A traumatic brain injury (TBI) is one of the most significant injuries a person can sustain. The resulting trauma can lead to a variety of symptoms and secondary conditions such as short- and long-term memory loss, personality or mood changes, pain, lethargy, confusion, vomiting, and even seizures or epilepsy, which is a seizure disorder.
Different types of head injuries include:
- Closed head injuries, or injuries that have no visible bleeding or open wounds because the damage occurs inside the skull. These injuries can result in internal bleeding and contusions (bruises) of the brain.
- Open wound injuries, or wounds that penetrate the skull; and
- Crushing injuries, which is when the head and brain are compressed between two solid objects. These types of injuries frequently damage the brain stem and neck.
In many cases, having a seizure after hitting your head hard enough to cause a traumatic brain injury is not uncommon. But, what are seizures and why do they happen? And, is there a link between seizures and traumatic brain injury?
What Are Seizures?
In a nutshell, a seizure is the result of abnormal electrical activity — or a surge of electrical activity — in the brain. In some cases, seizures are caused by congenital conditions or environmental factors such as flashing lights and repetitive sounds; in others, they can result from traumatic brain injuries. You can also suffer a seizure after hitting your head — even if there appears to be no external damage to the head or skull.
According to research from TBI Model System Centers, as cited by the National Rehabilitation Information Center (NARIC):
“Several pre-TBI factors were related to seizure risk. The participants who had pre-existing health conditions affecting their ability to learn, remember, or concentrate, such as learning disabilities or emotional disorders, were more likely to have seizures in the hospital than those without these conditions. During the follow-up period, the participants who had mental health conditions before their TBI, or who had been incarcerated before their TBI, were also more likely to have seizures. However, having more than one moderate-to-severe TBI did not affect seizure risk.”
Regardless of the cause, WebMD reports that there are two main types of seizures:
- Focal seizures: Also known as partial seizures, these episodes start in a particular part of your brain — but may spread to other areas. These seizures can cause emotional and physical effects, resulting in sensing (feeling, hearing, seeing, etc.) things that aren’t there. These types of seizures are divided into three categories: simple, complex, and secondary.
- Generalized seizures: These episodes occur when the nerve cells within your brain misfire and can cause blackouts, muscle spasms, and falls. There are six types of generalized seizures: clonic, tonic, tonic-clonic (also known as a grand mal seizure), atonic, myoclonic, and absence (also known as a petit mal seizure).
No two seizures or brain injury seizures are identical; every seizure affects each person differently because the condition impacts different lobes of the brain that are responsible for different behaviors, experiences, and movements. For some, seizures may go unnoticed and result in no visible physiological response. In more severe cases, they can result in unconsciousness, convulsions, and self-injuries (biting your tongue or lips, hitting your head, etc.).
Seizures can occur suddenly, or you may experience similar events or feelings leading up to a seizure that can serve as warning signs — occurrences known as preictal auras.
The Link Between Seizures and Traumatic Brain Injury
According to 2016 statistics from NARIC, 2.5 million Americans are estimated to sustain traumatic brain injuries each year. These types of severe injuries can set off “chain reactions” in the brain. Brain injury seizures can result from one or more of the following:
- The development of bruising and glial scar tissue,
- A lack of oxygen to the brain, and/or
- The deaths of neurons (brain cells).
Brain injury seizures in the days following a TBI are not uncommon and are known as early post-traumatic seizures (PTS). According to the Model Systems Knowledge Translation Center (MSKTC), one in 10 people who require hospitalization after a TBI will experience seizures. (Depending on the resource, this number can increase to 1-5 out of every 10 individuals with TBIs.) Seizure activity that occurs more than a week after the initial injury (known as a late post-traumatic seizure) qualify as epilepsy or, more specifically, post-traumatic epilepsy (PTE). This means that there is likely a link between traumatic brain injury and epilepsy.
According to a 2015 study in Seizure on traumatic brain injury and epilepsy, “traumatic brain injury (TBI) is a leading cause of acquired epilepsy,” and post-traumatic epilepsy accounts for 10–20% of epilepsy cases in the general population.
Expectations Concerning Seizures After Traumatic Brain Injury
When it comes to understanding the underlying causes of PTE and the full effects of it, there are differing opinions in the medical community. For example, the earlier cited Seizure study indicates that despite prophylaxis treatment, which is used to prevent a single occurrence of acute post-traumatic seizure (PTS), 4-53% of TBI patients still suffer chronic seizures.
There is good news, however, for people who are living with the results of seizures and traumatic brain injury: According to 2014 research published in Archives of Physical Medicine and Rehabilitation, “About 70-80% of people who have seizures are helped by medications, and can return to usual activities. Rarely, seizures can make you much worse or even cause death.”
There is still a lot for the science and medical communities to learn about the link between seizures and traumatic brain injury. To learn more about living with a traumatic brain injury, download our complimentary resource now by clicking on the link below.
