Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Jun 2015
ReviewConundrums of high-frequency oscillations (80-800 Hz) in the epileptic brain.
Pathological high-frequency oscillations (HFOs) (80-800 Hz) are considered biomarkers of epileptogenic tissue, but the underlying complex neuronal events are not well understood. Here, we identify and discuss several outstanding issues or conundrums in regards to the recording, analysis, and interpretation of HFOs in the epileptic brain to critically highlight what is known and what is not about these enigmatic events. ⋯ We provide a list of recommendations that could help to obtain comparable HFO signals in clinical and basic epilepsy research. Adopting basic standards will facilitate data sharing and interpretation that collectively will aid in understanding the role of HFOs in health and disease for translational purpose.
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J Clin Neurophysiol · Apr 2015
Baseline EEG pattern on continuous ICU EEG monitoring and incidence of seizures.
To identify the probability of detecting nonconvulsive seizures based on the initial pattern seen in the first 30 minutes of continuous EEG (cEEG) monitoring. ⋯ Patients with only generalized slowing seen on the baseline EEG recording are unlikely to develop seizures on subsequent cEEG monitoring. Depending on the clinical circumstance, the standard duration of cEEG recording (24-48 hours) may be unnecessary in patients with generalized slowing as their only cEEG abnormality.
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J Clin Neurophysiol · Apr 2015
Practice GuidelineConsensus statement on continuous EEG in critically ill adults and children, part II: personnel, technical specifications, and clinical practice.
Critical Care Continuous EEG (CCEEG) is a common procedure to monitor brain function in patients with altered mental status in intensive care units. There is significant variability in patient populations undergoing CCEEG and in technical specifications for CCEEG performance. ⋯ Recommended qualifications for CCEEG personnel and CCEEG technical specifications will facilitate standardization of this emerging technology.
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J Clin Neurophysiol · Apr 2015
Practice GuidelineConsensus statement on continuous EEG in critically ill adults and children, part I: indications.
Critical Care Continuous EEG (CCEEG) is a common procedure to monitor brain function in patients with altered mental status in intensive care units. There is significant variability in patient populations undergoing CCEEG and in technical specifications for CCEEG performance. ⋯ CCEEG has an important role in detection of secondary injuries such as seizures and ischemia in critically ill adults and children with altered mental status.
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J Clin Neurophysiol · Apr 2015
Case ReportsSevere hemispatial neglect as a manifestation of seizures and nonconvulsive status epilepticus: utility of prolonged EEG monitoring.
Seizures and status epilepticus causing hemispatial neglect syndromes are seldom diagnosed, in part because, without motor signs, EEGs are not performed. Also, nonconvulsive seizures are often intermittent and missed on a single EEG. Two patients had severe neglect syndromes thought due to strokes. Correct diagnosis of epileptic seizures required longer-term EEG monitoring. ⋯ Infrequently, the sudden onset of new hemispatial neglect can be caused by nonconvulsive seizures and nonconvulsive status epilepticus, even when there is no weakness and no clear clinical seizure activity. Nonconvulsive status epilepticus can cause primarily perceptual and cognitive syndromes. The correlation between the clinical deficits and seizure activity on the EEG, however, is imprecise. A single EEG may miss seizure activity, and repeated or prolonged EEG recording may be necessary to make the diagnosis.