40 research outputs found

    Microstimulation of human somatosensory cortex evokes task-dependent, spatially patterned responses in motor cortex

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    The primary motor (M1) and somatosensory (S1) cortices play critical roles in motor control but the signaling between these structures is poorly understood. To fill this gap, we recorded – in three participants in an ongoing human clinical trial (NCT01894802) for people with paralyzed hands – the responses evoked in the hand and arm representations of M1 during intracortical microstimulation (ICMS) in the hand representation of S1. We found that ICMS of S1 activated some M1 neurons at short, fixed latencies consistent with monosynaptic activation. Additionally, most of the ICMS-evoked responses in M1 were more variable in time, suggesting indirect effects of stimulation. The spatial pattern of M1 activation varied systematically: S1 electrodes that elicited percepts in a finger preferentially activated M1 neurons excited during that finger’s movement. Moreover, the indirect effects of S1 ICMS on M1 were context dependent, such that the magnitude and even sign relative to baseline varied across tasks. We tested the implications of these effects for brain-control of a virtual hand, in which ICMS conveyed tactile feedback. While ICMS-evoked activation of M1 disrupted decoder performance, this disruption was minimized using biomimetic stimulation, which emphasizes contact transients at the onset and offset of grasp, and reduces sustained stimulation

    Why don't hospital staff activate the rapid response system (RRS)? How frequently is it needed and can the process be improved?

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    Abstract Background The rapid response system (RRS) is a process of accessing help for health professionals when a patient under their care becomes severely ill. Recent studies and meta-analyses show a reduction in cardiac arrests by a one-third in hospitals that have introduced a rapid response team, although the effect on overall hospital mortality is less clear. It has been suggested that the difficulty in establishing the benefit of the RRS has been due to implementation difficulties and a reluctance of clinical staff to call for additional help. This assertion is supported by the observation that patients continue to have poor outcomes in our institution despite an established RRS being available. In many of these cases, the patient is often unstable for many hours or days without help being sought. These poor outcomes are often discovered in an ad hoc fashion, and the real numbers of patients who may benefit from the RRS is currently unknown. This study has been designed to answer three key questions to improve the RRS: estimate the scope of the problem in terms of numbers of patients requiring activation of the RRS; determine cognitive and socio-cultural barriers to calling the Rapid Response Team; and design and implement solutions to address the effectiveness of the RRS. Methods The extent of the problem will be addressed by establishing the incidence of patients who meet abnormal physiological criteria, as determined from a point prevalence investigation conducted across four hospitals. Follow-up review will determine if these patients subsequently require intensive care unit or critical care intervention. This study will be grounded in both cognitive and socio-cultural theoretical frameworks. The cognitive model of situation awareness will be used to determine psychological barriers to RRS activation, and socio-cultural models of interprofessional practice will be triangulated to inform further investigation. A multi-modal approach will be taken using reviews of clinical notes, structured interviews, and focus groups. Interventions will be designed using a human factors analysis approach. Ongoing surveillance of adverse outcomes and surveys of the safety climate in the clinical areas piloting the interventions will occur before and after implementation

    Retro-trochanteric sciatica-like pain: current concept

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    The aim of this manuscript is to review the current knowledge in terms of retro-trochanteric pain syndrome, make recommendations for diagnosis and differential diagnosis and offer suggestions for treatment options. The terminology in the literature is confusing and these symptoms can be referred to as ‘greater trochanteric pain syndrome’, ‘trochanteric bursitis’ and ‘trochanteritis’, among other denominations. The authors focus on a special type of sciatica, i.e. retro-trochanteric pain radiating down to the lower extremity. The impact of different radiographic assessments is discussed. The authors recommend excluding pathology in the spine and pelvic area before following their suggested treatment algorithm for sciatica-like retro-trochanteric pain. Level of evidence II

    Assessing the Quality of Clinical Teachers: A Systematic Review of Content and Quality of Questionnaires for Assessing Clinical Teachers

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    BACKGROUND: Learning in a clinical environment differs from formal educational settings and provides specific challenges for clinicians who are teachers. Instruments that reflect these challenges are needed to identify the strengths and weaknesses of clinical teachers. OBJECTIVE: To systematically review the content, validity, and aims of questionnaires used to assess clinical teachers. DATA SOURCES: MEDLINE, EMBASE, PsycINFO and ERIC from 1976 up to March 2010. REVIEW METHODS: The searches revealed 54 papers on 32 instruments. Data from these papers were documented by independent researchers, using a structured format that included content of the instrument, validation methods, aims of the instrument, and its setting. Results : Aspects covered by the instruments predominantly concerned the use of teaching strategies (included in 30 instruments), supporter role (29), role modeling (27), and feedback (26). Providing opportunities for clinical learning activities was included in 13 instruments. Most studies referred to literature on good clinical teaching, although they failed to provide a clear description of what constitutes a good clinical teacher. Instrument length varied from 1 to 58 items. Except for two instruments, all had to be completed by clerks/residents. Instruments served to provide formative feedback ( instruments) but were also used for resource allocation, promotion, and annual performance review (14 instruments). All but two studies reported on internal consistency and/or reliability; other aspects of validity were examined less frequently. CONCLUSIONS: No instrument covered all relevant aspects of clinical teaching comprehensively. Validation of the instruments was often limited to assessment of internal consistency and reliability. Available instruments for assessing clinical teachers should be used carefully, especially for consequential decisions. There is a need for more valid comprehensive instruments

    Minimally destructive sampling of type specimens of Pyropia (Bangiales, Rhodophyta) recovers complete plastid and mitochondrial genomes

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    The article of record as published may be found at http://dx.doi.org/10.1038/srep05113Plant species, including algae and fungi, are based on type specimens to which the name of a taxon is permanently attached. Applying a scientific name to any specimen therefore requires demonstrating correspondence between the type and that specimen. Traditionally, identifications are based on morpho-anatomical characters, but recently systematists are using DNA sequence data. These studies are flawed if the DNA is isolated from misidentified modern specimens. We propose a genome-based solution. Using 434 mm2 of material from type specimens, we assembled 14 plastid and 15 mitochondrial genomes attributed to the red algae Pyropia perforata, Py. fucicola, and Py. kanakaensis. The chloroplast genomes were fairly conserved, but the mitochondrial genomes differed significantly among populations in content and length. Complete genomes are attainable from 19th and early 20th century type specimens; this validates the effort and cost of their curation as well as supports the practice of the type method
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