Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Apr 2012
ReviewIntraoperative use of somatosensory-evoked potential in monitoring nerve roots.
Different intraoperative neuromonitoring modalities (mixed-nerve somatosensory-evoked potential [M-SSEP], dermatomal somatosensory-evoked potential [D-SSEP], compound motor-evoked potential [CMEP], electromyography [EMG], and the Hoffmann reflex [H-reflex]) have been developed for early detection of nerve root injury, for timely revision, and for damage reduction. In this study, we discuss the advantages and disadvantages of M-SSEP and D-SSEP by reviewing experimental evidence from animal models and clinical practice.
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J Clin Neurophysiol · Apr 2012
ReviewUtility of motor evoked potentials for intraoperative nerve root monitoring.
There is no entirely satisfactory way to monitor nerve root integrity during spinal surgery. In particular, standard free-running electromyography carries a high false-positive rate and some false-negative rate of injury. Stimulated electromyography to direct root stimulation can only be done intermittently, and roots are often inaccessible. ⋯ Only amplitude reduction warning criteria have been studied, but no percentage cutoff consensus has emerged, and this approach is troubled by response variability. There is some evidence that MEPs might reduce false electromyographic results. In conclusion, muscle MEPs could compliment electromyography but seem unlikely to completely solve the problem of nerve root monitoring.
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J Clin Neurophysiol · Apr 2012
Ulnar neuropathy in hansen disease: clinical, high-resolution ultrasound and electrophysiologic correlations.
To assess the relationship between the cross-sectional area (CSA) of the ulnar nerve by ultrasound (US) with clinical and electrophysiologic findings in Hansen ulnar neuropathy. ⋯ In leprosy patients, a positive correlation exits between the presence of motor weaknesses of the ulnar nerve innervated muscles, sonographically thickening of the ulnar nerve, and motor conduction slowing of the ulnar nerve at the BE-AE segment. In addition, US provided information on nerve morphologic alterations regarding the echo texture and location of nerve enlargement.
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J Clin Neurophysiol · Feb 2012
Test-retest reliability of contact heat-evoked potentials from cervical dermatomes.
The purpose of this study was to investigate the test-retest reliability of contact heat-evoked potentials (CHEPs) in neurologically healthy subjects from cervical dermatomes (C4-C8). Seventeen individuals underwent test-retest examination of cervical CHEPs. Peak latencies and peak-to-peak amplitude of N2-P2 and ratings of perceived intensity were analyzed using test-retest reliability statistics (intraclass correlation coefficients [ICCs] and Bland-Altman confidence parameters). ⋯ Superior peak-to-peak amplitude test-retest reliability was found for CHEPs. In conclusion, the test-retest reliability of dSSEP and CHEP parameters supports the fact that these outcomes can be used to objectively track changes in spinal conduction in the dorsal column and spinothalamic tract, respectively. The reliable acquisition of CHEPs may depend on the intensity of the sensation reported by the subject for a given area of skin stimulated.