Psychogenic non-epileptic seizures (PNES), also referred to as functional seizures or dissociative seizures, are paroxysmal episodes of impaired or altered consciousness, abnormal movements, and/or sensory symptoms. They may superficially resemble epileptic seizures but are not caused by abnormal electrical activity in the brain. Instead, they are classified as a type of functional neurological disorder (FND), in which symptoms may arise from changes in brain function rather than structural disease or hypersynchronous neural activity as seen in epilepsy. During a PNES episode, seizure-like behavior occurs in the absence of epileptiform activity on electroencephalogram (EEG). PNES has previously been referred to as pseudoseizures, although this terminology has fallen out of favor due to associated stigma.
PNES can be difficult to distinguish from epileptic seizures based on clinical observation alone. Diagnosis is typically confirmed through video-EEG monitoring, which records both the clinical event and the absence of epileptiform activity. These episodes are involuntary and genuine, not consciously produced. Management primarily involves psychological treatment, particularly cognitive behavioral therapy (CBT). Outcomes vary and may be influenced by factors such as early diagnosis, therapeutic engagement, and coexisting psychiatric conditions.
Signs and symptoms PNES episodes involve sudden changes in movement, sensation, or awareness that closely resemble epileptic seizures. During an episode, a person may exhibit convulsive movements (such as stiffening, jerking, or thrashing of the limbs), appear unresponsive, or display other seizure-like behaviors. Because of this resemblance, PNES can be difficult to distinguish from epilepsy without careful observation and diagnostic tools, such as long-term video-EEG monitoring.
Certain features are more commonly seen in PNES than in epileptic seizures, although none are exclusive. These may include eye closure or fluttering during the event, side-to-side movements of the head or body, pelvic thrusting, arching of the back, limb movements that are asynchronous or irregular, and crying or stuttering. People with PNES may also show signs of awareness, respond to touch or voice, or behave in ways that appear influenced by their surroundings. PNES episodes also tend to begin more gradually than epileptic seizures, and typically do not result in confusion or deep sleep afterward (postictal state), which is common following epileptic seizures. The shaking seen in PNES tends to be less likely to be rhythmic or synchronous, such as in epileptic seizures. Also, PNES episodes tend to be longer in duration compared to epileptic seizures. Most epileptic seizures are less than 2 minutes in duration, whereas PNES episodes can last much longer and, in some cases, may go on for hours. An epileptic seizure lasting more than five minutes is considered a life-threatening medical emergency, a risk not associated with PNES.
PNES episodes also tend to result in less severe physical injuries. Complications such as tongue-biting, loss of bladder or bowel control, and severe falls are less common. However, many people with PNES still face injuries from falls and may have loss of bladder control. Even when a person appears unresponsive, they may retain some awareness and instinctively protect themselves. Signs such as tracking movement with the eyes or the ability to blink and/or swallow on command can suggest preserved consciousness. These features may support the diagnosis of PNES, although no single sign is definitive. Patients with PNES are generally recommended to abstain from driving since an episode while operating a vehicle may result in a crash or injury. Laws with respect to driving may differ in different jurisdictions.
Causes The causes of PNES are not well understood and are complex, and not linked to a single underlying mechanism. A biopsychosocial framework considers the interaction of psychological, neurobiological, and social factors. These influences are often described in terms of predisposing, precipitating, and perpetuating factors.
Predisposing factors are those that increase vulnerability, such as trauma history, psychiatric symptoms, somatic symptoms, and neurobiological factors. Precipitating factors are events that occur near the time of symptom onset, such as acute psychological stress, interpersonal conflict, or stress related to physical illness or injury. Perpetuating factors are those that contribute to the continuation of symptoms after they begin. These may include misdiagnosis as epilepsy, ongoing psychiatric comorbidities, and social or behavioral reinforcement of illness, among other factors.
According to a 2016 review, there is insufficient evidence to conclude that PNES has a psychogenic cause, as existing evidence fails to establish causality, and suffers from limitations such as a reliance on retrospective self-reports and clinical features not unique to psychogenic conditions.
PNES episodes are not consciously produced and are not under voluntary control. They are distinct from conditions such as malingering or factitious disorder, in which symptoms are intentionally fabricated or induced.
An estimated 10–30% of individuals with PNES also have coexisting epilepsy, which can complicate both diagnosis and treatment.
Comorbidities Mental health conditions
Psychiatric disorders are prevalent in patients with PNES. These include post-traumatic stress disorder (PTSD), anxiety disorders, mood disorders, major depressive disorder (MDD), and/or personality disorders. One of the predominant personality disorders observed in patients with PNES is borderline personality disorder or its traits, with overlapping characteristics such as a history of childhood trauma, emotional dysregulation, and challenges with interpersonal relationships. Other personality disorders that have also been reported include avoidant, dependent, or obsessive-compulsive types. PNES are also commonly associated with other dissociative and functional neurological symptoms.
