A Systematic Review of Seizure Onset Pattern in SEEG and a Proposal for Morphological Classification

Abstract

Abstract Background: Seizure onset pattern (SOP) represents an alteration of electroencephalography (EEG) morphology at the beginning of seizure activity in epilepsy. With stereotactic electroencephalography (SEEG), a method for intracranial EEG evaluation, many morphological SOP classifications have been reported without established consensus. These inconsistent classifications with ambiguous terminology present difficulties to communication among epileptologists. Methods: We systematically reviewed SOP in SEEG by searching the PubMed database. Reported morphological classifications and the ambiguous terminology used were collected. After thoroughly reviewing all reports, we reconsidered the definitions of these terms and explored a more consistent and simpler morphological SOP classification. Results: Of the 458 studies initially found,8 studies were finally included after screening and excluding irrelevant studies. We reconsidered EEG onset, period for determining type of SOP, core electrode and other terms in SEEG. We proposed a morphological SOP classification comprising four major types with three special subtypes. Conclusions: A systematic review of SOP in SEEG was performed. Our classification may be suitable for describing SOP morphology.