Risk Factors for Late Posttraumatic Seizures after Moderate to Severe Traumatic Brain Injury

Past Studies

Past Studies state that individuals can experience a seizure as a medical consequence of traumatic brain injury. A seizure occurs when there is a temporary electrical imbalance in the brain. A person experiencing a seizure can experience uncontrollable body movements, sensations, and awareness. “Early posttraumatic seizures” occur during the first week of a traumatic brain injury and “late posttraumatic seizures” occur after the first week.. An early posttraumatic seizure is associated with an increased risk for late posttraumatic seizures. A late posttraumatic seizure is associated with even a greater risk of having another one. Information is lacking about which risk factors are the most important for estimating the likelihood of late posttraumatic seizures for persons with moderate or severe traumatic brain injury.

This Study

This Study examined the medical records of 647 individuals with moderate and severe brain injuries for 24 months following their injuries. The researchers examined the participant’s Computed Tomography Scans (CT or CAT Scans), presence of early posttraumatic seizures, and initial Glasgow Coma Scale scores for any links or associations. CT Scans are pictures taken of the brain to detect bleeding, blood clots, swelling, and compression in the brain. The Glasgow Coma Scale is used to determine the severity of a brain injury. It is often used at the emergency scene or emergency room and evaluates a number of factors including eye and verbal responses and a person’s ability to move when instructed to do so

The researchers found that 66 individuals experienced a late posttraumatic seizure within two years from their injuries. For these individuals, it appears that the amount of direct brain tissue damage was the biggest factor linked with the occurrence of late posttraumatic seizures. Such brain tissue damage can occur from certain types of traumatic brain injuries that directly damage brain tissue and may be detected on initial CT scans. Brain tissue damage can occur when the brain bleeds, when bleeding happens in the tissues that cover the brain, or when the brain is directly injured by an object that penetrates the skull, such as a bullet. Individuals who had pieces of metal and bone lodged in their brains appeared to have an even higher risk of developing late posttraumatic seizures. Bleeding in multiple sites in the brain, particularly on both sides and severe enough to require surgical removal were also highly associated with late seizures. Invididuals who experienced bleeding in only one area or only in the linings around the brain were not at significantly greater risk for late seizures .Those with seizures during the first week post injurywere only at moderately increased risk for recurrent seizures. Initial injury severity alone, as measured by the Glasgow Coma Scale, did not appear to be associated with late posttraumatic seizures.

Who May Be Affected By These Findings

Persons with brain injuries and their friends and families, caregivers, healthcare providers, and researchers

Caveats

The results of this study may be limited in that 167 of the individuals did not participate for the full length of the study and 8% of the participants remained on anti-seizure medications for more than one month after the study began.

Bottom Line

Overall it appears that the amount of direct brain tissue damage is the biggest factor linked with the occurrence of late posttraumatic seizures. Certain CT Scan results, types of traumatic brain injuries especially those with foreign body penetration and multiple contusions, types and numbers of brain surgeries, and an early posttraumatic seizure appear to also be factors associated with a higher risk for late posttraumatic seizures. Future research is needed to further clarify the impact of posttraumatic seizures on the lives of individuals with TBI.

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