According to a 2006 review, while there is evidence suggesting a link between child sexual abuse and PNES, limitations in research design make it "premature to draw any definitive conclusions regarding a relationship".
Chronic pain Patients with PNES are more likely to experience chronic pain than patients with epilepsy, with a gender predisposition towards women. Persistent pain can be disabling and stressful, which may reinforce harmful coping strategies and exacerbate PNES. There is some speculation that opioid system could be involved in the pathophysiology of PNES and dissociation. The body's internal (or endogenous) opioid system plays a role in its response to chronic stress or trauma by increasing release of opioids. Additionally, up to one-third of patients with PNES take opioid pain medication.
Traumatic brain injury (TBI) A history of traumatic brain injury (TBI; typically mild) ranging from 16–83% has been reported in patients with PNES. TBI can have prolonged neuropsychiatric sequalae, mediated by the patients' personal experience of their injury which is usually in a stressful setting, which can create and potentiate harmful stress responses. Subtle changes in brain structure from mild TBI, which may not be visible on imaging, such as diffuse axonal injury, may disrupt multiple connecting networks in the brain (global connectivity). These factors are thought to play a role in dissociation and, therefore, may contribute to the development of PNES.
Other comorbidities Individuals with PNES have been shown to have an elevated prevalence of other conditions, including fibromyalgia, myalgic encephalomyelitis/chronic fatigue syndrome, migraine, asthma, or irritable bowel syndrome. Other reported complaints include sleep problems (e.g., sleep-disordered breathing, periodic limb movement disorder, and lower sleep quality) and cognitive challenges (e.g., forgetfulness and concentration difficulties). Patients often have higher use of medications for pain (including opioids), high blood pressure, respiratory symptoms, sleep, and acid reflux.
Mechanisms
Neurobiological mechanisms of PNES are not well understood. However, functional neuroimaging has implicated certain structures. Because PNES is considered a disorder of brain function, there has been a growing body of research to investigate functional brain changes in these patients. According to a 2024 literature review of patients with PNES who underwent brain imaging, three neuroanatomical locations were recurrently found to have functional (rather than structural) abnormalities as detailed in the table below. More research needs to be completed to further evaluate the pathophysiology of PNES.
Structure Function AmygdalaLearning and emotional balance Orbitofrontal cortexExecutive function and emotional regulation Anterior cingulate cortexDecision making, emotional regulation, visuospatial orientation
Diagnosis PNES are often difficult to distinguish from epileptic seizures based on clinical observation alone. The gold standard for diagnosis is video-EEG monitoring, which records both the clinical event and corresponding brain activity. In PNES, seizure-like behavior occurs in the absence of epileptiform activity on the EEG. While routine EEGs may be performed during initial evaluation, they are often normal or inconclusive in individuals with PNES and cannot confirm the diagnosis. Certain clinical features may raise suspicion of PNES, but none are definitive, and many overlap with epileptic seizures.
In the DSM-5, psychogenic non-epileptic seizures are classified under functional neurological symptom disorder (conversion disorder). The diagnosis is based on the presence of neurological symptoms that are incompatible with known neurological conditions and not better explained by another disorder, and cause significant distress or impairment.
Neuroimaging Imaging studies of patients with PNES typically do not reveal any structural disease process that explains their symptoms. While not required to make a diagnosis, brain imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) are often ordered.
Differential diagnosis An important step in differential diagnosis is to exclude epilepsy, along with other organic causes of non-epileptic seizures, including syncope, migraine, vertigo, anoxia, hypoglycemia, and stroke. However, 10–30% of people with PNES also have comorbid epilepsy. Frontal lobe seizures can be mistaken for PNES, though these tend to have shorter duration, stereotyped patterns of movements, and occurrence during sleep. Psychiatric conditions can also produce symptoms resembling PNES. Distinguishing these requires careful assessment of semiology, clinical context, and psychiatric history.
Factitious disorder and malingering may be considered in rare cases where there is evidence of intentional symptom production. These are distinct entities with different motivations; in the vast majority of cases, PNES occur involuntarily and without conscious intent.
Complications
Patients with PNES have a lower quality of life on average than patients with epilepsy, with contributing factors including somatic symptoms, psychiatric comorbidities, and cognitive complaints. Stigma and social isolation are common in patients with PNES. Many lose the ability to work and in most jurisdictions are not able to drive. This can be exacerbated by a delay in diagnosis or misdiagnosis. Healthcare providers have been found to have negative biases towards patients, which can further exacerbate these problems. Patients with PNES have been found to be more likely on government assistance and to earn less after onset of the condition.