High-Density EEG in Current Clinical Practice and Opportunities for the Future

J Clin Neurophysiol. 2021 Mar 1;38(2):112-123. doi: 10.1097/WNP.0000000000000807.

Abstract

High-density EEG (HD-EEG) recordings use a higher spatial sampling of scalp electrodes than a standard 10-20 low-density EEG montage. Although several studies have demonstrated improved localization of the epileptogenic cortex using HD-EEG, widespread implementation is impeded by cost, setup and interpretation time, and lack of specific or sufficient procedural billing codes. Despite these barriers, HD-EEG has been in use at several institutions for years. These centers have noted utility in a variety of clinical scenarios where increased spatial resolution from HD-EEG has been required, justifying the extra time and cost. We share select scenarios from several centers, using different recording techniques and software, where HD-EEG provided information above and beyond the standard low-density EEG. We include seven cases where HD-EEG contributed directly to current clinical care of epilepsy patients and highlight two novel techniques which suggest potential opportunities to improve future clinical care. Cases illustrate how HD-EEG allows clinicians to: case 1-lateralize falsely generalized interictal epileptiform discharges; case 2-improve localization of falsely generalized epileptic spasms; cases 3 and 4-improve localization of interictal epileptiform discharges in anatomic regions below the circumferential limit of standard low-density EEG coverage; case 5-improve noninvasive localization of the seizure onset zone in lesional epilepsy; cases 6 and 7-improve localization of the seizure onset zone to guide invasive investigation near eloquent cortex; case 8-identify epileptic fast oscillations; and case 9-map language cortex. Together, these nine cases illustrate that using both visual analysis and advanced techniques, HD-EEG can play an important role in clinical management.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Brain Mapping / methods*
  • Brain Mapping / trends
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / physiopathology
  • Child
  • Electrodes / trends
  • Electroencephalography / methods*
  • Electroencephalography / trends
  • Epilepsy / diagnostic imaging*
  • Epilepsy / physiopathology*
  • Female
  • Forecasting
  • Humans
  • Infant
  • Male
  • Middle Aged
  • Scalp / diagnostic imaging
  • Scalp / physiopathology
  • Seizures / diagnostic imaging
  • Seizures / physiopathology
  • Young Adult