Unusual features in eyelid myoclonia with absences: a patient with mild mental retardation and background slowing on electroencephalography.

"Eyelid myoclonia with and without absences" has been incorporated into the new ILAE diagnostic scheme as a type of epileptic seizure with etiologic, therapeutic, and prognostic implications. Eyelid myoclonia with absences (EMA) is characterized by eyelid myoclonia and absences provoked mainly by eye closure and photosensivity. EMA can be a part of idiopathic, symptomatic, or probably symptomatic epileptic syndromes. EMA is the defining seizure symptom that differentiates the idiopathic reflex epileptic syndrome Jeavons syndrome from eyelid myoclonia with absences. Jeavons syndrome is characterized by unique clinical and electroencephalographic features and often genetic clustering. EMA is easily diagnosed by clinical manifestations and properly conducted electroencephalography. However, it is often misdiagnosed as tics or other types of epileptic seizures and syndromes, particularly in patients with mental retardation, behavioral disturbances, and atypical electroencephalographic findings. We describe a 19-year-old woman with EMA who remained undiagnosed for many years. She was mildly mentally retarded and her electroencephalogram showed slow background activity, which are unusual findings in Jeavons syndrome.