Psychogenic Nonepileptic Seizures

Psychogenic nonepileptic seizures, also called functional or dissociative seizures, are episodes of altered movement, sensation or awareness that resemble epileptic seizures but are not caused by abnormal epileptic discharges. They are a functional neurological disorder with real symptoms and need positive diagnosis and psychological treatment.

About 20 to 30% of patients referred to epilepsy centres with apparent drug resistant seizures have functional seizures. The incidence is about 1.4 to 4.9 in every 100,000 people each year, and 70 to 80% of patients are women, with onset commonly between 15 and 35 years. Epilepsy coexists in about 10 to 30%.

Risk factors. Childhood adversity and trauma, anxiety and depression, personality and dissociative disorders, chronic pain, head injury and functional somatic symptoms.

Prognosis. Seizure freedom occurs in about one third to one half after treatment, and the outcome is better with early diagnosis, short duration, and acceptance of the diagnosis. Many keep other symptoms.

Pathophysiology.

A biopsychosocial model involves altered attention and motor control, heightened threat processing, dissociation and learned automatic responses, rather than structural brain damage.

Predisposing, precipitating and perpetuating factors interact, with a disrupted sense of agency in seizure behaviour.

• Events lasting over 2 minutes, with a fluctuating course, waxing and waning movements, and asynchronous limb movements.
• Eyes closed during the event and resistance to eye opening, side-to-side head movements, pelvic thrusting, ictal weeping and memory of the event.
• Gradual onset and no postictal confusion, although the person may be exhausted.
• Occurring only in company, and often after emotional triggers; injuries are less common but do occur.
• Features that can occur in either seizure type must not be used alone to decide the diagnosis.

Red flags.

• Self-harm, suicidal thoughts or severe depression.
• Coexisting epilepsy, which needs its own treatment.
• Prolonged events treated as status epilepticus, with a risk of intubation and sedation harm.

• Video EEG capturing a typical event, with no ictal epileptiform change and a normal postictal EEG, is the reference test.
• Home or witness video and semiology review when video EEG is not available, by an experienced clinician.
• Serum prolactin and creatine kinase are unreliable and are not used for diagnosis.
• Assessment of psychiatric and psychological comorbidity, trauma history and functional symptoms.
• Review of previous investigations and past antiseizure drug use.

Differential diagnosis. Epileptic seizures (especially frontal lobe epilepsy), syncope, convulsive syncope, parasomnias, panic attacks, hyperventilation, movement disorders and cardiac arrhythmia.

• Explain the diagnosis clearly and positively, state that the events are real and common, and that treatment can help; give written information.
• Psychological treatment is central: cognitive behavioural therapy adapted for functional seizures, with specialist neuropsychiatry or psychology input, and physiotherapy when other functional symptoms occur.
• Stop antiseizure drugs that were started for presumed epilepsy, by gradual withdrawal, unless coexisting epilepsy is confirmed.
• Avoid benzodiazepines, intubation and intensive care escalation for prolonged functional events unless there is clinical or EEG evidence of epileptic status.
• Treat comorbid depression and anxiety: sertraline 50 mg orally once daily, increased by 50 mg every 1 to 2 weeks as needed to 100 to 200 mg daily. Maximum 200 mg daily. Continue for at least 6 to 12 months after remission. Monitor mood and suicidal thoughts (especially under 25 years), sodium, bleeding and serotonin toxicity features. Reduce the dose (or use alternate days) in hepatic impairment; no renal adjustment; avoid with monoamine oxidase inhibitors; acceptable in pregnancy and breastfeeding with specialist advice.
• Seizure action plan for family and emergency staff, noting that most events do not need emergency care.
• Occupational and social rehabilitation; address dependency on health services.

Monitoring. Review at 4 to 6 weeks, then every 3 months; track event frequency, mood and functioning.

Referral and escalation. Neurology and neuropsychiatry or clinical psychology for all patients; urgent psychiatric review for self-harm risk.

Special groups. Children and adolescents: family therapy and school input. Pregnancy: stop unnecessary antiseizure drugs, and manage mood with specialist advice.