A seizure is a temporary and involuntary disturbance of behavior, sensation, or consciousness. While they may appear similar on the surface, not all seizure-like events share the same origin. Distinguishing between different types of seizures is an important step in determining the correct course of action, as the underlying causes dictate vastly different approaches to management and care.
The Nature of Epileptic Seizures
Epileptic seizures are the direct result of abnormal and excessive electrical discharges occurring among the brain’s nerve cells, known as neurons. These sudden bursts of electrical activity disrupt normal brain function, leading to the outward signs of a seizure. The specific manifestation of the seizure depends on which part of the brain is affected by this electrical storm. For instance, if the electrical focus is in the motor cortex, it might produce jerking movements in a limb.
Epilepsy is a neurological condition defined by an enduring predisposition to generate recurrent, unprovoked seizures. This means the brain has a persistently lowered threshold for seizure activity, making it susceptible to these electrical disruptions without an immediate trigger. The transition from normal brain activity to a seizure, called the ictal phase, happens when the brain’s inhibitory controls are overwhelmed by a surge of excitatory signals. This imbalance allows the abnormal firing to spread to other parts of the brain.
The underlying reasons for this chronic hyperexcitability can vary, including genetic predispositions, structural changes in the brain from injury, or imbalances in neurotransmitters. Neurotransmitters are the chemical messengers that neurons use to communicate. Reduced function of inhibitory neurotransmitters or overactivity of excitatory ones can create a state where neurons are more easily triggered. This chain reaction among a large population of neurons is what constitutes the epileptic seizure.
Understanding Non-Epileptic Seizures
Non-epileptic seizures (NES) are episodes that closely mimic the physical appearance of epileptic seizures but are not caused by abnormal electrical activity in the brain. These events are real and involuntary, meaning the individual is not consciously producing the symptoms. Because they do not stem from electrical disturbances, they require a different diagnostic and treatment approach. NES are broadly divided into two main categories based on their underlying cause.
The most common type of NES is the psychogenic non-epileptic seizure (PNES), also referred to as a functional or dissociative seizure. These events are physical manifestations of underlying psychological distress, often linked to conditions such as anxiety, depression, or past traumatic experiences. PNES is a complex communication issue between the mind and body, not a deliberate act of faking illness. The seizure-like episode is the body’s way of responding to overwhelming stress.
A second category is physiologic non-epileptic seizures, which are caused by other medical conditions that produce seizure-like symptoms. For instance, a sudden drop in blood flow to the brain due to a heart arrhythmia can cause fainting (syncope) with brief jerking movements. Other causes can include sleep disorders, metabolic problems like low blood sugar, and certain movement disorders. The event is a symptom of a separate physiological issue, not a primary brain disorder.
Key Distinctions in Presentation and Triggers
While epileptic seizures and psychogenic non-epileptic seizures (PNES) can appear similar, there are often subtle but consistent differences in their presentation. One of the most cited distinctions is the state of the eyes. During many types of epileptic seizures, the eyes are open, whereas in PNES, the eyes are often forcefully closed.
The character of the movements also provides important information. Epileptic seizures, particularly generalized tonic-clonic types, often involve a phase of stiffening followed by rhythmic, synchronized jerking of the limbs. In contrast, movements during PNES can appear more chaotic and may include side-to-side head shaking, asynchronous limb movements, or pelvic thrusting.
Vocalization and the duration of the event are other differentiating factors. While a brief cry can occur at the onset of an epileptic seizure, coherent speech or continuous weeping is more characteristic of PNES. Epileptic seizures are brief, usually lasting less than three minutes, while PNES episodes can be much longer.
Triggers and the post-event state also diverge. While epileptic seizures can be triggered by factors like flashing lights, they often occur without clear provocation. PNES, however, are frequently precipitated by a recognizable emotional or stressful event. Following a generalized epileptic seizure, there is a post-ictal period of confusion and exhaustion, while recovery after a PNES episode is often much faster.
The Diagnostic Evaluation
Differentiating between epileptic and non-epileptic seizures requires a thorough diagnostic process. The evaluation begins with a detailed medical history and eyewitness accounts. Family members or friends who have witnessed the seizures can provide descriptions of the person’s movements, responsiveness, and recovery period.
The definitive diagnostic tool is video-electroencephalography (vEEG) monitoring. This procedure is considered the gold standard because it simultaneously records the patient’s brainwave activity with an EEG and their physical actions on video. This typically requires a hospital stay in a specialized epilepsy monitoring unit (EMU) for several days to capture one of the patient’s typical events.
This simultaneous recording allows neurologists to make a direct correlation between the physical event and the brain’s function. If the video captures a seizure and the EEG shows corresponding abnormal electrical discharges, a diagnosis of epilepsy is confirmed. Conversely, if a typical event occurs but the EEG remains normal, it strongly indicates that the seizure is non-epileptic.
Divergent Treatment Pathways
The treatment for seizures depends entirely on their origin. For epileptic seizures, the primary treatment involves anti-seizure medications (ASMs). These medications work by stabilizing the electrical activity of neurons to make them less likely to fire abnormally. In cases where medications are not fully effective, other options may include specialized diets, neurostimulation devices, or surgery to remove the seizure focus.
In contrast, anti-seizure medications are ineffective for non-epileptic seizures. For psychogenic non-epileptic seizures (PNES), treatment focuses on addressing the underlying psychological distress. The most recommended approach is psychological therapy, such as Cognitive Behavioral Therapy (CBT). CBT helps individuals identify triggers and develop healthier coping mechanisms.
For physiologic non-epileptic seizures, treatment is directed at managing the underlying medical condition. If seizure-like events are caused by a heart condition, a cardiologist would manage the cardiac issue. If they are related to metabolic disturbances like diabetes, an endocrinologist would work to stabilize blood sugar levels. A correct diagnosis is the gateway to the right treatment, ensuring patients receive appropriate care.