Absence seizures with myoclonic seizures as an early manifestation of dentato-rubro-pallido-luysian atrophy (DRPLA): a follow-up clinical course of twelve years.

Typical absence seizures and isolated myoclonic seizures are both classified as age-related generalized seizures and are considered to be benign neurological manifestations. Concomitance of the two types of seizure is considered benign if it does not accompany other types of seizures or other neurological problems. We followed up a ten-year-old girl with isolated absence and myoclonic seizures whose family history of mental and neurological signs was initially not disclosed. After several years, the family history of neurological and mental problems was finally disclosed, and the diagnosis of dentato-rubro-pallido-luysian atrophy (DRPLA) was confirmed. The patient's clinical course was slowly progressive, and by age 21 she was in a nearly vegetative state. We would like to alert clinicians to consider DRPLA when diagnosing patients with absence and/or myoclonic seizures, even when they present the clinical features of benign epilepsies in the early stage.