Different Learning Curves for Axillary Brachial Plexus Block: Ultrasound Guidance versus Nerve Stimulation

Little is known about the learning of the skills needed to perform ultrasound- or nerve stimulator-guided peripheral nerve blocks. The aim of this study was to compare the learning curves of residents trained in ultrasound guidance versus residents trained in nerve stimulation for axillary brachial plexus block. Ten residents with no previous experience with using ultrasound received ultrasound training and another ten residents with no previous experience with using nerve stimulation received nerve stimulation training. The novices' learning curves were generated by retrospective data analysis out of our electronic anaesthesia database. Individual success rates were pooled, and the institutional learning curve was calculated using a bootstrapping technique in combination with a Monte Carlo simulation procedure. The skills required to perform successful ultrasound-guided axillary brachial plexus block can be learnt faster and lead to a higher final success rate compared to nerve stimulator-guided axillary brachial plexus block.

Biomedical nanoparticles modulate specific CD4+ T cell stimulation by inhibition of antigen processing in dendritic cells

Understanding how nanoparticles may affect immune responses is an essential prerequisite to developing novel clinical applications. To investigate nanoparticle-dependent outcomes on immune responses, dendritic cells (DCs) were treated with model biomedical poly(vinylalcohol)-coated super-paramagnetic iron oxide nanoparticles (PVA-SPIONs). PVA-SPIONs uptake by human monocyte-derived DCs (MDDCs) was analyzed by flow cytometry (FACS) and advanced imaging techniques. Viability, activation, function, and stimulatory capacity of MDDCs were assessed by FACS and an in vitro CD4+ T cell assay. PVA-SPION uptake was dose-dependent, decreased by lipopolysaccharide (LPS)-induced MDDC maturation at higher particle concentrations, and was inhibited by cytochalasin D pre-treatment. PVA-SPIONs did not alter surface marker expression (CD80, CD83, CD86, myeloid/plasmacytoid DC markers) or antigen-uptake, but decreased the capacity of MDDCs to process antigen, stimulate CD4+ T cells, and induce cytokines. The decreased antigen processing and CD4+ T cell stimulation capability of MDDCs following PVA-SPION treatment suggests that MDDCs may revert to a more functionally immature state following particle exposure.

Effects of transcranial direct current stimulation (tDCS) on behaviour and electrophysiology of language production

Excitatory anodal transcranial direct current stimulation (A-tDCS) over the left dorsal prefrontal cortex (DPFC) has been shown to improve language production. The present study examined neurophysiological underpinnings of this effect. In a single-blinded within-subject design, we traced effects of A-tDCS compared to sham stimulation over the left DPFC using electrophysiological and behavioural correlates during overt picture naming. Online effects were examined during A-tDCS by employing the semantic interference (SI-)Effect – a marker that denotes the functional integrity of the language system. The behavioural SI-Effect was found to be reduced, whereas the electrophysiological SI-Effect was enhanced over left compared to right temporal scalp-electrode sites. This modulation is suggested to reflect a superior tuning of neural responses within language-related generators. After -(offline) effects of A-tDCS were detected in the delta frequency band, a marker of neural inhibition. After A-tDCS there was a reduction in delta activity during picture naming and the resting state, interpreted to indicate neural disinhibition. Together, these findings demonstrate electrophysiological modulations induced by A-tDCS of the left DPFC. They suggest that A-tDCS is capable of enhancing neural processes during and after application. The present functional and oscillatory neural markers could detect positive effects of prefrontal A-tDCS, which could be of use in the neuro-rehabilitation of frontal language functions.

In vitro induction of lymph node cell proliferation by mouse bone marrow dendritic cells following stimulation with different Echinococcus multilocularis antigens

The immune response of mice experimentally infected with Echinococcus multilocularis metacestodes becomes impaired so as to allow parasite survival and proliferation. Our study tackled the question on how different classes of E. multilocularis antigens (crude vesicular fluid (VF); purified proteinic rec-14-3-3; purified carbohydrate Em2(G11)) are involved in the maturation process of bone-marrow-derived dendritic cells (BMDCs) and subsequent exposure to lymph node (LN) cells. In our experiments, we used BMDCs cultivated from either naïve (control) or alveolar echinococcosis (AE)-infected C57BL/6 mice. We then tested surface markers (CD80, CD86, MHC class II) and cytokine expression levels (interleukin (IL)-10, IL-12p40 and tumour necrosis factor (TNF)-α) of non-stimulated BMDCs versus BMDCs stimulated with different Em-antigens or lipopolysaccharide (LPS). While LPS and rec-14-3-3-antigen were able to induce CD80, CD86 and (to a lower extent) MHC class II surface expression, Em2(G11) and, strikingly, also VF-antigen failed to do so. Similarly, LPS and rec-14-3-3 yielded elevated IL-12, TNF-α and IL-10 expression levels, while Em2(G11) and VF-antigen didn't. When naïve BMDCs were loaded with VF-antigen, they induced a strong non-specific proliferation of uncommitted LN cells. For both, BMDCs or LN cells, isolated from AE-infected mice, proliferation was abrogated. The most striking difference, revealed by comparing naïve with AE-BMDCs, was the complete inability of LPS-stimulated AE-BMDCs to activate lymphocytes from any LN cell group. Overall, the presenting activity of BMDCs from AE-infected mice seemed to trigger unresponsiveness in T cells, especially in the case of VF-antigen stimulation, thus contributing to the suppression of clonal expansion during the chronic phase of AE infection.

