Can Brain Injury Cause Seizures? What Families Need

A person can look mostly fine after a fall, blast exposure, vehicle crash, or sports impact - then have a seizure hours, days, or months later. That is frightening, and it can leave a family wondering whether they missed something. Can brain injury cause seizures? Yes. A traumatic brain injury can disrupt the brain enough to trigger seizures, either near the time of injury or later on. But injury does not mean seizures are inevitable, and one unusual episode does not automatically mean epilepsy. [National Institute of Neurological Disorders and Stroke, Traumatic Brain Injury; Annegers et al., New England Journal of Medicine, 1998]

For caregivers and veteran families, the practical question is not just why this happens. It is what to watch for, what to do in the moment, and when to push for answers without getting brushed off.

Can brain injury cause seizures right away or years later?

Both can happen. Clinicians generally describe seizures occurring within seven days of a traumatic brain injury as early post-traumatic seizures. Seizures that begin more than seven days after the injury are called late post-traumatic seizures. Recurrent unprovoked seizures after a brain injury may lead a clinician to diagnose post-traumatic epilepsy. [Lowenstein, Epilepsia, 2009; Annegers et al., New England Journal of Medicine, 1998]

The timing matters because an early seizure may be tied to the immediate chaos inside the injured brain: bleeding, swelling, bruising, or metabolic stress. A later seizure can reflect longer-term changes in brain networks after healing and scarring. That explanation may sound technical, but the point is plain: a brain injury is not always a one-day event. The effects can keep unfolding after the emergency room discharge papers are gone and everyone else expects life to be “back to normal.” [Lowenstein, Epilepsia, 2009]

Risk is higher after more severe injuries, penetrating injuries, bleeding inside the skull, depressed skull fractures, prolonged loss of consciousness, and an early seizure. Still, risk exists on a spectrum. A mild concussion is not the same as a severe combat injury or a major car crash, and most people with a mild injury will not develop post-traumatic epilepsy. [Annegers et al., New England Journal of Medicine, 1998; Englander et al., Archives of Physical Medicine and Rehabilitation, 2003]

A seizure does not always look like a collapse

The version most people picture is a convulsive seizure: a person falls, stiffens, jerks, may lose awareness, and is exhausted afterward. That can happen. But seizures can also be quieter and easier to mistake for panic, intoxication, a PTSD response, confusion, or “just another bad day.” [National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy]

A loved one may suddenly stare and not respond, stop speaking mid-sentence, smack their lips, pick at clothing, wander, repeat the same phrase, or seem intensely confused for a few minutes. Some people experience a warning before a seizure, such as a strange smell or taste, a wave of fear, nausea, déjà vu, or an odd sensation rising through the body. Others have no warning at all. [National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy]

None of those signs proves a seizure. Medication effects, sleep deprivation, low blood sugar, infection, substance withdrawal, fainting, migraine, and functional neurological symptoms can overlap with seizure-like events. This is why a clear description from someone who witnessed the episode can be more useful than a vague label. [National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy]

If it is safe, write down what happened before, during, and after the episode: the time it started, body movements, eye position, breathing or color changes, whether the person could respond, injuries, and how long it took them to return to baseline. A brief phone video can also help a medical team sort out what they are seeing, but safety comes first. Do not delay help to document an emergency. [National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy]

What to do if someone is having a seizure

The goal is simple: keep them safe, protect their dignity, and get emergency help when the situation calls for it. You cannot force a seizure to stop by holding someone down, yelling their name, or putting something in their mouth. In fact, those actions can cause harm. [Centers for Disease Control and Prevention, Seizure First Aid]

If a person is convulsing, ease them to the floor if possible, move hard or sharp objects away, cushion their head, loosen anything tight around the neck, and turn them gently onto their side when you can. Time the seizure. Stay with them until they are awake enough to be safe. [Centers for Disease Control and Prevention, Seizure First Aid]

Call 911 if the seizure lasts more than five minutes, another seizure begins before recovery, breathing is difficult afterward, the person is injured, the seizure happens in water, the person is pregnant, or this is their first known seizure. Call as well if your gut says something is seriously wrong. Caregivers are often told to ignore their instincts. You do not need to do that here. [Centers for Disease Control and Prevention, Seizure First Aid]

Afterward, the person may be confused, angry, tearful, sore, embarrassed, or deeply tired. That recovery period is called the postictal state, and it can last minutes to hours depending on the person and the seizure. Keep your language calm and short. “You had a seizure. You are safe. I am here.” That is enough for the moment. [National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy]

When to contact the medical team

A first seizure after any head injury deserves prompt medical evaluation, even if the person appears to recover. Emergency care is especially urgent after a recent injury or when there are red flags such as worsening headache, repeated vomiting, new weakness, unequal pupils, increasing confusion, or difficulty staying awake. These symptoms can signal a potentially dangerous complication of traumatic brain injury. [Centers for Disease Control and Prevention, Signs and Symptoms of Concussion; National Institute of Neurological Disorders and Stroke, Traumatic Brain Injury]

Evaluation may include a detailed history, neurological exam, blood testing, brain imaging, and an EEG, which records electrical activity in the brain. A normal EEG does not by itself rule out epilepsy, and an abnormal EEG does not replace the full clinical picture. Diagnosis usually depends on putting the story, exam, testing, and injury history together. [National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy]

Some people with severe traumatic brain injury receive anti-seizure medication for a short period to reduce early seizures. Research and clinical guidelines support short-term prevention in selected patients, but these medicines have not been shown to prevent late post-traumatic epilepsy for everyone. That trade-off matters: medication decisions should account for the type of injury, seizure history, side effects, other prescriptions, and the person’s day-to-day safety needs. [Carney et al., Neurosurgery, 2017]

For veteran households, be direct about blast exposure, prior concussions, sleep problems, alcohol or substance use, PTSD symptoms, and every medication or supplement in the mix. Those details are not moral failures and they are not “too much information.” They can change what the clinician needs to investigate and how a treatment plan is built. [National Institute of Neurological Disorders and Stroke, Traumatic Brain Injury]

The caregiving part nobody puts on the discharge sheet

Seizure risk can make ordinary life feel like a minefield: showers, stairs, cooking, driving, childcare, work shifts, and the fear of leaving someone alone. The answer is not to turn the whole house into a prison. It is to make a plan that matches the actual risk.

Ask the care team what activities should be paused, whether a rescue medication plan is appropriate, who should be called after an event, and what recovery looks like for your person. Keep the plan where tired people can find it. Tell a few trusted people what to do. If the person agrees, make sure workplace or family supports understand that a seizure may look confusing before it looks dramatic.

And caregiver, take this seriously: you are allowed to be scared. You are also allowed to need sleep, backup, and a second set of hands. At Robbins Nest Alliance, we believe clear information should not come with a lecture or a white coat translation problem. Learn the safety steps, document what you see, and keep advocating. You do not have to carry the whole neurological storm alone.

Sources

Annegers JF, et al. “A Population-Based Study of Seizures After Traumatic Brain Injuries.” New England Journal of Medicine. 1998.

Carney N, et al. “Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition.” Neurosurgery. 2017.

Centers for Disease Control and Prevention. “Seizure First Aid” and “Signs and Symptoms of Concussion.”

Englander J, et al. “Risk Factors for Late Posttraumatic Seizures After Traumatic Brain Injury.” Archives of Physical Medicine and Rehabilitation. 2003.

Lowenstein DH. “Epilepsy After Head Injury: An Overview.” Epilepsia. 2009.

National Institute of Neurological Disorders and Stroke. “Seizures and Epilepsy” and “Traumatic Brain Injury.”