Dissociation and Focal Impaired-Awareness Seizures — Why They Can Be Confused

Feeling detached from yourself or the world can occur in more than one condition. Dissociation can appear in functional neurological disorders, trauma-related conditions, panic and other psychiatric states, but dissociative-like experiences can also occur as part of focal epileptic seizures.

What does dissociation mean?

Dissociation describes disruption in normally integrated experiences such as consciousness, memory, identity, perception or the sense of being connected to one’s body or surroundings. Examples include depersonalisation, derealisation and a “dream-like” state.

Dissociative-like symptoms in epilepsy

Temporal-lobe seizures can produce déjà vu, jamais vu, derealisation, depersonalisation and other altered experiences of familiarity or self. These symptoms can be brief and highly stereotyped.

Focal impaired-awareness seizures

In focal impaired-awareness seizures, awareness is impaired at some point during the seizure. The person may stare, stop responding normally, perform automatisms, speak abnormally or later have incomplete memory for the event.

Functional or dissociative seizures

Functional seizures are real involuntary events but are not caused by the abnormal hypersynchronous electrical activity that defines epileptic seizures. They can involve altered awareness, movement, sensory experiences and dissociation.

No single symptom reliably separates them

A 2026 systematic review found that subjective symptoms in functional/dissociative seizures are highly variable. Some dissociation between awareness and responsiveness may have diagnostic value, but symptom descriptions need detailed context, onset, spread, duration and quality.

Coexistence matters

Epilepsy and functional seizures can occur in the same person. Dissociative symptoms can also occur interictally in people with epilepsy. A binary assumption that symptoms must be “neurological or psychological” can therefore be misleading.

Video-EEG is often central

When events remain diagnostically uncertain, capturing a typical episode with video-EEG is often the most useful test because behaviour and EEG are recorded together. Even then, interpretation requires experienced clinicians because some focal seizures can be difficult to detect on scalp EEG.

Useful observations

  • precise onset and offset;
  • whether responsiveness is impaired and in what way;
  • whether movements are stereotyped;
  • whether there are automatisms;
  • memory before, during and after the event;
  • the presence of déjà vu, olfactory symptoms or a rising epigastric sensation;
  • event duration and recovery;
  • triggers and context.

Related reading

Sources and further reading

Evidence checked: September 2026.

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