1,663,448 research outputs found

    Massage Stimulation Reduces Tumor Necrotic Factor-alpha and Interleukin-6 in Preterm, Low Birth Weight with Appropriate Gestational Age Newborns

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    Preterm newborn is susceptible from various stresses such as infections or non infections. During stress, immune response is activated by synthesizing and releasing of cytokines from activated immune cells into the circulation. One of the efforts to overcome the stress is massage stimulation. Several studies have been carried out to find out the benefit of massage stimulation. The objective of this study is to find out the effect of massage stimulation to reduce of TNF-? and IL-6 levels on preterm, low birth weight, appropriate to gestational age newborn. This was a randomized controlled trial. Subjects of the study were all preterm newborns with a stable medical condition, birth weight 1,500-2,499 gram, appropriate to gestational age. The study was carried out on October-December 2011, in neonatology ward, Sanglah General Hospital, Vali-Indonesia. The number of cases was 35 subjects and the number of controls was 36 subjects. The examination of TNF-?, IL-6 levels and birth weights before and after massage stimulation were performed on both groups. The level of TNF-? and IL-6 was examined by applying ELISA method. The level of confidence was ? = 0.05. All statistical analysis was performed by computer programme. There was different level of cytokine pro-inflammation TNF-? (p=0.025) and IL-6 (p=0,001) comparing before and after condition massage stimulation. Outcome of body weight were also different at before and after massage stimulation, with p value 0.042. The conclusion of this study is that massage stimulation can reduce the level of TNF-?, IL-6 and increasing of birth weight on preterm, low birth weight appropriate gestational age newborn. Based on this study, in the future, massage stimulation can be done in newborn with stable medical conditions by parents or trained staffs

    Towards a computational model for stimulation of the Pedunculopontine nucleus

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    The pedunculopontine nucleus (PPN) has recently been suggested as a new therapeutic target for deep brain stimulation (DBS) in patients suffering from Parkinson's disease, particularly those with severe gait and postural impairment [1]. Stimulation at this site is typically delivered at low frequencies in contrast to the high frequency stimulation required for therapeutic benefit in the subthalamic nucleus (STN) [1]. Despite real therapeutic successes, the fundamental physiological mechanisms underlying the effect of DBS are still not understood. A hypothesis is that DBS masks the pathological synchronized firing patterns of the basal ganglia that characterize the Parkinsonian state with a regularized firing pattern. It remains unclear why stimulation of PPN should be applied with low frequency in contrast to the high frequency stimulation of STN. To get a better understanding of PPN stimulation we construct a computational model for the PPN Type I neurons in a network

    Modality-specific Affective Responses and their Implications for Affective BCI

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    Reliable applications of multimodal affective brain-computer interfaces (aBCI) require a detailed understanding of the processes involved in emotions. To explore the modality-specific nature of affective responses, we studied neurophysiological responses of 24 subjects during visual, auditory, and audiovisual affect stimulation and obtained their subjective ratings. Coherent with literature, we found modality-specific responses in the EEG: parietal alpha power decreases during visual stimulation and increases during auditory stimulation, whereas more anterior alpha power decreases during auditory stimulation and increases during visual stimulation. We discuss the implications of these results for multimodal aBCI

