Seizures originating from the middle and posterior cingulate: A systematic review

We performed a systematic review of the ictal semiology associated with middle and posterior cingulate seizures in focal epilepsy. Our aim was to summarize the current state-of-the-art anatomo-clinical correlations and provide guidance for interpreting ictal semiology within the context of pre-surgical evaluation.

We conducted a literature review following PRISMA guidelines using predefined search terms. Eligible studies included original clinical cohort studies and case series with three or more patients who underwent surgical treatment and pre-surgical evaluation for middle cingulate cortex (MCC) and posterior cingulate cortex (PCC) epilepsies, utilizing Video-EEG and/or invasive stereo EEG (SEEG). Only cases with high confidence in the seizure onset zone (SOZ), either through histology or invasive EEG, were included in this meta-analysis.

Five clinical studies involving 57 patients with MCC and PCC epilepsies met the inclusion criteria. Observed seizure semiology for both groups included tonic and dystonic movements, vocalizations, automatisms, and autonomic symptoms. The studies also identified distinct patterns of semiology between MCC and PCC: MCC epilepsies were associated with hyperkinetic and tonic seizures, often accompanied by emotional symptoms, forming a continuum with anterior cingulate epilepsies. In contrast, PCC epilepsies exhibited more discrete motor symptoms and frequently presented with auras and automatisms reminiscent of mesial temporal lobe epilepsies. Studies utilizing SEEG analyses revealed distinct ictal spread patterns when comparing MCC and PCC epilepsies, suggesting that semiology in MCC and PCC epilepsies is defined more by ictal spread than by the seizure onset zone itself.

This study identified semiologic patterns commonly associated with MCC and PCC epilepsies, which help distinguish these epilepsy subgroups from each other and from other focal epilepsies. In cases of epilepsy presenting with temporomesial semiology but lacking a corresponding lesion on cerebral imaging, a PCC epilepsy should be considered.