Abstracts

Rationale: The frontal ictal semiology is organized along a rostrocaudal axis, with more limbic and integrative features rostrally, and more executive then elementary motor signs caudally. In frontal epilepsy the stereotyped movements are predominantly associated with seizures in which lateral prefrontal cortex is involved at onset, projecting to anterior cingulate cortex (ACC) and/or pre-SMA. Meanwhile the knowledge about the caudal ACC motor semiology remains sparse. Methods: We report peculiar movement semiology in three patients with caudal ACC epilepsy demonstrated by intracranial depth electrode exploration. Results: All patients had an early peculiar motor semiology with a repeated non-goal-directed movement pattern. These motor peculiar features were axial and proximal limb alternating rotation movements that may fit the stereotypies definition. Moreover they seem to follow an existing somatotopic organization that was recently described by fMRI studies. Conclusions: The ACC semiology follows the same rostrocaudal axis organization as the frontal ictal semiology more generally does. Early peculiar stereotypies may suggest the involvement of the caudal ACC within an existing somatotopic organization. Funding: No funding.