| A type of self-limited focal epilepsy with onset of focal seizures in infancy (peak age six months; range three to twenty months). Focal seizure semiology includes behavioral arrest, cyanosis, staring with impaired awareness, automatisms, head/eye version and clonic movements. Individual focal clonic seizures originating from either hemisphere may occur in the same child and can progress to become focal to bilateral tonic-clonic seizures. Seizures are usually brief (less than three minutes). Seizures are often frequent (five to ten per day over one to three days) and may be difficult to control at onset. Development and cognition are typically normal. Neurological examination is normal. The electroencephalogram (EEG) background activity is normal but can have focal background slowing postictally. The interictal EEG is normal but can have midline spikes during slow sleep. MRI is normal or has nonspecific findings. Pathogenic variants in the PRRT2 gene are most commonly identified. Pathogenic variants in SCN2A, KCNQ2, KCNQ3 and SCN8A genes are causative in some individuals. |