    Deep brain and cortical stimulation for epilepsy

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    Background : Despite optimal medical treatment, including epilepsy surgery, many epilepsy patients have uncontrolled seizures. In the last decades, interest has grown in invasive intracranial neurostimulation as a treatment for these patients. Intracranial stimulation includes both deep brain stimulation (DBS) (stimulation through depth electrodes) and cortical stimulation (subdural electrodes). Objectives : To assess the efficacy, safety and tolerability of deep brain and cortical stimulation for refractory epilepsy based on randomized controlled trials. Search methods : We searched PubMed (6 August 2013), the Cochrane Epilepsy Group Specialized Register (31 August 2013), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 7 of 12) and reference lists of retrieved articles. We also contacted device manufacturers and other researchers in the field. No language restrictions were imposed. Selection criteria : Randomized controlled trials (RCTs) comparing deep brain or cortical stimulation to sham stimulation, resective surgery or further treatment with antiepileptic drugs. Data collection and analysis : Four review authors independently selected trials for inclusion. Two review authors independently extracted the relevant data and assessed trial quality and overall quality of evidence. The outcomes investigated were seizure freedom, responder rate, percentage seizure frequency reduction, adverse events, neuropsychological outcome and quality of life. If additional data were needed, the study investigators were contacted. Results were analysed and reported separately for different intracranial targets for reasons of clinical heterogeneity. Main results : Ten RCTs comparing one to three months of intracranial neurostimulation to sham stimulation were identified. One trial was on anterior thalamic DBS (n = 109; 109 treatment periods); two trials on centromedian thalamic DBS (n = 20; 40 treatment periods), but only one of the trials (n = 7; 14 treatment periods) reported sufficient information for inclusion in the quantitative meta-analysis; three trials on cerebellar stimulation (n = 22; 39 treatment periods); three trials on hippocampal DBS (n = 15; 21 treatment periods); and one trial on responsive ictal onset zone stimulation (n = 191; 191 treatment periods). Evidence of selective reporting was present in four trials and the possibility of a carryover effect complicating interpretation of the results could not be excluded in 4 cross-over trials without any washout period. Moderate-quality evidence could not demonstrate statistically or clinically significant changes in the proportion of patients who were seizure-free or experienced a 50% or greater reduction in seizure frequency (primary outcome measures) after 1 to 3 months of anterior thalamic DBS in (multi) focal epilepsy, responsive ictal onset zone stimulation in (multi) focal epilepsy patients and hippocampal DBS in (medial) temporal lobe epilepsy. However, a statistically significant reduction in seizure frequency was found for anterior thalamic DBS (-17.4% compared to sham stimulation; 95% confidence interval (CI) -32.1 to -1.0; high-quality evidence), responsive ictal onset zone stimulation (-24.9%; 95% CI -40.1 to 6.0; high-quality evidence)) and hippocampal DBS (-28.1%; 95% CI -34.1 to -22.2; moderate-quality evidence). Both anterior thalamic DBS and responsive ictal onset zone stimulation do not have a clinically meaningful impact on quality life after three months of stimulation (high-quality evidence). Electrode implantation resulted in asymptomatic intracranial haemorrhage in 3% to 4% of the patients included in the two largest trials and 5% to 13% had soft tissue infections; no patient reported permanent symptomatic sequelae. Anterior thalamic DBS was associated with fewer epilepsy-associated injuries (7.4 versus 25.5%; P = 0.01) but higher rates of self-reported depression (14.8 versus 1.8%; P = 0.02) and subjective memory impairment (13.8 versus 1.8%; P = 0.03); there were no significant differences in formal neuropsychological testing results between the groups. Responsive ictal-onset zone stimulation was well tolerated with few side effects but SUDEP rate should be closely monitored in the future (4 per 340 [= 11.8 per 1000] patient-years; literature: 2.2-10 per 1000 patient-years). The limited number of patients preclude firm statements on safety and tolerability of hippocampal DBS. With regards to centromedian thalamic DBS and cerebellar stimulation, no statistically significant effects could be demonstrated but evidence is of only low to very low quality. Authors' conclusions : Only short term RCTs on intracranial neurostimulation for epilepsy are available. Compared to sham stimulation, one to three months of anterior thalamic DBS ((multi) focal epilepsy), responsive ictal onset zone stimulation ((multi) focal epilepsy) and hippocampal DBS (temporal lobe epilepsy) moderately reduce seizure frequency in refractory epilepsy patients. Anterior thalamic DBS is associated with higher rates of self-reported depression and subjective memory impairment. SUDEP rates require careful monitoring in patients undergoing responsive ictal onset zone stimulation. There is insufficient evidence to make firm conclusive statements on the efficacy and safety of hippocampal DBS, centromedian thalamic DBS and cerebellar stimulation. There is a need for more, large and well-designed RCTs to validate and optimize the efficacy and safety of invasive intracranial neurostimulation treatments

    Quantifying Performance of Bipedal Standing with Multi-channel EMG

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    Spinal cord stimulation has enabled humans with motor complete spinal cord injury (SCI) to independently stand and recover some lost autonomic function. Quantifying the quality of bipedal standing under spinal stimulation is important for spinal rehabilitation therapies and for new strategies that seek to combine spinal stimulation and rehabilitative robots (such as exoskeletons) in real time feedback. To study the potential for automated electromyography (EMG) analysis in SCI, we evaluated the standing quality of paralyzed patients undergoing electrical spinal cord stimulation using both video and multi-channel surface EMG recordings during spinal stimulation therapy sessions. The quality of standing under different stimulation settings was quantified manually by experienced clinicians. By correlating features of the recorded EMG activity with the expert evaluations, we show that multi-channel EMG recording can provide accurate, fast, and robust estimation for the quality of bipedal standing in spinally stimulated SCI patients. Moreover, our analysis shows that the total number of EMG channels needed to effectively predict standing quality can be reduced while maintaining high estimation accuracy, which provides more flexibility for rehabilitation robotic systems to incorporate EMG recordings

