Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Feb 2007
Central processing of acute muscle pain in chronic low back pain patients: an EEG mapping study.
The presence of perceptual sensitization and related brain responses was examined in 14 chronic low back pain (CLBP) patients and 13 healthy controls comparable in age and sex. Multichannel EEG recordings and pain ratings were obtained during the presentation of 800 painful electrical intramuscular and intracutaneous stimuli each to the left m. erector spinae and the left m. extensor digitorum. Perception and pain thresholds were not significantly different between the two groups, though patients showed significantly more perceptual sensitization. ⋯ These results indicate enhanced perceptual sensitization and enhanced processing of the sensory-discriminative aspect of pain, as expressed in the N80 component, in CLBP patients. This may be one neurophysiologic basis of sensitization and the chronicity process. The lower P260 component in the patients may be explained in terms of tonic pain inhibiting phasic pain or may be related to the affective distress observed in this patient group.
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J Clin Neurophysiol · Aug 2006
ReviewValue and limitations of seizure semiology in localizing seizure onset.
Seizure semiology has been the foundation of clinical diagnosis of seizure disorders. This article discusses the value and the limitations of behavioral features of seizure episodes in localizing seizure onset. Studies have shown that some semiologic features of seizures are highly accurate in the hemispheric lateralization and lobar localization of seizures. ⋯ Many semiologic features of seizures of adults are often missing in seizures of children. Seizure semiology should be analyzed and integrated with EEG and neuroimaging data to localize the seizure focus. A sample of the recorded seizures should be shown to the patient's relatives or friends to verify that it is representative of habitual seizures.
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J Clin Neurophysiol · Aug 2005
Comparative StudyQEEG changes during carotid clamping in carotid endarterectomy: spectral edge frequency parameters and relative band power parameters.
Intraoperative monitoring is needed to identify accurately those patients in need of a shunt during carotid endarterectomy. EEG can be used for this purpose, but there is no consensus on the variables to use. Using a database consisting of 149 EEGs recorded from patients during carotid endarterectomy under isoflurane (n=61) or propofol (n=88) anesthesia and who did or did not receive a shunt, the authors investigated which of 16 derivations (common reference, Cz) and 12 parameters (relative and absolute powers and spectral edge frequencies [SEFs]) singly or in combination could best distinguish between the shunt and the nonshunt groups for the two anesthesia regimens. ⋯ Discriminant analysis, in which additional derivation/parameter combinations were added, increased the discriminative power of the DeltalogP computation but not of the C or C-B computations. For isoflurane anesthesia, SEF 90% was the best single parameter for distinguishing between patients who did and did not need a shunt and the four best derivations were F3-Cz, P4-Cz, C4-Cz, and F7-Cz. For the propofol anesthesia, the relative power (C or C-B computations) of the delta band was the best and the four best derivations were F8-Cz, T4-Cz, C4-Cz, and F4-Cz.
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J Clin Neurophysiol · Jun 2005
Randomized Controlled Trial Comparative Study Clinical TrialDetermination of sensitive electrophysiologic parameters at follow-up of different steroid treatments of carpal tunnel syndrome.
Nonsurgical treatment for carpal tunnel syndrome (CTS) is frequently offered to those with mild to moderate symptoms. However, the most sensitive electrophysiological parameters at follow-up, and most effective type of different methods of steroid treatment for CTS, remain unknown. The aim of this study was to compare the efficacy of local corticosteroid injection, phonophoresis, and iontophoresis for the treatment of CTS, and to evaluate the most sensitive electrophysiologic parameters at the follow-up visit. ⋯ The local steroid injection group showed a significant improvement in the mean nerve conduction parameters after the second and fourth months when compared with basal values, whereas no significant changes except the difference between the median and ulnar distal latency to the fourth digit (D4M-D4U), difference between sensory median distal latency to second digit and ulnar distal latency to the fifth digit (D2M-D5U), and median motor distal latency were observed in the iontophoresis and phonophoresis groups. At the end of follow-up period, the most sensitive parameters were D4M-D4U and D2M-D5U; the D4M-D4U was improved 60% in the injection group, 33% in iontophoresis group, and 39% in phonophoresis group, and the improvement of the D2M-D5U was 70%, 28%, and 28%, respectively, in the injection, iontophoresis, and phonophoresis groups. These findings show that steroid injection is superior to iontophoresis and phonophoresis in the treatment of CTS, and that the most sensitive neurophysiologic parameters in follow-up are D4M-D4U and D2M-D5U, being the objective measures of the outcome of CTS treatment.
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J Clin Neurophysiol · Apr 2005
ReviewMultimodal brain monitoring in the neurological intensive care unit: where does continuous EEG fit in?
Continuous EEG (cEEG) is a vital component of patient monitoring in the neurologic intensive care unit, allowing the intensivist to diagnose nonconvulsive seizure activity. Though still in its infancy, Fourier-transformed cEEG data are also increasingly being used in ICUs to monitor global cerebral activity and cortical function. In conjunction with other components of multimodality neurologic monitoring, including intracranial pressure, cerebral blood flow, brain tissue oxygen tension monitoring, transcranial Doppler, and microdialysis monitoring, cEEG provides unique data regarding the electrical activity of the brain. The main challenge for clinicians and researchers will be to understand how these different aspects of multimodality monitoring relate to each other, and how physiologic variables such as blood pressure, osmolality, and temperature can be manipulated to optimize cerebral function and tissue survival in the setting of acute injury.