Post-traumatic seizure

Post-traumatic seizures (PTS) are seizures that result from traumatic brain injury (TBI), brain damage caused by physical trauma. PTS may be a risk factor for post-traumatic epilepsy (PTE), but a person having a seizure or seizures due to traumatic brain injury does not necessarily have PTE, which is a form of epilepsy, a chronic condition in which seizures occur repeatedly. However, "PTS" and "PTE" may be used interchangeably in medical literature. Seizures are usually an indication of a more severe TBI. Seizures that occur shortly after a person sustains a brain injury may further damage the already vulnerable brain. They may reduce the amount of oxygen available to the brain, cause excitatory neurotransmitters to be released in excess, increase the brain's metabolic need, and raise the pressure within the intracranial space, further contributing to damage. Thus, people who sustain severe head trauma are given anticonvulsant medications as a precaution against seizures. Around 5–7% of people hospitalized with TBI have at least one seizure. PTS are more likely to occur in more severe injuries, and certain types of injuries increase the risk further. The risk that a person will develop PTS becomes progressively lower as time passes after the injury. However, TBI survivors may still be at risk over 15 years after the injury. Children and older adults are at a higher risk for PTS. In the mid-1970s, PTS was first classified by Bryan Jennett into early and late seizures, those occurring within the first week of injury and those occurring after a week, respectively. Though the seven-day cutoff for early seizures is used widely, it is arbitrary; seizures occurring after the first week but within the first month of injury may share characteristics with early seizures. Some studies use a 30‐day cutoff for early seizures instead. Later it became accepted to further divide seizures into immediate PTS, seizures occurring within 24 hours of injury; early PTS, with seizures between a day and a week after trauma; and late PTS, seizures more than one week after trauma.