How do you accurately diagnose and treat a patient with an unusual movement disorder that does not appear to have any objective cause? Neurologists and psychiatrists gathered last week to discuss these and other related disorders at the L’Enfant Plaza Hotel, which is one of the closest hotels to the cherry blossoms at the ongoing National Cherry Blossom Festival.
Psychogenic movement disorders (PMDs) are spectrum conditions featuring abnormal movements that have no known “organic” cause but are not consciously mediated. These movements include tremor, myoclonus, dystonia, paralysis, and paroxysms (see the video on psychogenic nonepileptic seizures). They are thought to be a type of conversion disorder, in which a person’s psychological and emotional reaction is expressed through neurologic symptoms with no identifiable tissue pathology or nerve dysfunction. The movements may be bizarre and exhibit false neurologic signs. They can sometimes occur concomitantly with identifiable organic neurologic disease, including movement disorders, as well as additional psychiatric disturbances. In fact, many patients with PMD have a comorbid psychiatric condition or have a history of traumatic experience in the distant or recent past that may have served as a trigger to initiate the behavior.
No one is sure why individuals express a particular movement and not others, although there is evidence to suggest that some patients, especially adolescents, may unconsciously “model” the movement from examples they have seen in friends or relatives. Unlike movement disorders with objective evidence of disease or injury, these movements may go away with distraction and may be entrained to match the rhythmic movement of another body part or a sound.
Neurologists specializing in movement disorders see these patients most often through referrals, some of whom go on to treat or at least follow-up with patients. Some patients may completely resolve their symptoms, at least in the short-term, with mere suggestion (potentially while under hypnosis) or with a carefully arranged and fully consented placebo treatment. There is no gold-standard treatment, although psychotherapy in its various forms is often prescribed, if it is accepted by the patient.
And that’s the major conundrum that specialists face in diagnosing and treating these patients. The patients, most of whom are female, may have been seen by many physicians who have been unable to help them or have prescribed inappropriate medications or surgical interventions to improve their condition, often without having first conducted a full differential diagnosis. These patients have often been previously diagnosed with an organic cause to their movements, and may be taken aback when told that their symptoms are psychogenic. That’s why experts agree the presentation of a PMD diagnosis to a patient is critical and must be individually tailored. Of course, neurologists must differentiate patients with a PMD from those with a factitious disorder or those who are malingering.
One of the experts in PMD, Dr. Jon Stone of Western General Hospital, Edinburgh, recently launched a Web site, Functional and Dissociative Neurological Symptoms: a patient’s guide, to help patients and others in understanding the manifestations of symptoms that occur along the spectrum of these conditions.
–Jeff Evans (video courtesy of YouTube user ETPepilepsyvideos)