DEFINITION

• Conversion disorder is most simply defined as the presence of neurological symptoms (motor or sensory) without a known physiological basis.
  • The neurological symptoms must be shown to be incompatible with pathophysiology.

• Conversion disorder (functional neurological symptom disorder) is classified under the Somatic Symptom and Related Disorders section of the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5).[1]
  • Other diagnoses under this section include somatic symptom disorder, illness anxiety disorder, and factitious disorder.

• When considering this diagnosis, it is important to have a firm understanding of somatization.
  • Somatization is the expression of mental phenomena as physical (somatic) symptoms.
  • There is a continuum of unconscious/non-volitional display of symptoms (patient unaware of the non-physiologic nature of symptoms) to conscious/volitional display (patient aware of the non-physiologic nature of symptoms).
  • Also important is the difference between primary gain (positive internal motivations) vs. secondary gain (positive external motivations).
    
    • Primary gain example: A patient feels guilty about not being able to perform a task, but if there is a medical condition justifying this inability, the guilt diminishes.
    • Secondary gain example: A patient is allowed to miss work and gets financial compensation as the result of a medical condition.
    • Any given patient with conversion disorder will have primary and/or secondary gains associated.