Articles: human.
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Am. J. Respir. Crit. Care Med. · Jan 2014
Clinical TrialLong-Term Facilitation of Ventilation in Humans with Chronic Spinal Cord Injury.
Intermittent stimulation of the respiratory system with hypoxia causes persistent increases in respiratory motor output (i.e., long-term facilitation) in animals with spinal cord injury. This paradigm, therefore, has been touted as a potential respiratory rehabilitation strategy. ⋯ Ventilatory long-term facilitation can be evoked by brief periods of hypoxia in humans with chronic spinal cord injury. Thus, intermittent hypoxia may represent a strategy for inducing respiratory neuroplasticity after declines in respiratory function that are related to neurological impairment. Clinical trial registered with www.clinicaltrials.gov (NCT01272011).
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Developmental neocortical malformations resulting from abnormal neurogenesis, disturbances in programmed cell death, or neuronal migration disorders may cause a long-term hyperexcitability. Early generated Cajal-Retzius and subplate neurons play important roles in transient cortical circuits, and structural/functional disorders in early cortical development may induce persistent network disturbances and epileptic disorders. In particular, depolarizing GABAergic responses are important for the regulation of neurodevelopmental events, like neurogenesis or migration, while pathophysiological alterations in chloride homeostasis may cause epileptic activity. ⋯ The neocortical focus may be surrounded by widespread molecular, structural, and functional disturbances, which are difficult to recognize with imaging technologies. However, modern imaging and electrophysiological techniques enable focused hypotheses of the neocortical epileptogenic zone, thus allowing more specific epilepsy surgery. Focal cortical malformation can be successfully removed with minimal rim, close to or even within eloquent cortex with a promising risk-benefit ratio.
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Front Behav Neurosci · Jan 2014
Touch perceptions across skin sites: differences between sensitivity, direction discrimination and pleasantness.
Human skin is innervated with different tactile afferents, which are found at varying densities over the body. We investigate how the relationships between tactile pleasantness, sensitivity and discrimination differ across the skin. Tactile pleasantness was assessed by stroking a soft brush over the skin, using five velocities (0.3, 1, 3, 10, 30 cm s(-1)), known to differentiate hedonic touch, and pleasantness ratings were gained. ⋯ Tactile sensitivity and discrimination levels also correlated significantly, although the tactile acuity did not relate to the perceived pleasantness of touch. Tactile pleasantness varied in a subtle way across skin sites, where the middle velocities were always rated as the most pleasant, but the ratings at hairy skin sites were more receptive to changes in stroking velocity. We postulate that although the mechanoreceptive afferent physiology may be different over the skin, the perception of pleasant touch can be interpreted using all of the available incoming somatosensory information in combination with central processing.
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Restor. Neurol. Neurosci. · Jan 2014
Comparative StudyIncreasing human leg motor cortex excitability by transcranial high frequency random noise stimulation.
Transcranial random noise stimulation (tRNS) can increase the excitability of hand area of the primary motor cortex (M1). The aim of this study was to compare the efficacy of tRNS and transcranial direct current stimulation (tDCS) on the leg motor cortex. ⋯ Our results suggest that although the leg area has a deeper position in the cortex compared to the hand area, it can be reached by weak transcranial currents. Both anodal tDCS and tRNS had comparable effect on cortical excitability.
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Stud Health Technol Inform · Jan 2014
Validation of a computerized technique for automatically tracking and measuring the inferior vena cava in ultrasound imagery.
Accurate resuscitation of the critically-ill patient using intravenous fluids and blood products is a challenging, time sensitive task. Ultrasound of the inferior vena cava (IVC) is a non-invasive technique currently used to guide fluid administration, though multiple factors such as variable image quality, time, and operator skill challenge mainstream acceptance. ⋯ Addressing problems such as gaps in the vessel wall and intra-lumen speckle should result in improved performance in average and poor quality videos. Semi-automated measurement of the IVC for the purposes of non-invasive estimation of circulating blood volume poses challenges however is feasible.