High-frequency oscillations (HFO; gamma: 40-100 Hz, ripples: 100-200 Hz, and fast ripples: 250-500 Hz) have been widely studied in health and disease. These phenomena may serve as biomarkers for epileptic brain; however, a means of differentiating between pathological and normal physiological HFO is essential. We categorized task-induced physiological HFO during periods of HFO induced by a visual or motor task by measuring frequency, duration, and spectral amplitude of each event in single trial time-frequency spectra and compared them to pathological HFO similarly measured. Pathological HFO had higher mean spectral amplitude, longer mean duration, and lower mean frequency than physiological-induced HFO. In individual patients, support vector machine analysis correctly classified pathological HFO with sensitivities ranging from 70-98% and specificities >90% in all but one patient. In this patient, infrequent high-amplitude HFO were observed in the motor cortex just before movement onset in the motor task. This finding raises the possibility that in epileptic brain physiological-induced gamma can assume higher spectral amplitudes similar to those seen in pathologic HFO. This method if automated and validated could provide a step towards differentiating physiological HFO from pathological HFO and improving localization of epileptogenic brain.
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http://dx.doi.org/10.1152/jn.00341.2013 | DOI Listing |
Front Netw Physiol
November 2024
Yale Comprehensive Epilepsy Center, Department of Neurology, Yale School of Medicine, New Haven, CT, United States.
To date, there is no neurophysiologic or neuroimaging biomarker that can accurately delineate the epileptogenic network. High-frequency oscillations (HFO) have been proposed as biomarkers for epileptogenesis and the epileptogenic network. The pathological HFO have been associated with areas of seizure onset and epileptogenic tissue.
View Article and Find Full Text PDFClin Cancer Res
December 2024
Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts.
J Clin Neurophysiol
October 2024
Bioengineering, Neurosurgery, Electrical Engineering, Stanford University, Stanford, CA; and.
Purpose: Ictal high-frequency oscillations (HFOs) are a reliable indicator of a seizure onset zone for intracranial EEG recordings. Interictal HFOs often are also observed and may be a useful biomarker to supplement ictal data, but distinguishing pathologic from physiologic HFOs continues to be a challenging task. We present a method of classifying HFOs based on morphologic contrast to the background.
View Article and Find Full Text PDFmedRxiv
November 2024
Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, CA, USA.
Chest
November 2024
SIAARTI Systematic Review Group, Rome, Italy; Department of Anesthesia, Analgesia, Intensive Care and Emergency, University Hospital Policlinico Paolo Giaccone, Palermo, Italy; Department of Precision Medicine in Medical, Surgical and Critical Care. University of Palermo, Palermo, Italy. Electronic address:
Background: Reintubation is associated with higher risk of mortality. There is no clear evidence on the best spontaneous breathing trial (SBT) method to reduce the risk of reintubation.
Research Question: Are different methods of conducting SBTs in critically ill patients associated with different risk of reintubation compared with T-tube?
Study Design And Methods: We conducted a systematic review and Bayesian network meta-analysis of randomized controlled trials investigating the effects of different SBT methods on reintubation.
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