Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
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Comparative Study
The prognostic value of evoked responses from primary somatosensory and auditory cortex in comatose patients.
To evaluate somatosensory and auditory primary cortices using somatosensory evoked potentials (SEPs) and middle latency auditory evoked potentials (MLAEPs) in the prognosis of return to consciousness in comatose patients. ⋯ The prognostic value of SEPs and MLAEPs in comatose patients depends on the cause of coma. Measurement of response amplitudes is informative. Abolition of cortical SEPs and/or cortical MLAEPs precludes post-anoxic comatose patients from returning to consciousness (100% specificity). In any case, the presence of short latency cortical somatosensory or auditory components is not a guarantee for return to consciousness. Late components should then be recorded.
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To investigate the effect of conditioning painful stimulation on the early somatosensory magnetic fields (SEF) of test stimulation, in order to clarify the location of the gating effect of pain on tactile response. ⋯ The finding suggested that the touch gate might lie in the thalamus or SI.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of TMJ anesthesia and jaw gape on jaw-stretch reflexes in humans.
To study the roles of afferent sensory inputs in the temporomandibular joint (TMJ) and of muscle length in the modulation of the jaw-stretch reflex in humans. ⋯ Blocking the afferent sensory input (including the mechanoreceptors) from the TMJ seems to have no influence on the sensitivity of the human jaw-stretch reflex. Instead, muscle spindles are the most likely receptors to be responsible for the reflex modulation that was observed in the present study.
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Comparative Study
Intracranial volume conduction of cortical spikes and sleep potentials recorded with deep brain stimulating electrodes.
To examine interictal epileptiform and sleep potentials recorded intracranially from deep brain stimulation (DBS) electrodes in patients treated with DBS for epilepsy. Specifically, this study sought to determine whether the DBS-recorded potentials represent: (a) volume conduction from surface neocortical discharges or (b) transsynaptic propagation along cortical-subcortical pathways with local generation of the subcortical potentials near the DBS targets. ⋯ Detailed analysis of the intracranial potentials recorded from DBS electrodes in association with scalp EEG spikes and sleep discharges shows that the intracranial waveforms represent volume conduction from discharges generated in the neocortex and not, as has been suggested, locally generated activity resulting from cortical-subcortical neural propagation.
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Comparative Study
Changes in median nerve somatosensory transmission and motor output following transient deafferentation of the radial nerve in humans.
To determine if transient anaesthetic deafferentation of the radial nerve would lead to alterations in processing of early somatosensory evoked potentials (SEPs) from the median nerve or alter cortico-motor output to the median nerve innervated abductor pollicis brevis (APB) muscle. ⋯ Transient deafferentation of the radial nerve, which supplies wrist and hand extensor muscles, has been shown to alter sensory processing from and motor output to the median nerve innervated thenar muscles.