Psychiatry · Year 3 · from Psychiatry

Case 2: Conversion Disorder (Functional Neurological Symptom Disorder)

Patient Demographics

  • Age: 28 years old
  • Sex: Female
  • Occupation: Elementary school teacher

Chief Complaint

"I can't walk. My legs just stopped working."

History of Present Illness

The patient is a 28-year-old woman who presents with acute onset of bilateral leg weakness that began 5 days ago. She reports waking up and being unable to stand. She denies any preceding injury, illness, or trauma. Neurological evaluation in the ED including CT and MRI of the brain and spine was unremarkable. Nerve conduction studies and EMG were normal. She was admitted for further workup, which has remained negative.

On further psychiatric history, the patient reveals that she had a significant argument with her fiance 6 days ago (the night before symptom onset) during which he disclosed he had been unfaithful. The wedding was scheduled for 3 weeks from now. She describes feeling "paralyzed" by the news and unable to decide what to do. She has no conscious awareness of a connection between the argument and her symptoms. She appears remarkably calm when discussing her inability to walk ("la belle indifference") but becomes tearful when discussing the relationship conflict.

Neurological Examination

Motor Examination:

  • Bilateral leg weakness (0/5 strength on initial testing)
  • Hoover's sign positive: Involuntary hip extension noted in the "weak" leg when testing hip flexion of the contralateral leg
  • Give-way weakness: Initial resistance followed by sudden collapse
  • Inconsistency: Patient observed to move legs when repositioning in bed when she believes she is not being observed

Sensory Examination:

  • Reports complete numbness below the waist
  • Sensory loss splits exactly at midline (non-anatomic)
  • Vibration sense "absent" at iliac crest but present at sternum (anatomically implausible)

Reflexes: Normal and symmetric throughout

Other:

  • Gait: Unable to attempt
  • Coordination: Unable to assess in legs
  • No bowel or bladder dysfunction

Mental Status Examination

Appearance: Young woman in hospital gown, lying flat, legs motionless

Behavior: Cooperative, calm demeanor despite severe symptoms

Speech: Normal rate, rhythm, and volume

Mood: "Okay, I guess"

Affect: Incongruent with situation - calm and occasionally smiling despite paralysis ("la belle indifference")

Thought Process: Linear, goal-directed

Thought Content:

  • Focus on physical symptoms
  • Distress about relationship conflict when explored
  • No suicidal ideation
  • No psychotic symptoms

Insight: Limited regarding connection between psychological stressors and physical symptoms

Judgment: Fair - accepting of evaluation and treatment

Diagnosis

Conversion Disorder (Functional Neurological Symptom Disorder) with Weakness (F44.4)

DSM-5 Criteria Met: A. One or more symptoms of altered voluntary motor function (bilateral leg weakness) B. Clinical findings provide evidence of incompatibility between symptom and recognized neurological conditions:

  • Positive Hoover's sign
  • Give-way weakness
  • Inconsistency between examination and observed function
  • Non-anatomic sensory findings

C. Symptom not better explained by another medical or mental disorder D. Symptom causes clinically significant distress or impairment

Note: Diagnosis made based on positive clinical findings of incompatibility, not simply absence of medical findings

Treatment Plan

Communication of Diagnosis:

  • Explain that symptoms are real and not "faked"
  • Use positive language: "The good news is your nervous system is intact. The problem is a software issue, not a hardware issue"
  • Explain that the brain is having difficulty sending the correct signals to the legs
  • Emphasize that this is a recognized, treatable condition

Physical Therapy:

  • Core treatment for motor conversion symptoms
  • Graduated exercises with positive reinforcement
  • Focus on function rather than impairment
  • Avoid reinforcing sick role

Psychotherapy:

  • Explore relationship stressors and emotional processing
  • Address decision-making regarding wedding
  • Supportive therapy initially, transitioning to insight-oriented work

Pharmacotherapy:

  • Consider SSRI if comorbid depression or anxiety identified
  • Currently not indicated as primary treatment

Prognosis Discussion:

  • Generally favorable with early intervention
  • Explain that recovery typically occurs over days to weeks with appropriate treatment
  • Avoid suggesting symptoms are permanent

Follow-up:

  • Daily physical therapy
  • Psychiatry follow-up in 1 week
  • Discharge planning when ambulatory

All cases for this lecture as Markdown