Two percent of patients with traumatic brain injury (TBI) experience early seizures, defined as occurring while the patient is still suffering from the direct effects of the head injury, usually within the first 24 hours of injury although up to 2 weeks later in those with severe head trauma. The decision to initiate or withhold antiepileptic drug (AED) therapy has far-reaching implications for rehabilitation of the traumatic brain-injured patient. Episodes of abnormal behavior occur commonly after severe head injuries and present a diagnostic challenge for the treating physician. TBI patients possess a lower tolerance to the central nervous system (CNS) side effects of psychotropic drugs and other medications. Seizures should be considered when episodes of discrete and stereotypic behaviors occur with or without altered or lost consciousness. Risk factors for posttraumatic epilepsy have been examined in several population studies. Video electroencephalographic monitoring involves continuous recording of electroencephalographic, electrocardiographic, and other electrophysiologic data with simultaneous video recording of behavior.