants, but not publications. This research may inform better evaluation models of university-based collaboration, and offer a roadmap to improve cross-disciplinary collaboration with discipline-informed network interventions.

Social networks and neurological illness

Every patient is embedded in a social network of interpersonal connections that influence health outcomes. Neurologists routinely need to engage with a patients family and friends due to the nature of the illness and its social sequelae. Social isolation is a potent determinant of poor health and neurobiological changes, and its effects can be comparable to those of traditional risk factors. It would seem reasonable, therefore, to map and follow the personal networks of neurology patients. This approach reveals influential people, their habits, and linkage patterns that could facilitate or limit health behaviours. Personal network information can be particularly valuable to enhance risk factor management, medication adherence, and functional recovery. Here, we propose an agenda for research and clinical practice that includes mapping the networks of patients with diverse neurological disorders, evaluating the impact of the networks on patient outcomes, and testing network interventions.

The practice of poetry among a group of heroin addicts in India: naturalistic peer learning

As part of an ongoing ethnographic study, this paper aims to consider the practice of poetry, sher-o-shayari, as naturalistic peer learning among a group of heroin addicts in Yamuna Bazaar, New Delhi. By examining meanings given to sher-o-shayari and experiences of participating in the practice, this article makes the claim that the practice of poetry involved three learning processes. First, it entailed ‘legitimate peripheral participation’ during group sessions in which implicit performance rules were created, evolved, and transferred to newcomers. Second, it included ‘meaning negotiation’ in which participants ‘break’ and ‘join’ different lines, images, or themes in group improvisation or individual creation events. Third, it contained ‘reflective learning’, which enabled development of the ‘whole’ person and helped situate the individual in the social world. Such data are important for the creation of ‘organic’ peer education programs that utilize naturalistic peer learning mechanisms.

Accuracy of Wearable Cameras to Track Social Interactions in Stroke Survivors.

BACKGROUND Social isolation after a stroke is related to poor outcomes. However, a full study of social networks on stroke outcomes is limited by the current metrics available. Typical measures of social networks rely on self-report, which is vulnerable to response bias and measurement error. We aimed to test the accuracy of an objective measure-wearable cameras-to capture face-to-face social interactions in stroke survivors. If accurate and usable in real-world settings, this technology would allow improved examination of social factors on stroke outcomes. METHODS In this prospective study, 10 stroke survivors each wore 2 wearable cameras: Autographer (OMG Life Limited, Oxford, United Kingdom) and Narrative Clip (Narrative, Linköping, Sweden). Each camera automatically took a picture every 20-30 seconds. Patients mingled with healthy controls for 5 minutes of 1-on-1 interactions followed by 5 minutes of no interaction for 2 hours. After the event, 2 blinded judges assessed whether photograph sequences identified interactions or noninteractions. Diagnostic accuracy statistics were calculated. RESULTS A total of 8776 photographs were taken and adjudicated. In distinguishing interactions, the Autographers sensitivity was 1.00 and specificity was .98. The Narrative Clips sensitivity was .58 and specificity was 1.00. The receiver operating characteristic curves of the 2 devices were statistically different (Z = 8.26, P < .001). CONCLUSIONS Wearable cameras can accurately detect social interactions of stroke survivors. Likely because of its large field of view, the Autographer was more sensitive than the Narrative Clip for this purpose.