Non-epileptic seizure

Non-epileptic seizures (NES), also called non-epileptic episodic events,^[1] are paroxysmal events that resemble epileptic seizures but do not involve abnormal, rhythmic discharges in the brain that define epilepsy.^[2] Some may arise from functional disruptions in brain activity, as seen in psychogenic non-epileptic seizures (PNES), a common subtype classified under functional neurological disorders. Others result from physiological causes, including fainting, sleep disorders, or movement disorders.^[3]

Non-epileptic seizures do not respond to anti-seizure medications.^[4] The gold standard for distinguishing them from epilepsy is video-electroencephalographic (video-EEG) monitoring. Management depends on the underlying cause: functional seizures are treated with psychological and rehabilitative therapies, while physiological mimics require targeted medical care.^[5]

Older terms such as pseudoseizure are now considered outdated and potentially pejorative. They have been discouraged by professional societies, including the International League Against Epilepsy (ILAE), due to their implications of falsification or triviality.^[6]

Non-epileptic seizures can arise from psychogenic (functional) or physiological causes.^[5]

The most common type of non-epileptic seizure encountered in neurology clinics is the functional seizure, also known as a psychogenic non-epileptic seizure (PNES) or dissociative seizure. These events are classified as a subtype of functional neurological disorder (FND), in which normal brain networks may be disrupted without structural damage or epileptic activity. Functional seizures are involuntary and may be associated with psychological distress, trauma, or dissociation, though not all patients have identifiable psychiatric conditions. The events often involve complex motor behaviors, unresponsiveness, or convulsions, and are frequently mistaken for epilepsy.^[6]

Physiological causes include a range of neurological and non-neurological conditions, such as:^[3][5][7]

• Syncope (fainting), including Reflex anoxic seizures.
• Breath-holding spells.
• Sleep-related disorders, such as parasomnias, narcolepsy with cataplexy,REM sleep behavior disorder and bruxism.
• Movement disorders (tics, paroxysmal kinesigenic dyskinesia, non-epileptic myoclonus).
• Hyperekplexia.
• Migraine and migraine-associated disorders.
• TIAs
• Opsoclonus myoclonus syndrome.
• Hypoglycemia.

NES symptoms are often similar to those of generalized tonic–clonic seizures, and may include convulsive movements, altered awareness, unresponsiveness, memory difficulties, loss of speech or sudden collapse, loss of bladder control, and others.^[8][9] The specific symptoms vary depending on the underlying cause, and no single sign can differentiate between types of physiologic or psychogenic NES, or between NES and epilepsy.^[5]

Diagnosis of NES requires careful evaluation to distinguish it from epilepsy, as treatments differ, and a failure to do so may lead to misdiagnosis and inappropriate use of anti-seizure medications. The gold standard for diagnosis is video-electroencephalographic (video-EEG) monitoring, which allows for simultaneous recording of behavior and brain activity.^[2][10] Additional tests may be performed depending on the suspected underlying cause. These can include electrocardiography (ECG) or tilt-table testing to evaluate for syncope, sleep studies for suspected parasomnias or narcolepsy, metabolic panels to identify electrolyte or glucose abnormalities, and neuroimaging to rule out structural brain lesions. Neuropsychological assessment may be useful in individuals with functional seizures, particularly when there is concern for cognitive or psychiatric comorbidities.

Some characteristics that are more prevalent in PNES than in epileptic seizures (potential "yellow flags") include gradual onset, unusual movements, atypical vocalization, eye closure with forceful resistance to opening, emotional triggers or context-specific occurrence, among others. None of these features alone are sufficient for diagnosis.^[10]

For physiological causes of non-epileptic seizures, treatment is directed at the underlying medical condition precipitating the episodes. For functional seizures (PNES), management focuses on clear communication of the diagnosis and a multidisciplinary approach, including evidence-based psychological therapies and patient education. Cognitive behavioral therapy (CBT) has the strongest evidence to date, with additional support for trauma-focused therapies and physical rehabilitation approaches. Discontinuation of anti-seizure medications may be appropriate if epilepsy has been excluded.^[11]

• What are Non-Epileptic Seizures? Archived 2013-05-09 at the Wayback Machine from Cleveland Clinic