The relationship between a fall and a seizure is complex, as the sequence of events can flow in two different directions. A seizure is a sudden, uncontrolled electrical disturbance in the brain that temporarily affects how a person behaves or functions. While many people assume a fall causes a seizure, a neurological event frequently causes the fall, making the fall a secondary consequence. Understanding which event came first is crucial for correct medical diagnosis and treatment.
Understanding the Inverse: When a Seizure Causes the Fall
The most common scenario is when a seizure or seizure-like event directly causes a person to fall. Generalized tonic-clonic seizures involve sudden loss of consciousness, muscle stiffening, and jerking, leading to an uncontrolled collapse. Atonic seizures cause a sudden and complete loss of muscle tone, often called a “drop attack.”
Beyond seizures, other medical conditions causing sudden loss of consciousness can also trigger a fall. Syncope (fainting) results from a temporary drop in blood flow to the brain. When a fall results from these events, the injury sustained is a consequence of the underlying neurological or cardiac problem.
When a fall is caused by a seizure, the person is at high risk for serious physical injuries, especially head trauma. People who fall due to a seizure are significantly more likely to suffer traumatic intracranial hematomas (collections of blood within the skull). The uncontrolled nature of the fall prevents protective reflexes from cushioning the impact.
Acute Seizures Following Head Trauma
A fall resulting in a traumatic brain injury (TBI) can cause an acute symptomatic seizure. These seizures occur within the first seven days following the fall and are a direct reaction to the acute insult to the brain tissue.
The physical force of hitting the head can cause immediate damage, such as brain contusions, intracranial bleeding, or swelling. This disruption irritates brain cells, altering the electrical and chemical environment. About 50% of these early seizures occur within the first 24 hours after the injury.
The severity of the TBI is directly related to the risk of an acute seizure. Injuries involving longer loss of consciousness, a depressed skull fracture, or bleeding into the brain tissue significantly increase this likelihood. These seizures are typically generalized tonic-clonic seizures. While serious, they do not automatically mean the person has developed long-term epilepsy.
Developing Epilepsy After Injury
Separate from the immediate reaction, a severe fall resulting in a TBI can lead to the long-term development of post-traumatic epilepsy (PTE). PTE is characterized by recurrent, unprovoked seizures occurring more than one week after the initial injury. This chronic condition involves lasting changes to the brain’s structure, a process called epileptogenesis.
The damage initiates biological responses, including inflammation and the formation of scar tissue (gliosis) in the injured area. This scar tissue and altered neural networks can become hyper-excitable, creating a focus for abnormal electrical discharges months or years later. The median time for PTE onset is around two years, but it can range up to 15 years after the trauma.
The risk of developing PTE is highest following severe TBI, defined by factors like penetrating head injuries, substantial intracranial hematomas, or early seizures within the first week. For patients with severe TBI, the cumulative incidence of PTE can be as high as 32% at fifteen years. The occurrence of an early symptomatic seizure is a strong predictor, significantly increasing the risk of later epilepsy.
Immediate Steps and Medical Assessment
Any fall involving a loss of consciousness, a witnessed seizure, or a significant head impact requires immediate medical assessment.
Warning Signs
Warning signs necessitating an emergency room visit include:
- Repeated seizures.
- A severe and persistent headache.
- Confusion that worsens over time.
- Any signs of bleeding.
Even if the person recovers quickly, a medical evaluation is necessary to rule out serious internal injuries.
Diagnostic Tools
Healthcare providers use a variety of diagnostic tools to determine the cause and extent of the injury. A computed tomography (CT) scan is used in the emergency setting to rapidly check for acute issues like bleeding or skull fractures. A magnetic resonance imaging (MRI) scan provides detailed images of the brain’s soft tissues, helping to identify smaller abnormalities or areas of contusion.
An electroencephalogram (EEG) is the primary tool for evaluating the electrical activity of the brain, recording brain waves through electrodes placed on the scalp. This test helps confirm if an event was a seizure and can show abnormal patterns suggesting a risk for future seizures. Blood tests are also standard to check for metabolic causes of a fall or seizure, such as low blood sugar or electrolyte imbalances.