Your trustworthy assistant for HD-EEG diagnostics

& source localization during preoperative evaluation


Preoperative High Density (HD) EEG analysis in epilepsy patients is a time-consuming and labor-intensive process. Despite the fact that several studies prove the high value of HD-EEG recordings for precize source localization*, many epilepsy centres are struggling to analyze the data. This is mainly because current software solutions are not working efficiently.

Did you recently buy a HD-EEG system and are you not able to analyze the data to its fullest? Epilog PreOp HD offers you the perfect solution, so you can focus on the interpretation of the data without having software issues or delays in the analysis of the data.

*Brodbeck, Verena, Margitta Seeck et al. “Electroencephalographic source imaging: a prospective study of 152 operated epileptic patients.” Brain 134.10 (2011): 2887-2897.

Automated spike detection

Spikes are identified in the EEG recordings of your patients using FDA-approved / CE-marked algorithms if the recording is > 3 hours. For shorter recordings we recommend to manually mark the spikes in the recording.

3D patient-specific source localization

Six-layered head models are constructed from the MR image of your patient to localize the epileptic activity in the brain. Up to 256 electrodes are used to accurately estimate the location of the source in the brain.

Concise online report and 3D viewer

The results are concisely summarized in a report with clear visuals and 3D viewer for optimal epilepsy diagnosis and treatment.

Epilog PreOp HD automates the analysis of preoperative HD-EEG data and provides the results in a concise report with clear 3D visuals for optimal epilepsy diagnosis and treatment. The online Epilog platform can be accessed from anywhere in the world at any time. There are no hardware demands, Epilog PreOp HD is compatible with EGI, Brain Products, ANT and others. Because of the simple, user-friendly interface HD-EEG analysis is more efficient than ever before.

  • Saving time and resources
  • State-of-the-art source localization
  • Compatible with EGI, Brain Products, ANT and others
  • Consistent and objective reporting


Epilog is your partner supporting you with training, clear interpretation guidelines and HD-EEG cases that will improve your EEG analysis in clinical practice.

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Epilog PreOp HD used in clinical practice

Ghent University Hospital

At Ghent University Hospital patients go through an extensive work-up before the possibility of epilepsy surgery is discussed. All patients have long-term video-EEG-monitoring (usually 7 days), 3T MRI, FDG-PET and neuropsychological testing.

Geneva University Hospital

At the University Hospital of Geneva, the presurgical evaluation of refractory epilepsy patients contains a battery of clinical tests: structural MRI, video-EEG monitoring, interictal PET, ictal SPECT, neuropsychological examination, patient history and high-density EEG.