Educational Disclaimer: This case study is for educational and informational purposes only. It does not constitute medical advice, clinical guidance, or a substitute for professional psychiatric evaluation. All diagnostic criteria referenced are from the DSM-5-TR (APA, 2022). Clinicians should rely on their professional training, direct patient assessment, and current evidence-based guidelines when making diagnostic and treatment decisions.

Clinical Vignette

Patient: "Ms. U," 24-year-old nursing student, referred after video-EEG monitoring confirmed her seizure-like episodes show no epileptiform activity.

Chief Concern: "I've been having seizures for 2 years. My neurologist says they're not 'real' seizures but they feel completely real to me. I shake, I fall, I sometimes lose consciousness. How can they not be real?"

History of Present Illness: Ms. U has experienced seizure-like episodes for 2 years, occurring 2-4 times monthly. Episodes involve bilateral limb shaking, eyes closed or fluttering, unresponsiveness lasting 2-10 minutes, and sometimes urinary incontinence. She has been prescribed two antiepileptic medications without improvement. Video-EEG monitoring during a typical episode showed: bilateral asynchronous limb movements (non-rhythmic), eyes held tightly closed (forced eye closure), retained upgoing plantar response, and NO epileptiform activity on EEG during the clinical event. Between episodes, she reports chronic fatigue, intermittent limb weakness, and 'foggy thinking.' Her episodes began 1 month after a sexual assault at age 22 that she has never discussed with a clinician. She disclosed this only when specifically asked about traumatic events in the context of the current evaluation.

Medical History: No epilepsy risk factors. Normal brain MRI. Two antiepileptic medication trials (levetiracetam, lamotrigine) without benefit.

Mental Status Exam: Cooperative, earnest. Appears fatigued. Speech normal. Mood 'frustrated.' Affect somewhat flat. No psychotic symptoms. Reports depressed mood and anxiety about episodes. Endorses avoidance of situations where she might have an episode (public places, alone). When asked about the assault, became tearful and visibly distressed. Insight developing.

Step 1: Conversion Disorder (FND) DSM-5-TR Criteria

Criterion A: One or more symptoms of altered voluntary motor or sensory function.

Seizure-like episodes (altered motor function). Limb weakness (motor symptom). These are genuine symptoms experienced by the patient. MET.

Criterion B: Clinical findings provide evidence of incompatibility between the symptom and recognized neurological or medical conditions.

Video-EEG: no epileptiform activity during clinical seizure. Positive signs of functional (non-epileptic) seizures: asynchronous movements, forced eye closure (epileptic seizures typically have eyes OPEN), non-rhythmic movements. These are POSITIVE findings of functional etiology, not merely 'absence of neurological disease.' MET — POSITIVE CLINICAL SIGNS.

Criterion C: Not better explained by another medical or mental disorder.

Epilepsy excluded by video-EEG. Not factitious (not deliberately producing symptoms). Not malingering (no secondary gain identified; she is distressed by episodes). MET.

Criterion D: Causes clinically significant distress or impairment.

2-4 episodes monthly. Avoidance behavior. Impaired nursing education. Distress about the episodes. MET.

Step 2: Positive Signs of Functional (Non-Epileptic) Seizures

DSM-5-TR emphasizes that FND diagnosis should be based on POSITIVE clinical findings of incompatibility, not merely absence of disease:

Clinical Sign PNES (Functional) Epileptic Seizure This Patient
Eye position Eyes CLOSED (forced eye closure) Eyes typically OPEN Eyes closed during episodes
Movement pattern Asynchronous, waxing/waning, non-rhythmic Synchronous, rhythmic, stereotyped Asynchronous, non-rhythmic
Duration Often >2 minutes Typically 1-2 minutes (tonic-clonic) 2-10 minutes
EEG during event Normal or movement artifact only Epileptiform discharges No epileptiform activity
Response to AED No improvement Expected improvement Failed two AEDs
Post-ictal state Rapid recovery often Gradual, confusion common Variable

Diagnostic Paradigm

The diagnosis of PNES is based on POSITIVE clinical evidence (forced eye closure, asynchronous movements, normal ictal EEG), not on the absence of epilepsy alone. This distinction is critical for communicating the diagnosis to the patient: the episodes are 'diagnosed' (not 'not epilepsy').

Diagnostic Formulation

Diagnostic Conclusion

Conversion Disorder (Functional Neurological Symptom Disorder), with Attacks or Seizures (F44.5): All 4 DSM-5-TR criteria met. Positive clinical signs of functional non-epileptic seizures confirmed by video-EEG. Two-year duration. Episode frequency 2-4/month. Psychosocial context: onset 1 month after sexual assault (undisclosed). Treatment: (1) Deliver diagnosis using positive language ('your brain is producing real seizures through a functional mechanism, not epilepsy'). (2) Taper antiepileptic medications. (3) CBT for functional seizures (seizure management, trigger identification). (4) Trauma-focused therapy for undisclosed assault. (5) Physical rehabilitation for weakness.

Teaching Points

  • DSM-5-TR renamed and reconceptualized this disorder to emphasize POSITIVE diagnostic criteria (Criterion B: clinical findings of incompatibility) rather than the absence of medical disease. This is a 'rule-in' diagnosis, not a 'rule-out' diagnosis. The positive signs (forced eye closure, asynchronous movements) are reliable clinical indicators.
  • How the diagnosis is communicated to the patient is itself a therapeutic intervention. Use positive, non-stigmatizing language: 'Your seizures are real — your brain is producing them through a functional mechanism different from epilepsy. This is a recognized, treatable condition.' Avoid: 'Your seizures are fake/not real/psychosomatic/in your head.'
  • Antiepileptic medications should be tapered and discontinued once PNES is diagnosed. Continued AED use exposes the patient to side effects without benefit and communicates that the clinician does not believe the functional diagnosis.
  • Functional neurological disorders are common in neurological practice. PNES accounts for a significant proportion of referrals to epilepsy monitoring units. Early accurate diagnosis prevents years of unnecessary AED exposure and repeated emergency department visits.
  • Trauma history is present in a significant proportion of patients with functional neurological disorders, but is NOT required for the diagnosis. DSM-5-TR explicitly removed the requirement for a psychological stressor. The diagnosis is made on positive clinical signs, irrespective of whether a stressor is identified.