[A case of 18 q-syndrome associated with status epilepticus].

: A 15-year-old boy with 18 q-syndrome manifesting a status epilepticus is reported. He has been already diagnosed as epilepsy because of grand mal seizures at six months earlier, and abnormal EEG findings. Unilateral status epilepticus developed at 15 years of age, which were characterized by alternative repetition of horizontal nystagmus to the right and clonic convulsion of the right (mainly upper) extremities every several minutes. Ictal EEG showed continuous 2 Hz high voltage slow waves superimposed by spikes and polyspikes which transformed to localized, irregular spike discharges in the left occipital region at the end of the status. The chromosomal study revealed a partial deletion of the long arm of No. 18. He had severe mental retardation, and a typical karyotype for 18 q-syndrome with reduced prominence of the midface region, short stature and whorls on all finger tips. The immaturity of the brain probably relates to this kind of unilateral status epilepticus.