Post-Traumatic Epilepsy: A Longitudinal, Population-Based Medical Record Review Analysis of Incidence, Risk, and Prediction

Both seizures and traumatic brain injury (TBI) increase risk for developing other medical conditions and can lead to social disadvantages and bias. When seizures are caused by TBI, a condition called post-traumatic epilepsy or PTE, these risks are even greater. This is an enormous challenge for individuals in military and civilian life and their families. The changes in the brain caused by trauma that lead to someone having seizures are poorly understood, and there are currently no medical treatments that prevent seizures after TBI. Knowing how often individuals actually develop seizures after TBI (or PTE) is very important, because it can help doctors counsel individuals who have a TBI how likely it is for them to develop PTE. The best and most accurate way to find out what risk there is for developing PTE after TBI is to identify a large group of individuals within a defined population (for instance, in an entire county) who we know had a TBI by looking in their medical record with their consent. That allows us to collect a sample of individuals that represents the population of that county (all ages and both sexes), determine how severe the TBI was (mild, moderate, or severe), and record details of their lives and medical conditions. When a group of individuals with TBI that represents the population is identified, each of those individuals can be matched to another member of the population who are like the individual with TBI (same age and sex), but who did not have a TBI as determined by reviewing their medical record with their consent. By following both groups over time, we can find out how frequently individuals with TBI developed seizures and compare that to the group matched to them without TBI. That is the most accurate way to determine the incidence of PTE in a population. Reviewing the medical record so thoroughly like that can also tell us what kinds of medical tests an individual has after TBI, such as pictures of the brain or recordings of its electrical activity. This information can then be used to find out how changes in the brain caused by trauma might increase someone's risk for developing PTE or even how trauma causes PTE.

This kind of research requires reviewing thousands of medical records, which is extremely difficult and time-consuming. Mayo Clinic established the Rochester Epidemiology Project in the mid 1960s, linking all the medical records of everyone in the population of Olmsted County in Minnesota who consents, and has been doing exactly this sort of research since then. The scientists involved in this application have decades of experience specifically studying TBI and PTE in the entire population of Olmsted County. In this way, Mayo Clinic provides the unique resources and expertise that is required to determine how often PTE occurs after TBI and what might increase risk for developing PTE.

We will confirm how many individuals in Olmsted County had a TBI during the years 1985 through 2014, match them with individuals in Olmsted County of their same age and sex but who did not have TBI, and follow them through the year 2022 to see how frequently each group developed seizures. We estimate we will find more than 16,000 individuals during that period who had a TBI. We will then see if there are any features of brain imaging or electrical brain activity that might predict whether someone will get PTE after TBI. We hope this will help medical providers better counsel individuals with TBI about how likely they are to develop PTE and better understand what causes PTE so we can effectively prevent and treat it.