| A common type of self-limited focal epilepsy syndrome, which begins typically between four and ten years (peak is seven years; range three to twelve years). Seizures are focal, infrequent (most children have fewer than ten in lifetime), brief (typically less than two to three minutes) and occur mostly in sleep (eighty to ninety percent of children). Individuals may have frequent seizures over a few days or weeks and then several months before subsequent seizure. Focal seizures with characteristic frontoparietal opercular features and/or nocturnal bilateral tonic-clonic seizures are mandatory for diagnosis. Characteristic semiology includes somatosensory symptoms (unilateral numbness or paresthesia of the tongue, lips, gums and inner cheek), orofacial motor signs (unilateral tonic or clonic contractions), speech arrest (dysarthria or anarthria) with preserved understanding, and sialorrhea. Seizures may evolve rapidly to tonic-clonic activity of the ipsilateral upper limb, to an ipsilateral hemiclonic seizure, or to a focal to bilateral tonic-clonic seizure. Todd paresis may occur postictally. Seizures occurring during sleep are seen within one hour of falling asleep or one to two hours prior to awakening. Development and cognition are typically normal. Neurological examination is normal. The electroencephalogram (EEG) background activity is normal. EEG must show centrotemporal biphasic epileptiform discharges which are characteristically high-amplitude complexes (less than 200 microvolts, peak to trough) that activate in drowsiness and sleep. MRI is normal or has nonspecific findings. |
