A clinical spectrum of the myoclonic manifestations associated with typical absences in childhood absence epilepsy. A video-polygraphic study.

We investigated the electroclinical features of 12 patients with childhood absence epilepsy (CAE), presenting with typical absence seizures associated with myoclonic manifestations of the face or neck. All patients underwent repeated and prolonged split-screen video-polygraphic EEG recordings. The polygraphic recordings and clinical correlations of the absence seizures were analysed. All patients presented with multi-quotidian, typical absence seizures. During the absences, the patients could show mild, rhythmic, myoclonic jerks involving facial areas (eyebrows, nostrils, perioral region, chin) or neck muscles (sternocleidomastoideus), with the same frequency as the spike-wave complexes. Polygraphic tracings demonstrated that the myoclonias were correlated to the spike component. Clinically, all patients showed a benign course, with complete seizure control under antiepileptic treatment. In the follow-up, 7 patients withdrew from treatment without relapse. We conclude that all our patients showed an electroclinical picture consistent with CAE. The occurrence of myoclonic manifestations of the face or neck associated with the absences did not influence the benign course of their disease. The electroclinical features observed in our group of patients differentiates our cases both from epilepsy with myoclonic absences and from absences with perioral myoclonia (with Video).