LGI1-negative faciobrachial dystonic-like seizures originating from the insula

We expand the differential diagnosis of LGI1-positive faciobrachial dystonic seizures (FBDS) by presenting a 67-year-old woman affected by seizures of similar semiology who was found to have insular epilepsy. We report the distinct characteristics of insular faciobrachial dystonic-like seizures that would help clinicians to differentiate them from typical LGI1-positive FBDS, thus, guiding therapy while awaiting antibody results. LGI1-negative faciobrachial dystonic-like seizures should be considered when the seizure semiology includes unilateral and prolonged dystonia without loss of awareness, there is an ictal EEG correlate, MRI is suggestive of insular lesion, and when there is neither clearly associated memory impairment nor hyponatremia.