Aeromedical decision making and seizure risk after traumatic brain injury: longitudinal outcome

Traumatic brain injury (TBI) is common in young adults and therefore of significant concern to an aircrew population. This paper reports the occurrences of seizures in U.S. Air Force (USAF) aircrew following receipt of an aeromedical waiver for TBI.

Using both an aeromedical waiver tracking system database and medical records, we identified surrogate seizure markers such as all episodes of subsequent TBI, seizure, loss of consciousness, or prescription of anticonvulsant medications from the time of initial TBI until the last medical visit or entry recorded in either the database or medical records for our study population.

The seizure rate for aircrew who met USAF waiver criteria was 24.53/100,000 person-years. One pilot experienced a major motor seizure 14.9 yr following a severe TBI for an incidence of 308.64/100,000 person-years.

The USAF waiver process following TBI was sufficiently effective in removing aircrew with elevated risk for seizure following TBI. While our rates of post-traumatic seizure appear to be lower than previously published civilian population rates, direct comparison cannot be made secondary to differences in study design and selection criteria. Further areas of study could involve a more detailed analysis of aircrew neurocognitive status following TBI for subtle changes, crosschecking USAF Safety Center data for changes in accident rates among post-TBI aircrew, and analysis of lost aircrew flying time as a result of TBI and the degree of burden that loss places on the flying mission.

Application of these stringent criteria is sufficient to fulfill aeromedical safety standards, but costs remain undetermined.