Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
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Low amplitude vibration of forearm or hand muscles predominantly activates proprioceptive inputs that influence corticospinal projections in a focal manner, increasing output to the stimulated muscle while reducing output to neighbouring muscles. Modulation of contralateral forearm muscles by vibration has also been reported on one occasion. The aim of the current investigation was to investigate the effects of proprioceptive input from a hand muscle on corticospinal excitability, intracortical inhibition (SICI) and interhemispheric inhibition (IHI) targeting the homologous contralateral muscle. ⋯ These results suggest that sensory input can modulate excitability in both motor cortices simultaneously, as well as the relationship between them. Interventions which modulate this transcallosal relationship may become useful in disorders where abnormal IHI is a potential therapeutic target.
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To compare spectral and complexity characteristics of the EEG in a unique case of subcortical infarct to those seen in healthy controls. ⋯ Complexity indices of the EEG are sensitive complementary measures of electrophysiological changes caused by local lesions such as subcortical stroke.
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To investigate the effects of hyperglycemia on persistent Na+ currents in human diabetic nerves, eliminating the factors of passive membrane properties as a factor. Previous studies show that strength-duration time constant of a nerve is shortened under hyperglycemia, suggesting reduced axonal persistent Na+ currents. However, the time constant is also affected by changes in passive membrane properties. Latent addition using computerized threshold tracking is a new method that can separately evaluate Na+ currents and passive membrane properties. ⋯ Reduced nodal Na+ currents may partly contribute to the pathophysiology of human diabetic neuropathy.
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To investigate the effect of psychological arousal on pain ratings and the R2 component of the electrically evoked blink reflex to a 'pure' noiciceptive stimulus. ⋯ Supra-spinal influences need to be considered during clinical evaluation of the trigeminal nociceptive blink reflex.