By: Angelica Velez
Brain Changes in Post-Traumatic Seizures
What are Post-Traumatic Seizures?
Brain injuries occur when neurons are harmed or destroyed. These injuries are considered traumatic brain injuries (TBIs) when the harm comes from external physical trauma (Montalvo, 2014). TBI is the third most common cause of epilepsy, and over 50% of people with severe TBI develop post-traumatic epilepsy (Sharma et al., 2021). Post-traumatic seizures (PTS) are seizures related to a previous head injury, typically occurring in the first week following the injury. Seizures occurring after that week are defined as post-traumatic epilepsy (PTE), with approximately 80% of patients with PTE begin having seizures within the first two years after injury.
Most post-traumatic seizures are focal and can become bilateral tonic-clonic seizures, meaning that they start in one area of the brain and can spread to involve the whole brain (Kiriakopoulos, 2022). Depending on severity and frequency, these seizures can become debilitating for those who have them.
Symptoms and Risk Factors
During a seizure, there is abnormal electrical activity in the brain. There are a variety of symptoms associated with seizures, including:
- Staring
- Unresponsiveness or loss of consciousness
- Stiffening or shaking of the body, legs, arms, or head
- Strange sensations, including sounds, tastes, visual images, feelings, thoughts, or smells
- Inability to speak or understand
(NHS.UK, 2020)
There are several factors that increase the risk of PTS, which include:
- Acute intracerebral hematoma: Bleeding into the brain tissue.
- Acute subdural hematoma: Bleeding into the space between the skull and the brain.
- Loss of consciousness for more than 30 minutes
- Younger age
- Increased severity of brain injury: More severe injuries have increased risks of seizures.
- Chronic alcoholism
Risk factors for PTE are like those of PTS but are not the same. These factors include:
- PTS: Those who have had PTS are more likely to develop PTE.
- Acute intracerebral hematoma
- Acute subdural hematoma
- Brain contusion: Bruising on the brain causing bleeding and swelling in the brain at that region.
- Age at time of injury older than 65 years
- Increased severity of brain injury
(Verellen & Cavazos, 2010)
Treatments
Post-traumatic seizures are typically treated with antiseizure medication, which helps lower the likelihood of progressing into post-traumatic epilepsy. It is important to control seizures as soon as possible to prevent further brain injury. When there is a recurrence of seizures after one week following the injury, long-term anticonvulsant treatment is recommended. Medications will vary based on seizure type and medical history.
(Kiriakopoulos, 2022)
Physical Trauma, Epilepsy, and the Brain
While brain changes from TBI depend on the type and severity of the trauma, there are several structural, functional, and chemical changes that may result in post-traumatic seizures. Closed head injuries may result in bleeding in the brain, brain bruising, brain swelling, lack of blood flow to the brain tissue, and injury to the white matter tracts of the brain. Penetrating injuries can also result in scars on the brain tissue, the outer layer of the brain, or its coverings (Kiriakopoulos, 2022).
Studies have also found that a disrupted blood-brain barrier, changes in astrocytes, and structural changes lead to seizure-provoking brain activity. The blood-brain barrier allows the blood vessels that supply the central nervous system to tightly regulate the movement of particles and cells between the blood and the brain. Blood-brain barrier disruption is associated with increased brain dysfunction and increases the chance of having slow-wave activity in the brain. Both effects increase the risk of PTE. Astrocytes are neural cells that respond to injuries by forming scar tissue to seal damaged areas from necrotic tissue and protect the remaining tissue (Anwer et al., 2021). The scar, however, increases the likelihood of having post-traumatic seizures, and the surgical removal of this type of scar may alleviate post-traumatic seizures (Xu et al., 2019). Additionally, animal studies have shown that increased risk of PTS is associated with changes in regions of the brain, such as the cortex, hippocampus, thalamus, and amygdala. Most patients with PTS showed temporal lobe injury and most patients who developed PTE also had temporal lobe injuries (Anwer et al., 2021).
Conclusion
Post-traumatic seizures may occur in anyone who has experienced a traumatic brain injury. This can happen after events such as motor vehicle accidents, combat, violent assault, sports, and many other sources of external physical trauma.
Post-traumatic seizures may be limited to a week following injury or may extend for years afterward. For some, these seizures last a lifetime.
The symptoms of post-traumatic epilepsy should not be ignored. If having seizures more than a week after a head injury, seek help and consult a medical professional. There are different medication and treatment options that can be arranged by a physician.
Resources
Anwer, F., Oliveri, F., Kakargias, F., Panday, P., Arcia Franchini, A. P., Iskander, B., & Hamid, P. (2021). Post-traumatic seizures: A deep-dive into pathogenesis. Cureus, 13(4), e14395. https://doi.org/10
.7759/cureus.14395
Kiriakopoulos, E. (2022) Traumatic brain injury, seizures, and epilepsy. Brain Injury Association of America. Retrieved from: https://www.biausa.org/public-affairs/media/tbi-seizures-and-epilepsy#:~:text=Most%20seizures%20(8%20out%20of,the%20entire%20brain%20(generalized).
Montalvo, E. (2014) Understanding post-traumatic epilepsy. Epilepsy Foundation. Retrieved from: https://www.epilepsy.com/stories/understanding-post-traumatic-epilepsy
National Health Service (2020). Symptoms – Epilepsy. National Health Services, United Kingdom. Retrieved from: https://www.nhs.uk/conditions/epilepsy/symptoms/
Sharma, S., Tiarks, G., Haight, J., & Bassuk, A. G. (2021). Neuropathophysiological mechanisms and treatment strategies for post-traumatic epilepsy. Frontiers in Molecular Neuroscience: Brain Disease Mechanisms. 14. https://doi.org/10.3389/fnmol.2021.612073
Verellen, R. M., & Cavazos, J. E. (2010). Post-traumatic epilepsy: an overview. Therapy (London, England : 2004), 7(5), 527–531. https://doi.org/10.2217/THY.10.57
Xu, S., Sun, Q., Fan, J., Jiang, Y., Yang, W., Cui, Y., Yu, Z., Jiang, H., & Li, B. (2019). Role of Astrocytes in Post-traumatic Epilepsy. Frontiers in Neurology, 10, 1149. https://doi.org/10.3389/fneu
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