A seizure is a sudden, uncontrolled electrical disturbance in the brain, causing temporary changes in behavior, movement, feelings, or consciousness. This abnormal electrical activity disrupts the brain’s normal communication pathways. When a fall causes a traumatic brain injury (TBI), the resulting physical and chemical disruption can trigger a seizure, known as a provoked or acute symptomatic seizure. The relationship between a fall and a seizure is complex, however, because the sequence of events can be reversed, making immediate diagnosis challenging.
Acute Seizures Following Head Trauma
A fall that results in a traumatic brain injury can lead to an acute symptomatic seizure, defined as an event occurring within the first seven days of the injury. Physical trauma, such as a severe blow to the head, can cause immediate damage to brain tissue. This damage may involve bruising of the brain, known as a cerebral contusion, or bleeding within the skull, such as an intracranial hematoma.
The presence of blood or swelling directly irritates the brain’s surface, triggering an abnormal electrical discharge. Blood products, like iron, can disrupt the balance of chemicals that regulate nerve cell firing. Approximately 10% of people who experience a traumatic brain injury will have an acute seizure. This risk correlates directly with the severity of the TBI; moderate to severe injuries pose a much greater danger than mild concussions. Severe injuries involving skull fractures, a depressed skull, or penetrating trauma significantly increase the likelihood of an immediate seizure.
Determining if the Seizure Caused the Fall
A crucial challenge for medical professionals is determining whether the fall caused the head injury and subsequent seizure, or if a seizure caused the person to lose consciousness and fall. Seizures can cause sudden loss of muscle tone (atonic seizures) or full-body stiffening and jerking (tonic-clonic seizures), both of which result in an abrupt, unwitnessed fall. Fainting, or syncope, which is a temporary drop in blood flow to the brain, is another common cause of falling that may look like a seizure.
The period immediately following the event, known as the post-ictal phase, provides important diagnostic clues. After a seizure, a person often experiences a prolonged period of confusion, drowsiness, and disorientation, sometimes lasting hours. Conversely, after a syncopal episode, recovery is usually very rapid, with the person regaining full awareness within minutes. A seizure may also be preceded by an “aura,” which involves strange sensations, smells, or visual disturbances.
Developing Long-Term Epilepsy After Injury
If a person experiences recurrent, unprovoked seizures more than seven days after head trauma, they are diagnosed with Post-Traumatic Epilepsy (PTE). This condition results from permanent changes in the brain that create an ongoing vulnerability to seizures. The risk of developing PTE is far greater after a severe TBI, especially in cases of penetrating head injuries where the incidence can be as high as 50%.
The underlying mechanism involves a process called epileptogenesis, where the injury leads to long-term structural reorganization. Scar tissue formation, known as gliosis, occurs as brain support cells react to the damage. This scarring can alter the brain’s circuitry, disrupting the balance between excitatory and inhibitory signals. Intracranial bleeding, especially intracerebral hemorrhage, is a strong predictor of developing PTE, as the blood products continue to irritate the tissue over time.
When Immediate Medical Help Is Needed
Any person who experiences a seizure following a fall and head injury should receive prompt medical evaluation. The most urgent situation is a convulsive seizure that lasts five minutes or longer, a condition called status epilepticus, which can cause permanent brain damage. Emergency medical services should be called immediately if the person has repeated seizures without regaining consciousness between episodes.
Other red flags include difficulty waking up, persistent confusion, or severe injury resulting from the fall itself. A first-time seizure always warrants a medical check-up to identify the cause and prevent recurrence. Even if the seizure is brief, a fall-related head injury carries a high risk of complications that requires urgent imaging and assessment.