    Electrode geometry and preferential stimulation of spinal nerve fibers having different orientations: a modeling study

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    In a computer modeling study of epidural spinal cord stimulation using a longitudinal array of electrode contacts, the effect of contact geometry and contact combination on the threshold voltages for stimulation of dorsal column (DC) fibers and dorsal root (DR) fibers was investigated. It was concluded that DC-fiber stimulation will be favoured when a tripolar combination and small contact length and spacing are used, while DR-fiber stimulation will be favoured when unipolar stimulation and large contact length are used

    Comparison of stimulation patterns for FES-cycling using measures of oxygen cost and stimulation cost

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    <b>Aim</b><p></p> The energy efficiency of FES-cycling in spinal cord injured subjects is very much lower than that of normal cycling, and efficiency is dependent upon the parameters of muscle stimulation. We investigated measures which can be used to evaluate the effect on cycling performance of changes in stimulation parameters, and which might therefore be used to optimise them. We aimed to determine whether oxygen cost and stimulation cost measurements are sensitive enough to allow discrimination between the efficacy of different activation ranges for stimulation of each muscle group during constant-power cycling. <p></p> <b>Methods</b><p></p> We employed a custom FES-cycling ergometer system, with accurate control of cadence and stimulated exercise workrate. Two sets of muscle activation angles (“stimulation patterns”), denoted “P1” and “P2”, were applied repeatedly (eight times each) during constant-power cycling, in a repeated measures design with a single paraplegic subject. Pulmonary oxygen uptake was measured in real time and used to determine the oxygen cost of the exercise. A new measure of stimulation cost of the exercise is proposed, which represents the total rate of stimulation charge applied to the stimulated muscle groups during cycling. A number of energy-efficiency measures were also estimated. <p></p> <b>Results</b><p></p> Average oxygen cost and stimulation cost of P1 were found to be significantly lower than those for P2 (paired <i>t</i>-test, <i>p</i> < 0.05): oxygen costs were 0.56 ± 0.03 l min<sup>−1</sup> and 0.61 ± 0.04 l min<sup>−1</sup>(mean ± S.D.), respectively; stimulation costs were 74.91 ± 12.15 mC min<sup>−1</sup> and 100.30 ± 14.78 mC min<sup>−1</sup> (mean ± S.D.), respectively. Correspondingly, all efficiency estimates for P1 were greater than those for P2. <p></p> <b>Conclusion</b><p></p> Oxygen cost and stimulation cost measures both allow discrimination between the efficacy of different muscle activation patterns during constant-power FES-cycling. However, stimulation cost is more easily determined in real time, and responds more rapidly and with greatly improved signal-to-noise properties than the ventilatory oxygen uptake measurements required for estimation of oxygen cost. These measures may find utility in the adjustment of stimulation patterns for achievement of optimal cycling performance. <p></p&gt

    Electrical safety in spinal cord stimulation: current density analysis by computer modeling

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    The possibility of tissue damage in spinal cord stimulation was investigated in a computer modeling study. A decrease of the electrode area in monopolar stimulation resulted in an increase of the current density at the electrode surface. When comparing the modeling results with experimental data from literature, it was concluded that even with a small electrode area (0.7 mm2) tissue damage in spinal cord stimulation is improbabl

    The effects of repetitive electric cardiac stimulation in dogs with normal hearts, complete heart block and experimental cardiac arrest

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    Direct cardiac stimulation was conducted in the open chest. In normal animals, auricular stimulation at frequencies faster than the spontaneous rate caused little change in vascular pressures or cardiac output. Comparable ventricular stimulation in the same animals caused falls in cardiac output and blood pressure, with elevations in venous pressure. In contrast, ventricular stimulation in animals with complete heart block caused elevations in cardiac output and blood pressure, and declines in venous pressure. A study was also made of repetitive stimulation in experimental cardiac arrest. Occasionally pacemaking was of value in the resuscitation, but in most cases effective contractions could not be induced with stimulation
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