Not every seizure-like event in the ED is epilepsy. Psychogenic non-epileptic seizures (PNES) are common seizure mimics that rookies often misdiagnose. Giving unnecessary anti-seizure meds or intubating these patients can cause harm. Recognizing PNES at the bedside is a key skill — though final diagnosis always requires neurology follow-up.
What Are PNES?
- Paroxysmal events resembling epileptic seizures but without abnormal cortical electrical activity.
- Classified as a functional neurological disorder (conversion disorder).
- Often associated with psychiatric comorbidities: depression, PTSD, anxiety, personality disorders.
Why It Matters in the ED
- PNES account for 20–30% of patients referred to epilepsy centers.
- Misdiagnosis → years of unnecessary AEDs, ICU stays, intubations.
- Correct recognition avoids harm and unnecessary interventions.
Key Bedside Features Suggesting PNES
During the Event
- Asynchronous movements (arms/legs moving out of phase).
- Side-to-side head shaking (rare in epilepsy).
- Eyes tightly shut with resistance to opening.
- Pelvic thrusting movements.
- Long duration (>2–3 minutes) without postictal phase.
- Variable pattern — stops/starts, changes movement type mid-event.
- Vocalizations (crying, screaming) during episode.
After the Event
- Rapid recovery without postictal confusion.
- No tongue bite (especially lateral) or incontinence.
- Minimal or absent postictal fatigue compared to epilepsy.
Tools to Help
- EEG: Gold standard for diagnosis (normal activity during event).
- Video-EEG monitoring confirms in specialized centers.
- Serum prolactin: Sometimes elevated after generalized epileptic seizures, but normal in PNES — not reliable in ED.
ED Priorities
- Do not assume epilepsy.
- Rule out dangerous mimics: syncope, hypoglycemia, toxic/metabolic causes.
- If true status epilepticus can’t be excluded, treat as seizure first — safety comes before certainty.
- Once stabilized, gently explain that event was “non-epileptic,” avoid stigmatizing language.
- Arrange neurology + psychiatry follow-up.
Common Rookie Mistakes
- Giving multiple doses of benzos in PNES — leads to respiratory depression, unnecessary intubation.
- Calling events “faking” — PNES are involuntary, not intentional.
- Forgetting to consider PNES in “status” patients with preserved vitals and atypical movements.
- Relying solely on serum prolactin — not reliable enough to rule in/out.
Rookie Pearls
- Eyes closed + asynchronous movements = think PNES.
- If uncertain, treat first episode as seizure — harm of missing true seizure > risk of 1–2 doses benzo.
- PNES often triggered in stressful environments (crowded ED, painful procedures).
- Early psych referral improves long-term outcomes.
Take-Home Message
Psychogenic non-epileptic seizures are common seizure mimics in the ED. For rookies:
- Recognize atypical features (eyes closed, asynchronous movements, long duration, rapid recovery).
- Rule out true seizures and dangerous mimics.
- Avoid excessive AEDs or intubation unless airway truly compromised.
- Arrange neurology + psych follow-up — these patients need care, not dismissal.
Remember: PNES are real, disabling events — but they require recognition and the right kind of treatment.
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