Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Dec 2015
ReviewACNS Critical Care EEG Terminology: Value, Limitations, and Perspectives.
The interpretation of the EEG in the critically ill remains a clinical challenge. Because continuous EEG monitoring plays an increasing role in patients' care, it is important that research efforts investigate the clinical significance of periodic and rhythmic discharges and of background abnormalities. ⋯ Studies using the terminology have already started to define the clinical and prognostic values of several known or newly described EEG patterns. Yet, as the field of critical care EEG evolves, improvements will be required to further enhance the clarity of the terminology and incorporate new findings from ongoing research.
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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 · Feb 2015
ReviewRespiratory pathophysiology with seizures and implications for sudden unexpected death in epilepsy.
There is increasing evidence that periictal respiratory disturbances are an important contributor to the pathophysiological changes leading to sudden unexpected death in epilepsy (SUDEP). In patients with SUDEP occurring in epilepsy monitoring units, respiratory disturbances occurred early in the postictal period and frequently preceded terminal bradycardia and asystole. Periictal hypoxemia and hypercapnia are observed in about one-third of patients undergoing video-EEG telemetry. ⋯ Serotonergic neurons modulate the excitability of the neuronal network generating the respiratory rhythm. Ictal and periictal impairment of serotonergic and glutaminergic neurons involved in the arousal system may also predispose to SUDEP by impeding the patient's ability to reposition the head and facilitate ventilation after a seizure. Periictal functional impairment of serotonergic neurons seems to be important in the pathophysiology of SUDEP and a potential target for pharmacotherapy aimed at SUDEP risk reduction.
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J Clin Neurophysiol · Apr 2014
ReviewComparative effectiveness analyses of intraoperative neurophysiological monitoring in spinal surgery.
Intraoperative neurophysiological monitoring for surgeries of the spine has been performed in clinical practice for several decades, but recent alterations in reimbursement schemes by third party payers have raised issues of the value of these procedures. Decision modeling using comparative effectiveness techniques holds the promise of evidence-based assessment of both cost and meaningful outcomes. In this article, we review the elements of comparative effectiveness analyses followed by a critical appraisal of the small but growing body of cost-effectiveness literature for intraoperative neurophysiological monitoring in spine.
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Intraoperative neurophysiologic monitoring endeavors to preserve the integrity of the nervous system at a time of potential risk. The examination of language function in the operative setting is a unique task that requires a detailed and systematic approach to be carried out efficiently and reliably in this dynamic environment. ⋯ This technique requires a coordinated effort to testing, which is reliant on preoperative assessment and structured approach to functional cortical mapping by the surgical, anesthetic, and neurophysiology teams. Despite the intricate nature of this modality of testing, the accurate identification of language areas facilitates neurosurgeries for tumor and focal epilepsy syndromes in the dominant cerebral hemisphere, which depend on maximal margins of resection for best outcomes.