September 22, 2023

Takeaway highlights:

  1. Traumatic brain injury (TBI), even of mild severity, can lead to an increased risk of post-traumatic epilepsy (PTE).
  2. The risk of PTE is higher the more severe the head injury, with hemorrhage on head CT imaging further increasing this risk.
  3. Among patients with TBI, 19.4% experienced seizure activity, with early post-traumatic seizures (EPTS) and late post-traumatic seizures (LPTS) both being observed.
  4. Patients who developed seizures after TBI more frequently had an evacuated mass lesion, compound skull fracture, and underwent neurosurgical interventions.
  5. Even mild TBI was associated with a 3.1 times higher risk of epilepsy in the first year, falling to a two-fold risk in years 1-4, and returning to normal population levels by the fifth year.
  6. Severe TBI led to an extremely high risk of PTE (96.9 times higher than normal) in the first year, falling over time but remaining four times higher than the normal population 10 years post-injury.
  7. The use of prophylactic antiepileptic drugs in patients with TBI does not appear to reduce the risk of PTE and may worsen outcomes.
  8. Those with TBI and PTE have significantly worse outcomes than those with TBI without PTE, as measured by several scales assessing mood, cognitive function, and overall health.

Traumatic brain injuries (TBIs), even those classified as mild, have been increasingly recognized as a risk factor for post-traumatic epilepsy (PTE). Recent studies have shed light on the connection between mild TBI and the subsequent development of epilepsy, providing valuable insights into this serious medical concern.

The analysis by Anneger’s et al. provides an even more detailed understanding of the risk of epilepsy following traumatic brain injury (TBI) of varying severities. It underscores the key conclusion that the risk of post-traumatic epilepsy (PTE) is greater the more severe the TBI is, and this risk decreases over time.

Following a mild TBI, the risk of epilepsy is 3.1 times higher than normal population levels within the first year, falling to a two-fold increase in the 1-4 year period after the injury. Intriguingly, by the fifth year post-injury, the risk of epilepsy appears to return to normal population levels. This suggests that while the risk of PTE is certainly elevated following a mild TBI, this risk diminishes over time, eventually returning to baseline levels.

In contrast, following a severe TBI, the risk of PTE is dramatically higher. In the first year after such an injury, the risk of epilepsy is a staggering 96.9 times higher than the normal population. This risk falls over time, but even 10 years after the injury, those who have experienced a severe TBI still have a risk that is four times higher than the normal population.

These findings provide valuable insights for healthcare providers managing patients with TBIs of different severities. They highlight the need for careful monitoring and management of epilepsy risk in the years following a TBI, particularly for those with more severe injuries. The data also underscores the importance of ongoing research to understand the mechanisms underlying PTE and to develop effective strategies for prevention and treatment.

It’s also worth noting the risk for PTE following moderate TBI, which is 6.5 times higher compared to normal population levels in the first year, falling to 3.1 in years 1-4, to 3 in years 5-9, and to 1.8 in year 10 and onwards. This indicates a persistent increased risk of PTE even 10 years post-injury, but at a level that’s significantly lower than that seen after severe TBI.

Taken together, these statistics emphasize the significant and lasting impact that TBIs of all severities can have on an individual’s risk of developing epilepsy. It underscores the critical need for effective strategies to prevent TBIs and to manage their aftermath, including the increased risk of epilepsy.

A 2022 study published in Nature reported that out of 341 adult patients with mild-to-severe TBI, 19.4% had reported or documented seizure activity during the observation period from acute care to inpatient rehabilitation​. Patients who developed seizures were more frequently found to have an evacuated mass lesion and a higher prevalence of compound skull fracture, and they more regularly underwent craniotomy and/or cranioplasty​.

The study further analyzed patients with epilepsy according to the type of seizure, finding that early post-traumatic seizure (EPTS) patients had a significantly higher frequency of diffuse injury grade III and of compound skull fracture than patients without epilepsy. Late post-traumatic seizures (LPTS) patients had more frequently undergone craniotomy and cranioplasty and had a lower Glasgow Coma Scale (GCS) and Functional Independence Measure (FIM) on discharge​.

In a multicenter, prospective cohort study mentioned in Medscape, it was found that even a mild TBI could lead to PTE up to a year after the head injury occurs. Out of nearly 1500 participants with TBI, 2.7% reported also having PTE, and these patients had significantly worse outcomes than those without PTE​.

Interestingly, the study found that some patients with milder brain injuries were also at increased risk for epilepsy. Furthermore, the risk for PTE was higher the more severe the head injury and among those with haemorrhage on head CT imaging. In patients with mild TBI, haemorrhage was associated with a two- to threefold risk of developing PTE​.

Moreover, compared to those who had TBI but not PTE, those with PTE had significantly lower Glasgow Outcome Scale Extended (GOSE) scores, higher Brief Symptom Inventory (BSI) scores, and higher Rivermead Cognitive Metric (RCM) scores at 12 months after controlling for age, initial GCS score, and imaging findings​.

Current evidence suggests that the prophylactic use of antiepileptic drugs in patients with TBI does not reduce risks. Some studies showed that specific agents could worsen outcomes, underlining the need for careful consideration of therapeutic strategies for these patients​.

In summary, recent literature underscores the potential risk of epilepsy following even mild traumatic brain injuries. This connection warrants further research to understand the pathophysiological mechanisms at play better and develop effective strategies to mitigate the risk and improve patient outcomes.

Literature

  1. Annegers JF, Coan SP. The risks of epilepsy after traumatic brain injury. Seizure. 2000 Oct;9(7):453-7. doi: 10.1053/seiz.2000.0458. PMID: 11034867.
  2. Tassinari, C. A., Rubboli, G., Volpi, L., Meletti, S., d’Orsi, G., Franca, M., Sabetta, A. R., Riguzzi, P., Gardella, E., Zaniboni, A., Michelucci, R., & Tinuper, P. (2022). Post-traumatic epilepsy: current concepts and future perspectives. Nature. Link
  3. Brooks, M. (2022). Even Mild TBI Can Increase Risk for Post-traumatic Epilepsy. Medscape. Link

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