Definition and Diagnosis
Conversion disorder, termed functional neurological symptom disorder in DSM-5-TR, involves one or more symptoms of altered voluntary motor or sensory function (such as weakness, abnormal movements, or non-epileptic seizures) that are incompatible with recognized neurological or medical conditions on clinical examination.
Epidemiology
Conversion disorder is relatively uncommon in the general population but is seen more frequently in neurology clinics, with incidence estimated at several cases per 100,000 per year, and it is more common in women.
Risk Factors
Risk factors include a history of psychological stress or trauma, co-occurring dissociative or other psychiatric conditions, a prior neurological condition, and, in some cases, exposure to someone else's illness that may serve as a symptom model.
Symptoms and Subtypes
Presentations can include limb weakness or paralysis, abnormal gait, tremor, non-epileptic (psychogenic) seizures, or sensory disturbances such as numbness or visual loss, with clinical signs on examination that are inconsistent with recognized neurological disease patterns.
Diagnosis
Diagnosis is made by a clinician (often in conjunction with neurology) based on positive clinical findings demonstrating incompatibility with recognized neurological disease, rather than solely by exclusion, alongside consideration of associated psychological factors.
Treatment
Treatment is multidisciplinary, involving clear, non-judgmental communication of the diagnosis, physiotherapy for motor symptoms, and psychotherapy (such as CBT) addressing associated stress or psychological factors; collaboration between neurology and psychiatry improves engagement and outcomes.
Prognosis
Prognosis varies; symptoms of shorter duration, clear precipitating stressors, and early diagnosis and multidisciplinary treatment are associated with better outcomes, while chronic presentations can be more resistant to treatment.
Reference
Sadock, B. J., Sadock, V. A., & Ruiz, P. Kaplan & Sadock's Synopsis of Psychiatry (11th ed.); New Oxford Textbook of Psychiatry (2nd ed.).