Psychogenic (functional) movement disorders: Medico-legal context

Abstract

Psychogenic (or functional) movement disorders are disorders of presumed psychiatric etiology, although the pathophysiology is not completely known. Most are conversion disorders and movements are involuntary. Some patients have factitious disorder or malingering, when the movements are voluntary. Factitious disorder also has a psychiatric etiology, but malingering is goal directed behavior without psychiatric disturbance. Most authorities believe that these patients are rare, but that we cannot easily separate them from the large majority with conversion. Hence, generally all are considered to have conversion. The diagnosis of factitious and malingering could be accomplished if physicians had a good test for lying, but this is not available. Secret surveillance can be helpful, but physicians generally don’t do this. Are such patients disabled? Studies have confirmed a high level of physical and mental disability, and the patients have a poor prognosis. Hence, it would be reasonable to support disability insurance. Patients with malingering should not be entitled, but most patients are not malingerers. If a functional movement disorder arises after an accident, should they get compensation. Given that this is a real disorder and the accident triggers the disorder, the answer should be yes.