Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
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This was to demonstrate the ability to electrodiagnosed mild lower brachial plexus lesion only through abnormal medial antebrachial cutaneous nerve (MABCN) conduction study. ⋯ These 16 cases, support a new electrodiagnostic pattern to define a mild lower brachial plexus lesion: comparatively low or low MABCN SNAP amplitude, normal median and ulnar SNAP/Compound motor action potential amplitudes and normal or slightly reduced interference pattern in some C8-T1 innervated muscles. This pattern can be found in patients with 'carpal tunnel syndrome like' symptoms who have normal electro-diagnostic examination, or in patients with clinical features suggesting a lower brachial plexus lesion.
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Much effort has been devoted to the search for the neurophysiological correlates of implicit memory. A commonly held view is that the early portion (250-500 ms) of the event-related potential (ERP) word repetition effect reflects processes important for perceptual implicit memory whereas the latter portion reflects processes implicated in explicit memory. It is, however, difficult to disentangle with certainty the relative contributions of each form of memory on ERPs since both forms co-exist in normal subjects. To dissociate ERP effect related to implicit and explicit memory, we used isoflurane sedation in normal subjects to suppress explicit remembering while sparing implicit memory. These ERPs were compared with those of non-medicated control subjects. ⋯ The present study shows that the reversible alterations of memory by general anesthetics can be used to study the neurophysiological correlates of memory processes.
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Use the tendon reflex to examine spinal cord excitability after acute spinal cord injury (SCI), relating excitability findings to prognosis. ⋯ Taken together, tendon response amplitude and reflex spread were sensitive and specific indicators of preserved supraspinal control over lower limb musculature in subjects with acute SCI. A simple algorithm using these outcome measures predicted a 'motor-complete' status with 100% accuracy, and a motor-incomplete status with accuracy exceeding 91%.
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Randomized Controlled Trial Clinical Trial
The role of sensory and motor evoked potentials in the prognosis of Pott's paraplegia.
In view of paucity of evoked potential changes in Pott's paraplegia, it is proposed to evaluate the role of motor and somatosensory evoked potentials in predicting the outcome. ⋯ MEP and SEP both are helpful in predicting 6-month outcome. Combining SEP and MEP gives stronger correlation with 6-month outcome compared to only MEP or SEP. The potential role of evoked potentials in deciding different therapeutic strategies needs further studies.
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Comparative Study
The refractory period of fast conducting corticospinal tract axons in man and its implications for intraoperative monitoring of motor evoked potentials.
To determine the absolute and relative refractory period (RRP) of fast conducting axons of the corticospinal tract in response to paired high intensity (HI or supramaximal) and moderate intensity (MI or submaximal) electrical stimuli. The importance of the refractory period of fast conducting corticospinal tract axons has to be considered if repetitive transcranial electrical stimulation (TES) is to be effective for eliciting motor evoked potentials (MEPs) intraoperatively. ⋯ The recovery of D wave amplitude is dependent upon stimulus intensity. High intensity produces fast recovery. This is an important factor for the generation of MEPs. When HI TES is used to elicit MEPs, short and long ISIs are equally effective. When MI TES is used to elicit MEPs, only a long ISI of 4 ms is effective.