Five new things

Purpose of review: Functional movement disorders (FMD) are commonly seen in neurologic practice, but are associated with poor outcomes. Recent years have seen a resurgence of interest in this area, with new developments in pathophysiologic understanding and therapeutic management. Recent findings: Individuals with FMD are a psychologically heterogeneous group, with many individuals having no detectable psychopathology on symptom screening measures, and possibly significant etiologically relevant life events only revealed through in-depth interviews. A randomized trial of specialist intensive physical rehabilitation compared to communitybased neurophysiotherapy in FMD has demonstrated moderate to large effect sizes for both physical and social functioning outcomes. Experimental evidence suggests an impairment in the neural systems conferring a sense of agency over movement in individuals with FMD, and may explain why movements that appear voluntary are not experienced as such. Summary: The prognosis of individuals with FMD may be improved with greater access to appropriately organized care and treatment. Neurol Clin Pract 2017;7:141–147 F unctional movement disorders (FMD) are abnormalities of movement that are altered by distraction or nonphysiologic maneuvers, and are clinically incompatible with movement disorders associated with neurologic disease. FMD are a common presentation of the wider category of functional neurologic disorder. Functional disorders are extremely common in neurologic practice, with one study demonstrating that functional neurologic disorder accounted for 15% of new referrals seen in neurology clinics, second only to headache. Despite their common occurrence, prognosis is poor, with a systematic review finding that 39% of patients were the same or worse on long-term follow-up, with high levels of physical disability and psychological comorbidity. Individuals diagnosed with FMD have traditionally been left in a therapeutic wasteland, with neither neurologist nor psychiatrist able to provide strategies to bring about symptom resolution. There have been a number of recent advances in the field of FMD, including not only a rebranding of its name, but a deeper understanding of pathophysiologic aspects of the condition, and most importantly, a pathway to successful treatment. We highlight here some rays See editorial, page 96 Department of Clinical Neurosciences, Psychiatry, Pediatrics, and Community Health Sciences (TP), University of Calgary, Canada; and St George’s University of London (ME), UK. Funding information and disclosures are provided at the end of the article. Full disclosure form information provided by the authors is available with the full text of this article at Neurology.org/cp. Correspondence to: tmprings@ucalgary.ca Neurology: Clinical Practice ||| April 2017 Neurology.org/cp 141 a 2017 American Academy of Neurology. Unauthorized reproduction of this article is prohibited. of light in a dark landscape, providing a sense of optimism to an area long equated with frustration for both patients and their care providers. What’s in a name? There has been recent debate in the literature with respect to the term psychogenic movement disorders, with a broader term, functional movement disorders, suggested to take its place. The main argument for this rebranding is that the term psychogenic implies that the etiology of the symptoms is understood as being born of the mind. However, diagnosis is made with reference to positive symptoms and signs and not on the presence of psychopathology. A psychological trigger is not possible to establish in many patients, though it is difficult to be sure if this is because it is not present or simply not recognized. The term functional has been proposed as being freer from etiologic assumptions and recognizes that the cause of these symptoms may not be evident. Functional is the second most common term used between colleagues specializing in movement disorders, and is a term used without controversy in other areas of medicine. Importantly, publication of the DSM-5 brought about changes to the criteria for conversion disorder, including its name, which now includes functional neurologic symptom disorder in parentheses. The DSM-5 criteria have also been modified to emphasize the importance of the neurologic examination, and that relevant psychological factors may not be present. Specifically, clinical findings should provide evidence of incompatibility between the symptom and a recognized neurologic condition. Psychological factors Researchers continue to explore the psychological underpinnings of FMD, with recent studies seeking to confirm the Freudian hypothesis of conversion, and conversely, to validate the removal of criteria for psychological stressors from DSM-5. A case-control study of 51 individuals with FMD evaluated self-rated measures of depression, anxiety, dissociation, and personality disorders compared to individuals with neurologic (organic) movement disorders and healthy controls. Thirty-nine percent of individuals with FMD scored in the normal range on all psychological questionnaires, compared to 38% of individuals with neurologic movement disorders and 89% of controls. Patients with FMDs had similar scores as patients with neurologic movement disorders for symptoms of depression, anxiety, and psychological dissociative symptoms, and only differed on symptoms of somatic dissociative symptoms. The study concluded that individuals with FMD are not different psychologically from individuals with neurologic movement disorders, and that a relevant proportion of individuals with FMD have no psychopathology detectable on symptom screening measures. Using the Life Events and Difficulties Schedule, Nicholson et al. evaluated severe life events (life events associated with a long-term marked or moderate threat) and escape events (the extent to which the effect of a stressor might be ameliorated by being ill with neurologic symptoms) in the year preceding symptom onset in 43 individuals with motor conversion disorder (motor symptoms thought to be psychological in origin), 28 individuals with depression, and 28 healthy controls. Fifty-six percent of individuals with conversion disorder had at least one severe event in the month before symptom onset, significantly more compared to 21% of individuals with depression (odds ratio [OR] 4.63) and 18% of healthy controls (OR 5.81). Fifty-three percent of patients with conversion disorder had a least one high escape event, which was significantly higher than in those with depression (14%) and healthy controls (0%). The majority of etiologically relevant life events were not detected on routine assessment, suggesting that in-depth and specific interviewing skills are necessary to reveal these events. Whether these life events represent transient triggers or important maintaining factors in symptoms (and therefore of treatment relevance) remains uncertain. Overall, these findings point to the heterogeneous psychological background to patients with FMD. A simplistic approach to diagnostic explanation and treatment (“this has happened because of stress, you need to see a psychologist”) fails to acknowledge this complexity. A sensitive and open-minded exploration of psychological factors potentially conferring 142 © 2017 American Academy of Neurology Tamara Pringsheim and Mark Edwards a 2017 American Academy of Neurology. Unauthorized reproduction of this article is prohibited. vulnerability to develop FMD and maintenance of symptoms is useful and should be part of an individualized approach to diagnostic explanation and treatment. This exploration may well find no relevant factors, or find factors that have conferred vulnerability but are not currently active, and explanation of diagnosis and treatment needs to have the flexibility to accommodate these common situations. Loss of sensory attenuation A major issue in attitudes towards patients with FMD is a doubt as to whether the symptoms might be voluntarily, deliberately produced. After all, the movements seen in many people with FMD have characteristics associated with voluntary movement, for example distractibility. If patients are by and large telling the truth, then one explanation could be that the system that confers sense of agency over movement is impaired in patients with FMD. There are other situations in neurology and psychiatry where movements that appear voluntary are not experienced as such, for example alien limb and anarchic hand syndromes and delusions of control in schizophrenia. Disordered function of systems conferring sense of agency for movement are commonly suggested to explain such phenomena. Sensory attenuation is a phenomenon whereby the intensity of sensation caused by self-generated movements is reduced. Sensory attenuation is believed to be important in labeling movements as self-generated, and a loss of sensory attenuation has been associated with a loss of agency for movement, and has previously been reported to be abnormal in patients with schizophrenia with delusions of control. An investigation of sensory attenuation in individuals with FMD was recently performed using a force matching paradigm. In the force matching paradigm, participants are asked to match a force delivered to the finger by pressing directly onto the finger with the other hand (the self condition), or by operating a joystick that causes a robot to press down on the finger (the external condition). Healthy participants consistently generate more force than necessary during the self condition—due to the phenomenon of sensory attenuation—compared with the external condition. Individuals with FMD are much more accurate than healthy controls in their force estimation performance in the self condition. Performance between the 2 groups did not differ for the external condition. This difference in performance between the 2 groups is thought to be due to a los