Eyelid fluttering, typical EEG pattern, and impaired intellectual function: a homogeneous epileptic condition among the patients presenting with eyelid myoclonia.

PURPOSE: This retrospective study aims to review the electroclinical features of patients presenting with eyelid myoclonia (EM) with and without absences. METHODS: The Italian chapter of the International League Against Epilepsy (ILAE) has been conducting an electroclinical study of patients with EM. Among these, we searched for and selected the patients presenting with both impairment of intellectual functions and a peculiar ictal electroencephalography (EEG) pattern, that is, a discharge of fast generalized polyspikes/polyspikes and waves. RESULTS: We found 18 patients matching this electroclinical picture. All the patients were photosensitive. All of them had associated generalized, mostly nocturnal, tonic-clonic seizures. During the evolution, 13 patients presented episodes of EM status. Despite adequate antiepileptic treatment, the patients remained drug resistant for many years or throughout the evolution. The degree of impairment of intellectual functions varied from borderline level to moderate mental retardation. DISCUSSION: The patients we described herein can be considered a homogeneous group in the more heterogeneous group of patients presenting with EM. Further clinical and, more probably, genetic studies will clarify whether this condition could be considered a specific and homogeneous condition in the more heterogeneous group of patients presenting with EM.