Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Oct 1993
ReviewContinuous EEG and evoked potential monitoring in the neuroscience intensive care unit.
As with other methods long used in intensive care units (ICU) and operating rooms (OR), the goal of neuroscience ICU continuous EEG (NICU-CEEG) and evoked potential (NICU-EP) monitoring is to extend our powers of observation to detect abnormalities at a reversible stage. EEG is an appropriate monitoring tool because it is linked to cerebral metabolism, is sensitive to ischemia and hypoxemia, correlates with cerebral topography, detects neuronal dysfunction at a reversible stage, and is the best method for detecting seizure activity. When applied systematically, it can impact medical decision-making in 81% of monitored patients. ⋯ Real-time digitized EEG in particular has been a major advance. Within limits, somatosensory evoked potential monitoring (ICU-SEP) is useful in the prognosis of coma, but it is less helpful in monitoring focal cerebral ischemia. Brainstem auditory evoked potential monitoring has a relatively restricted role in the NICU but is helpful in distinguishing structural from nonstructural causes of coma and can supplement ICU-SEP in predicting outcome.
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J Clin Neurophysiol · Oct 1993
Alfentanil-induced epileptiform activity in patients with partial epilepsy.
We performed a retrospective study investigating the effect of alfentanil hydrochloride on electrocorticography (ECoG) in 23 patients with intractable nonlesional partial epilepsy undergoing anterior temporal lobectomies at this institution. Alfentanil is a short-acting, parenteral, opioid analgesic with a rapid onset of action. Opioid drugs have the potential to induce hippocampal electrographic seizures. ⋯ One patient had an alfentanil-induced mesial temporal lobe electrographic seizure. Alfentanil did not have a significant effect on spike activity in the suprasylvian region (p = 0.500). Further studies will be necessary to determine the specificity of alfentanil activation in patients with partial seizures of temporal lobe origin.
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J Clin Neurophysiol · Oct 1993
Equivalent electrical source analysis of pain-related somatosensory evoked potentials elicited by a CO2 laser.
The purpose of this study was to localize possible neural sources of pain-related cortical evoked potentials. A brain electrical source analysis was performed on late somatosensory evoked potential data (500-ms window was analyzed) elicited by short heat pulses produced by a CO2 laser. These stimuli activate pain and temperature pathways. ⋯ This dipole was located too frontally to be thalamic, but it corresponded well to the location of the anterior cingulate gyrus. The model also yielded good fits for right-hand and left-foot stimulation data and, in addition, another set of left-hand data obtained with different electrode spacing in a different group of subjects (residual variances from 2.8% to 3.3%). The model explaining data sets from different body part stimulations varied very little, except with respect to the location of the dipole representing the activity of the primary somatosensory area.(ABSTRACT TRUNCATED AT 250 WORDS)