title: Interictal high-frequency oscillations in focal human epilepsy.
abstract: OBJECTIVE
  Localization of focal epileptic brain is critical for successful epilepsy surgery and focal brain stimulation. Despite significant progress, roughly half of all patients undergoing focal surgical resection, and most patients receiving focal electrical stimulation, are not seizure free. There is intense interest in high-frequency oscillations (HFOs) recorded with intracranial electroencephalography as potential biomarkers to improve epileptogenic brain localization, resective surgery, and focal electrical stimulation. The present review examines the evidence that HFOs are clinically useful biomarkers.
  
  
  RESULTS
  Performing the PubMed search 'High-Frequency Oscillations and Epilepsy' for 2013-2015 identifies 308 articles exploring HFO characteristics, physiological significance, and potential clinical applications.
  
  
  CONCLUSIONS
  There is strong evidence that HFOs are spatially associated with epileptic brain. There remain, however, significant challenges for clinical translation of HFOs as epileptogenic brain biomarkers: Differentiating true HFO from the high-frequency power changes associated with increased neuronal firing and bandpass filtering sharp transients. Distinguishing pathological HFO from normal physiological HFO. Classifying tissue under individual electrodes as normal or pathological. Sharing data and algorithms so research results can be reproduced across laboratories. Multicenter prospective trials to provide definitive evidence of clinical utility.
authors.affiliation: aMayo Systems Electrophysiology Laboratory, Department of NeurologybDepartment of Biomedical Engineering and Physiology, Mayo Clinic, Rochester, Minnesota, USAcInternational Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Cimbalnik
authors.forename: Michal T
authors.initials: MT
authors.lastname: Kucewicz
authors.forename: Greg
authors.initials: G
authors.lastname: Worrell
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D004558:Electric Stimulation / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans
chemical_list: D015415:Biomarkers