Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Nov 2018
Short "Infraslow" Activity (SISA) With Burst Suppression in Acute Anoxic Encephalopathy: A Rare, Specific Ominous Sign With Acute Posthypoxic Myoclonus or Acute Symptomatic Seizures.
Slow wave with frequency <0.5 Hz are recorded in various situations such as normal sleep, epileptic seizures. However, its clinical significance has not been fully clarified. Although infra-slow activity was recently defined as activity between 0.01 and 0.1 Hz, we focus on the activity recorded with time constant of 2 seconds for practical usage. We defined short "infraslow" activity (SISA) less than 0.5 Hz recorded with time constant of 2 seconds and investigated the occurrence and clinical significance of SISA in acute anoxic encephalopathy. ⋯ Short infra-slow activity in acute anoxic encephalopathy could be associated with acute posthypoxic myoclonus and acute symptomatic seizures. Short infra-slow activity could be a practically feasible biomarker for myoclonus or seizures and poor prognosis in acute anoxic encephalopathy, if it occurs with burst suppression.
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J Clin Neurophysiol · Sep 2018
ReviewDoes Continuous Video-EEG in Patients With Altered Consciousness Improve Patient Outcome? Current Evidence and Randomized Controlled Trial Design.
Continuous video-EEG is recommended for patients with altered consciousness; as compared to routine EEG (lasting <30 minutes), it improves seizure detection, but is time- and resource-consuming. Although North American centers increasingly implement continuous video-EEG, most other (including European) hospitals have insufficient resources. Only one study suggested that continuous video-EEG could improve outcome in adults, and recent assessments challenge this view. ⋯ This study should help clarifying whether cEEG has a significant impact on outcome and define its cost effectiveness. If the trial will result positive, it will encourage broader implementation of cEEG with consecutive substantial impact on health care and resource allocations. If not, it may offer a rationale to design a larger trial, and - at least for smaller centers - to avoid widespread implementation of cEEG, rationalizing personnel and device costs.
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J Clin Neurophysiol · Sep 2018
Comparative StudyComparison of Transcranial Motor Evoked Potential Amplitude Responses Between Intramuscular and Subcutaneous Needles in Proximal Thigh Muscle.
Successful intraoperative neurophysiological monitoring is predicated on the presence of adequate baseline-evoked potentials. We have observed that transcranial motor evoked potentials (TcMEPs) yield more robust responses in the distal muscles compared with proximal muscles. One possible explanation is the distance from the needle to the muscle generator. In this study, we investigate whether TcMEP amplitudes from the rectus femoris muscle are affected by changes in needle length. ⋯ Higher TcMEP amplitude responses are seen with longer needles compared with shorter needles placed in the same rectus femoris muscle. Transcranial motor evoked potential baselines may be optimized using longer needles. Skinfold thickness can be a good marker to determine appropriate needle size.
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J Clin Neurophysiol · Sep 2018
Case ReportsInsights Into the Therapeutic Effect of Responsive Neurostimulation Assessed With Scalp EEG Recording: A Case Report.
The responsive neurostimulation system (RNS) is the first closed-loop neurostimulator approved as an adjunctive treatment for adults with medically refractory focal epilepsy from no more than two seizure foci. In addition to its therapeutic effect, it provides chronic intracranial EEG recordings, with limited storage capacity. Long-term monitoring with scalp EEG recordings can provide additional information regarding seizure patterns, the efficacy of RNS stimulation in aborting individual seizures, and the net effect of RNS on seizure control. ⋯ Responsive neurostimulation system stimulation did not abort any of the seizures recorded on the scalp EEG. However, the frequency of seizures doubled after RNS stimulation was discontinued and returned to baseline once it was turned back on. This observation supports the neuromodulation effect of RNS.
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J Clin Neurophysiol · Jul 2018
Continuous Electroencephalography in the Critically Ill: Clinical and Continuous Electroencephalography Markers for Targeted Monitoring.
Electrographic seizures detected by continuous electroencephalography (CEEG) in critically ill patients with altered mental status is becoming increasingly recognized. Data guiding the appropriate selection of patients to be monitored on CEEG are lacking. The aims of this article were to study the incidence of seizures in the critical care setting and to evaluate for clinical predictors to improve the efficiency of CEEG monitoring. ⋯ Continuous electroencephalography monitoring in the critical care setting demonstrates a linear increase in seizure incidence with declining mental status. Recognizing clinical conditions and electroencephalography markings may help in the appropriate selection of critically ill patients for CEEG monitoring.