Epidemiology and Etiology
- Estimated prevalence varies, with the highest prevalence found in neurology clinics.
- More common in women and patients of low socioeconomic status
- Manifests in adolescence and early adulthood
- More prevalent in patients with neurologic or psychiatric comorbidities
- Exact etiology is unknown.
- Thought to be a combination of psychodynamic, developmental, biological, and social pathology
- Stressful life events have been shown to be potential triggers for the physical symptoms.
- There is evidence for impaired communication between the amygdala and supplementary motor area, causing excessive cortical arousal.
Conversion disorder presents with neurologic symptoms that are inconsistent with structural disease.
- Patients may present with sensory complaints that do not map to known nerve distributions (e.g., weakness/paresthesia in the entire leg).
- Patients showing non-epileptiform seizures may have abnormal features (eyes closed tightly) and should be evaluated with video EEG.
Common motor symptoms:
- Non-epileptic seizures (psychogenic seizures)
- Tremor (psychogenic tremor)
- Impaired gait
Common sensory symptoms:
- Vision impairment (blindness, decreased visual field)
- Hearing impairment
- Associated with so-called la belle indifference: Patients appear to be inappropriately unconcerned with their symptoms given their level of disability.
- History and physical exam should begin from the patient in the waiting room until the patient leaves the office, as inconsistencies are likely to be found.
- Baseline investigations may include:
- Basic metabolic panel
- Liver function tests
- Thyroid panel
- Toxicology screen
- Imaging may be required.
DSM-V diagnostic criteria
- At least 1 impairment in voluntary motor or sensory function
- Clinical findings show evidence of incongruence between the symptoms and recognized exam findings.
- Symptoms cannot be better explained by another disorder.
- Symptoms cause clinically significant distress or impairment in social, occupational, or other areas of function.
The following 2 tests may help differentiate conversion disorder from organic disease, if the respective neurological deficits are present.
- Hoover’s sign:
- Diagnostic test to differentiate organic from non-organic leg paresis
- Patient must be supine; examiner cups both hands under the patient’s heels.
- Patient is instructed to flex the hip of the non-paretic leg.
- Examiner should feel the contralateral heel press down into their palm.
- When the patient is asked to flex the hip of the paretic leg, the examiner should similarly feel the contralateral heel press down into their palm.
- Positive: failure of the contralateral heel to depress → hip girdle is not being activated to lift the paretic leg → suggestive of conversion disorder
- Drop arm test:
- While patient is lying down, raise the impaired arm above the patient and release.
- In patients with conversion disorder, the arm will not hit the face.
|Symptom||Physical exam maneuver||Characteristic findings for conversion disorder|
|Tremor||Distraction||Tremor intensity decreases.|
|Impaired gait||Chair test||Gait is impaired but patient is able to rock chair back and forth while sitting down.|
|Anesthesia||Dermatome testing||Testing of loss of sensation does not follow dermatome patterns.|
|Blindness||Fingertip touching test|
|Deafness||Startle test||Patient becomes startled in response to unexpected noise.|
|Symptoms||Excessive worry||Exam findings|
|Somatic symptom disorder||+||+||–|
|Illness anxiety disorder||–||+||–|
Management and Prognosis
- Clinicians must assure patients that their symptoms are real, but do not represent irreversible damage.
- Establishing good rapport as well as working in a multidisciplinary team is important.
- Treatment of choice is psychotherapy, usually CBT.
- Physical therapy for evaluation and treatment of underlying distress.
- Utilize pharmacotherapy when there are other comorbid psychiatric illnesses such as depression or anxiety.
- Relatively poor with low response to current treatment modalities
- Higher patient confidence in physician as well as shorter duration of symptoms are associated with better outcome.
- Myasthenia gravis (MG): an autoimmune neuromuscular disorder caused by dysfunction of acetylcholine receptors at the neuromuscular junction. The condition presents with fatigue, ptosis, diplopia, dysphagia, respiratory difficulties, and progressive weakness in the limbs leading to difficulty in movement. Diagnosis is established based on clinical presentation as well as detection of antibodies and electrophysiologic studies, which are negative in CD.
- Somatic symptom disorder (SSD): a condition in which patients present with 1 or multiple somatic complaints and excessive thoughts and concern about the severity of their symptoms. Management is with CBT. Somatic symptom disorder is a diagnosis of exclusion as there are no exam findings, unlike in CD.
- Illness anxiety disorder: a condition characterized by prolonged and exaggerated concern about one’s health and possible illness. Patients fear or are convinced that they have a disease and interpret minor or normal bodily symptoms as signs of serious medical conditions. Management is with CBT. Those with CD do not exhibit the excessive worry found in illness anxiety disorder.
- Ali, S, Jabeen, S, Pate, RJ, Shahid, M, Chinala, S, Nathani, M, & Shah, R. (2015). Conversion Disorder- Mind versus Body: A Review. Innovations in clinical neuroscience, 12(5-6), 27–33.
- American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author
- Mehndiratta, MM, Kumar, M, Garg, H, & Pandey, S. (2014). Hoover’s sign: Clinical relevance in Neurology [Abstract]. Journal of Postgraduate Medicine, 60(3), 297-299.
- Peeling JL, Muzio MR. Conversion Disorder. (2020). In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK551567/
- Sadock, BJ, Sadock, VA, & Ruiz, P. (2014). Kaplan and Sadock’s synopsis of psychiatry: Behavioral sciences/clinical psychiatry (11th ed.). Chapter 13, Psychosomatic medicine, pages 465-503. Philadelphia, PA: Lippincott Williams and Wilkins.
- Harvey, SB, Stanton, BR, & David, AS. (2006). Conversion disorder: Towards a neurobiological understanding. Neuropsychiatric Disease and Treatment, 2(1), 13–20.