A typical absence seizure is a generalized seizure with abrupt onset and offset of altered awareness which can vary in severity (see specific syndromes). Memory for events during the seizures is usually impaired although there may be some retained awareness particularly for adolescents. Clonic movements of eyelids, head, eyebrows, chin, perioral or other facial parts may occur, most typically at 3Hz. Myoclonus of limbs can rarely occur. Oral and manual automatisms are common and there may be perseveration of behaviors occurring prior to seizure onset. Absence seizures were previously known as 'petit mal' seizures. Absence status epilepticus can occur.
CAUTION Individual absence seizure longer than 45 seconds or with a post-ictal phase consider focal seizure.
CAUTION Onset of absence seizures < 4 years consider glucose transporter disorders.