Non-epileptic seizures (NES) are events that closely resemble epileptic seizures but have different origins. An electroencephalogram (EEG) is a key tool for distinguishing these events. Understanding their appearance on an EEG is important for accurate diagnosis, effective management, and ensuring individuals receive the most appropriate care.
Understanding Non-Epileptic Seizures
Non-epileptic seizures (NES), also known as functional seizures or psychogenic non-epileptic seizures (PNES), are episodes that resemble epileptic seizures. However, they are not caused by abnormal electrical activity in the brain. Instead, NES are often a physical manifestation of psychological or emotional distress, trauma, or stress. They can occur as an unconscious reaction to difficult thoughts or feelings, or in response to physical triggers. Unlike epileptic seizures, which involve uncontrolled electrical discharges, NES represent a functional disruption in brain activity.
How EEG Works in Seizure Diagnosis
An electroencephalogram (EEG) is a non-invasive test that measures and records the brain’s electrical activity. Electrodes placed on the scalp pick up these signals, which are displayed as wavy lines known as brain waves. During an epileptic seizure, the brain’s normal electrical patterns change, and the EEG records characteristic abnormal electrical discharges or “spikes.” An EEG helps identify where a seizure starts, how it spreads, and the type of epileptic seizure.
Why Non-Epileptic Seizures Differ on EEG
Non-epileptic seizures do not involve the abnormal electrical brain activity seen in epilepsy. During an NES event, the EEG recording typically appears normal. This absence of epileptic brain activity on the EEG during a seizure-like event is a key indicator of NES. In contrast, an epileptic seizure shows distinct, abnormal patterns of electrical activity on the EEG. While NES can mimic epileptic seizures physically, their normal brain electrical signals provide a clear distinction.
Accurate Diagnosis of Non-Epileptic Seizures
Accurate diagnosis of non-epileptic seizures requires more than a standard EEG. The primary method for confirming NES is video-EEG (VEEG) monitoring. This specialized test simultaneously records a patient’s behavior via video and their brain activity through EEG. VEEG allows clinicians to observe physical manifestations of a seizure event while confirming the absence of epileptic brain activity on the EEG. This simultaneous recording is considered the most reliable method for differentiating NES from epileptic seizures. A thorough clinical history from the patient and accounts from witnesses are also important components of the diagnostic process.
Managing Non-Epileptic Seizures
Management of non-epileptic seizures primarily focuses on addressing the underlying psychological or emotional factors contributing to the events. Treatment often involves psychotherapy, such as cognitive behavioral therapy (CBT), which helps individuals understand the connection between their thoughts, feelings, and physical symptoms. Counseling and stress management techniques are also employed to help patients cope with emotional distress. Anti-seizure medications, used for epilepsy, are ineffective for NES and are not the appropriate treatment. While other medications may manage co-occurring conditions like anxiety or depression, they do not directly treat the non-epileptic seizures.