Case 32: A woman who cannot move her right arm and leg after a quarrel

01The case

A 34-year-old woman is brought to the psychiatric emergency service with a problem that began suddenly two days ago, after a fight with her husband. Her relatives describe a drooping right corner of the mouth, like a facial nerve palsy, and numbness and inability to move her right arm and right leg. A neurological examination beforehand found nothing abnormal. During the visit she seems friendly and untroubled by her symptoms, while her relatives look very worried.

02Summary

Diagnosis

Conversion disorder, one of the dissociative (conversion) disorders of ICD-10; in ICD-11 dissociative neurological symptom disorder, in DSM-5 functional neurological symptom disorder.

What points to it

• Symptoms that look neurological (weakness, numbness, a facial droop) without neurological disease to explain them.
• Sudden onset straight after a stressful event, the quarrel.
• Positive signs of a functional disorder are what confirm it: Hoover's sign (the "paralysed" leg pushes down when she lifts the other leg against resistance), give-way weakness, numbness that splits exactly at the midline. A functional facial "droop" is often overactivity of the muscles of the lip or jaw, not weakness.

What else it could be

Sudden weakness of one side of the face and body must be treated as a stroke until proven otherwise: at 34 this is less likely but possible, so brain imaging is needed even after a normal examination. Also multiple sclerosis, migraine with aura, a seizure with weakness afterwards, hypoglycaemia. In factitious disorder and malingering the symptoms are produced on purpose; in conversion they are not.

Management

• Exclude organic disease together with the neurologists, without endless tests.
• Explain the diagnosis as positive, common and likely to get better: a problem of how the nervous system works, not of its structure. Showing her Hoover's sign can help.
• Physiotherapy aimed at normal movement, and CBT or supportive psychotherapy; avoid aids such as crutches that keep the disability going.
• Work with the couple on the conflict behind it.
• Treat anxiety or depression if present, with an antidepressant if needed; sedatives are not a treatment for the weakness.

Outlook

Fairly good in the short term. Symptoms of short duration and sudden onset often get better within days or weeks, but in many people functional symptoms come back or become chronic, especially if nothing changes at home.