Perioral myoclonia with absence seizures: a rare epileptic syndrome.

We present the clinical and video-EEG data on an epileptic boy whose absence seizures with marked perioral movements had started at the age of 1.5 years. From age 12 years, he experienced frequent episodes of typical absence status epilepticus (ASE) lasting 1-2 hours with marked perioral myoclonia and moderate confusion. Initial therapy with carbamazepine was substituted by valproate because of worsening of the absence seizures. At the age of 17, the patient was admitted to our clinic with his usual, but long lasting ASE attack, accompanied by 2 generalized tonic-clonic convulsions. ASE was confirmed with the EEG which showed continuous 3 Hz spike and wave paroxysms with occasional normal intervals of 1-5 seconds. IV injection of clonazepam improved the clinical and EEG findings immediately. Video- EEG examination performed after a few weeks demonstrated typical absence seizures with perioral myoclonia. Based on the characteristics of seizure semiology, other clinical data and EEG findings, the patient was diagnosed as having the syndrome of "perioral myoclonia with absence seizures" described by Panayiotopoulos.