Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
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Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are non-invasive methods of brain stimulation (NIBS) that can induce significant effects on cortical and subcortical neural networks. Both methods are relatively safe if appropriate guidelines are followed, and both can exert neuromodulatory effects that may be applied to the investigation of the autonomic nervous system (ANS). In addition, ANS measures can shed important light onto the neurobiologic mechanisms of NIBS. ⋯ We structure our findings into four broad (not mutually exclusive) categories: (i) studies in which ANS function was modified by NIBS versus those in which it was not; (ii) studies in which NIBS was used to understand ANS function, (iii) studies in which ANS was used to understand NIBS mechanisms and (iv) NIBS/ANS studies conducted in healthy subjects versus those in patients with neuropsychiatric diseases. Forty-four articles were identified and no conclusive evidence of the effects of NIBS on ANS was observed, mainly because of the heterogeneity of included studies. Based on a comprehensive summary of this literature we propose how NIBS might be further developed to enhance our understanding of the cortical mechanisms of autonomic regulation and perhaps to modulate autonomic activity for therapeutic purposes.
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Controlled Clinical Trial
Modulation of laser-evoked potentials and pain perception by transcutaneous electrical nerve stimulation (TENS): a placebo-controlled study in healthy volunteers.
To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on brain nociceptive responses (laser-evoked potentials, LEPs) and pain perception. ⋯ This modulation of subjective and objective concomitants of pain processing reflects a real neurophysiological TENS-related effect on nociceptive transmission.
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Ultrasound measurements of the cross sectional area (CSA) variability have been recently introduced to quantify pathological changes in peripheral nerves (PN). ⋯ The new CSA variability measures may be helpful in investigating pathologies of the PN.
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Case Reports
Myopathic EMG findings and type II muscle fiber atrophy in patients with Lambert-Eaton myasthenic syndrome.
Lambert-Eaton myasthenic syndrome (LEMS) is a rare condition, which may mimic myopathy. A few reports have described that EMG in LEMS may show changes compatible with myopathy, and muscle biopsies have been described with type II as well as type I atrophy. The EMG results were, however, based on qualitative EMG examination and the histopathological methods were not always clear. The objective of this study was to investigate if the previous EMG findings could be confirmed with quantitative EMG (QEMG) and to describe muscle histology in LEMS. ⋯ LEMS is a debilitating, but treatable disease, which often precedes detection of a malignancy and it is therefore of obvious importance to diagnose these patients with speed and certainty. Hence it is important that neurophysiologists and neurologists are aware that EMG and histological abnormalities mimicking myopathy may be found in LEMS patients so that these findings do not prolong or misdirect the diagnostic process in these patients.