Theta Burst Stimulation Over the Right Broca's Homologue Induces Improvement of Naming in Aphasic Patients

Improvements of language production in aphasic patients have been reported following repeated 1-Hz transcranial magnetic stimulation over the nondamaged right hemisphere. Most studies examined aphasic patients in the chronic phase. The effect of transcranial magnetic stimulation application in acute or subacute patients has not been systematically studied. We aimed to evaluate whether continuous theta burst stimulation, an inhibitory protocol with a shorter application time than the common 1-Hz protocol, is able to improve naming performance in aphasic patients in different poststroke phases.

Local glucocorticoid production in the mouse lung is induced by immune cell stimulation

Glucocorticoids (GC) are potent anti-inflammatory and immunosuppressive steroid hormones, mainly produced by the adrenal glands. However, increasing evidence supports the idea of additional extra-adrenal sources of bioactive GC. The lung epithelium is constantly exposed to a plethora of antigenic stimuli, and local GC synthesis could contribute to limit uncontrolled immune reactions and tissue damage.

Theta burst stimulation reduces disability during the activities of daily living in spatial neglect

Left-sided spatial neglect is a common neurological syndrome following right-hemispheric stroke. The presence of spatial neglect is a powerful predictor of poor rehabilitation outcome. In one influential account of spatial neglect, interhemispheric inhibition is impaired and leads to a pathological hyperactivity in the contralesional hemisphere, resulting in a biased attentional allocation towards the right hemifield. Inhibitory transcranial magnetic stimulation can reduce the hyperactivity of the contralesional, intact hemisphere and thereby improve spatial neglect symptoms. However, it is not known whether this improvement is also relevant to the activities of daily living during spontaneous behaviour. The primary aim of the present study was to investigate whether the repeated application of continuous theta burst stimulation trains could ameliorate spatial neglect on a quantitative measure of the activities of daily living during spontaneous behaviour. We applied the Catherine Bergego Scale, a standardized observation questionnaire that can validly and reliably detect the presence and severity of spatial neglect during the activities of daily living. Eight trains of continuous theta burst stimulation were applied over two consecutive days on the contralesional, left posterior parietal cortex in patients suffering from subacute left spatial neglect, in a randomized, double-blind, sham-controlled design, which also included a control group of neglect patients without stimulation. The results showed a 37% improvement in the spontaneous everyday behaviour of the neglect patients after the repeated application of continuous theta burst stimulation. Remarkably, the improvement persisted for at least 3 weeks after stimulation. The amelioration of spatial neglect symptoms in the activities of daily living was also generally accompanied by significantly better performance in the neuropsychological tests. No significant amelioration in symptoms was observed after sham stimulation or in the control group without stimulation. These results provide Class I evidence that continuous theta burst stimulation is a viable add-on therapy in neglect rehabilitation that facilitates recovery of normal everyday behaviour.

Stimulation of the subthalamic nucleus at an earlier disease stage of Parkinson's disease: Concept and standards of the EARLYSTIM-study

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established treatment for advanced Parkinson's disease (PD) with disabling motor complications. However, stimulation may be beneficial at an earlier stage of PD when motor fluctuations and dyskinesia are only mild and psychosocial competence is still maintained. The EARLYSTIM trial was conducted in patients with recent onset of levodopa-induced motor complications (<3 years) whose social and occupational functioning remained preserved. This is called 'early' here. The study was a randomized, multicenter, bi-national pivotal trial with a 2 year observation period. Quality of life was the main outcome measure, and a video-based motor score was a blinded secondary outcome of the study. Motor, neuropsychological, psychiatric and psychosocial aspects were captured by established scales and questionnaires. The patient group randomized here is the earliest in the disease course and the youngest recruited in controlled DBS trials so far. The methodological innovation for DBS-studies of this study lies in novel procedures developed and used for monitoring best medical treatment, neurosurgical consistency, best management of stimulation programming, blinded video assessment of motor disability, and prevention of suicidal behaviors.

Muscle velocity recovery cycles: effects of repetitive stimulation on two muscles

We sought to characterize the excitability properties of tibialis anterior (TA) and brachioradialis (BR) muscles at rest and during electrically induced muscle activation in normal subjects.

Cerebral blood flow identifies responders to transcranial magnetic stimulation in auditory verbal hallucinations

Auditory hallucinations comprise a critical domain of psychopathology in schizophrenia. Repetitive transcranial magnetic stimulation (TMS) has shown promise as an intervention with both positive and negative reports. The aim of this study was to test resting-brain perfusion before treatment as a possible biological marker of response to repetitive TMS. Twenty-four medicated patients underwent resting-brain perfusion magnetic resonance imaging with arterial spin labeling (ASL) before 10 days of repetitive TMS treatment. Response was defined as a reduction in the hallucination change scale of at least 50%. Responders (n=9) were robustly differentiated from nonresponders (n=15) to repetitive TMS by the higher regional cerebral blood flow (CBF) in the left superior temporal gyrus (STG) (P<0.05, corrected) before treatment. Resting-brain perfusion in the left STG predicted the response to repetitive TMS in this study sample, suggesting this parameter as a possible bio-marker of response in patients with schizophrenia and auditory hallucinations. Being noninvasive and relatively easy to use, resting perfusion measurement before treatment might be a clinically relevant way to identify possible responders and nonresponders to repetitive TMS.

Reduced neuronal activity in language-related regions after transcranial magnetic stimulation therapy for auditory verbal hallucinations

Transcranial magnetic stimulation (TMS) is a novel therapeutic approach, used in patients with pharmacoresistant auditory verbal hallucinations (AVH). To investigate the neurobiological effects of TMS on AVH, we measured cerebral blood flow with pseudo-continuous magnetic resonance-arterial spin labeling 20 ± 6 hours before and after TMS treatment.