Synopsis
Diagnose functional or dissociative seizures from positive clinical evidence, protect patients from iatrogenic emergency treatment and stigma, identify coexisting epilepsy, and communicate a credible rehabilitation-focused treatment plan.
- Psychogenic non-epileptic seizures are increasingly called functional or dissociative seizures because the events are genuine, involuntary manifestations of functional neurological disorder rather than deliberate behaviour.
- Make the diagnosis from positive semiological features and specialist expertise, ideally capturing a typical habitual event on video-EEG without an epileptic ictal correlate when scalp EEG should detect one.
- Prolonged fluctuating episodes, asynchronous limb movements, tightly closed eyes, variable responsiveness and recall can support functional seizures, but no single sign is diagnostic and frontal epilepsy can be unusual.
- A normal routine interictal EEG does not prove functional seizures because many people with epilepsy have normal recordings between events.
- Functional seizures and epilepsy can coexist; establish whether every reported event type has been characterised before withdrawing antiseizure medicine or altering emergency plans.
- During a recognised typical event, keep the environment calm, protect from injury, avoid restraint and painful stimuli, and do not escalate repeated benzodiazepines when breathing and physiology are stable.
- Explain the diagnosis directly: the episodes are real, common and potentially treatable, arise from altered nervous-system functioning, and are not fabricated or equivalent to structural brain damage.
- Treatment begins with diagnostic understanding and may include seizure-warning and grounding strategies, FND-informed psychological therapy, occupational rehabilitation and treatment of relevant mood, trauma, sleep or pain disorders.
- Antiseizure medicines do not treat functional seizures themselves; taper unnecessary therapy under neurological supervision after coexisting epilepsy has been sufficiently excluded.
- Dissociative seizures are notifiable to DVLA and have their own current licensing standards, so driving advice remains necessary even after epilepsy is removed from the diagnosis.
Key red flags
A separate stereotyped brief event with lateralised onset, injury, postictal confusion or epileptiform evidence should be characterised independently rather than folded into the functional diagnosis.
Repeated benzodiazepines, intubation or critical-care admission for prolonged stable events despite prior functional diagnosis signals the need for an accessible, specific emergency plan and staff education.
Investigation priorities
Identify positive functional features and determine whether more than one event phenotype exists.
Management branches
A seizure-like event occurs in someone with suspected or documented functional seizures.
- 1. Assess airway, breathing, circulation, glucose, injury and pregnancy or new-neurology context, and compare the event with the documented habitual phenotype.
- 2. Remove hazards, cushion the head, maintain a calm low-stimulation environment, avoid restraint and painful stimulation, and observe breathing and recovery.
- 3. If the event is typical and physiology stable, avoid repeated benzodiazepines and intubation; use the agreed grounding or recovery plan when the person is receptive.
- 4. Escalate normally for a new pattern, significant injury, hypoxia, metabolic abnormality, suspected epileptic status or failure to recover in the expected way.
Key medicines
No antiseizure medicine for functional seizures aloneThere is no therapeutic antiseizure dose for functional seizures; when epilepsy has been sufficiently excluded, an epilepsy specialist should withdraw unnecessary medication gradually, usually one agent at a time on a medicine-specific schedule.Never stop abruptly or taper before all event phenotypes and the original epilepsy evidence are reviewed. Some people have both conditions, and benzodiazepine or barbiturate withdrawal requires a particularly slow specialist schedule.
Medication for a defined comorbidityTreat depression, anxiety, migraine, pain or sleep disorder using its own evidence-based regimen and careful titration; no antidepressant or analgesic should be presented as a direct cure for functional seizures.Agree a named target and monitor response. Avoid sedative polypharmacy, opioid escalation and adverse interactions, and do not imply that prescribing proves a purely psychiatric cause.