Conversion Disorder (Functional Neurological Symptom Disorder – FND)

Conversion Disorder, now more commonly referred to as Functional Neurological Symptom Disorder (FND) in the *DSM-5*, is a condition where patients experience neurological symptoms (e.g., weakness, seizures, paralysis) without an identifiable organic cause. These symptoms are involuntary and often linked to psychological stress or trauma.

Key Features

  • “Neurological” symptoms with no medical explanation (e.g., MRI/EEG normal).
  • Temporal association with stress/trauma (though not always consciously recognized).
  • Symptoms are real and distressing (not faked or intentional).
  • Commonly affects movement or senses:
    • Weakness/paralysis (e.g., “glove anesthesia”).
    • Non-epileptic seizures (“pseudo-seizures”).
    • Tremors, gait abnormalities, blindness, or speech difficulties.

Diagnostic Criteria (DSM-5)

  1. At least one symptom of altered voluntary motor or sensory function.
  2. Clinical findings show incompatibility between symptoms and recognized neurological conditions.
  3. Symptoms cause significant distress or impairment.
  4. Not better explained by another medical/psychiatric disorder.

Note:

  • Psychological stressors may not be immediately evident (no longer required for diagnosis).
  • “La belle indifférence” (apparent lack of concern about symptoms) is not a reliable sign.

Causes & Risk Factors

Psychological Factors

  • Past trauma (physical/sexual abuse, PTSD).
  • Stressful life events (loss, divorce, chronic illness).
  • Anxiety, depression, or somatic symptom disorder.

Neurobiological Factors

  • Abnormal brain connectivity (between emotion-processing and motor-control regions).
  • Dysregulation of the limbic system and prefrontal cortex.

Other Risk Factors

  • Female sex (2-3x more common in women).
  • History of childhood neglect or chronic illness.

Differential Diagnosis (Rule Out First!)

ConditionKey Differences
Multiple SclerosisMRI lesions, progressive course.
EpilepsyAbnormal EEG during seizures.
StrokeSudden onset, imaging abnormalities.
Myasthenia GravisFatigable weakness, positive antibody tests.
Factitious Disorder/MalingeringIntentional symptom production for secondary gain.

Treatment Approaches

1. Psychotherapy (First-Line)

  • Cognitive Behavioral Therapy (CBT) – Addresses maladaptive thoughts and stress responses.
  • Trauma Therapy (EMDR, DBT) – If linked to past trauma.
  • Physical/Occupational Therapy – For motor symptoms (retraining neural pathways).

2. Medication (Limited Role)

  • SSRIs/SNRIs (if comorbid anxiety/depression).
  • Short-term benzodiazepines (for acute anxiety, but avoid long-term use).

3. Explanation & Reassurance

  • Clear, non-judgmental communication:
    • “Your symptoms are real, but they’re due to a misfire in brain signaling, not permanent damage.”
  • Avoid dismissive language (e.g., “It’s all in your head”).

4. Multidisciplinary Care

  • Neurologist + Psychiatrist + Physical Therapist collaboration.

Prognosis

  • ~50% improve with early intervention.
  • Better outcomes if:
    • Short symptom duration.
    • No comorbid psychiatric disorders.
    • Strong therapeutic alliance.
  • Poorer outcomes if:
    • Long-standing symptoms.
    • Secondary gain (e.g., disability benefits).

When to Refer to a Specialist

  • Neurologist (to rule out organic causes).
  • Psychiatrist/Psychologist (for CBT or trauma therapy).
  • Physical therapist (for functional rehabilitation).