Abstract
We report a case of 29-year old woman with profound mental retardation. Since her early childhood, she has suffered from tonic seizure several times a month, tonic-clonic seizure once a year and contraction of the tongue and the extremities for an hour every day. Whether the contraction was epileptic seizure or involuntary movement has remained unclear. On admission day she exhibited the contraction. On EEG a few seconds of diffuse 2-3Hz spike and slow wave complexes and diffuse sharp wave-like rhythmic activity appeared alternately. The contraction was myoclonic status epilepticus. Diazepam infusion was not effective but the following phenobarbital infusion stopped the status. She also had atypical absence seizure, frequent smile and so on. Deletion of chromosome 15q11-13 was identified and she was diagnosed with Angelman syndrome. Patients with Angelman syndrome often present with myoclonic seizure and atypical absence seizure, which occasionally turn into status epilepticus. Angelman syndrome should be included into a differential diagnosis if a patient exhibits these seizures and mental retardation. Additionally, phenobarbital might be effective in myoclonic epilepsy of Angelman syndrome.
