Functional Neurologic Disorders
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Review Article Address correspondence to Dr Jon Stone, Department of Clinical Neuroscience, Functional Neurologic Western General Hospital, Edinburgh, UK EH4 2XU, [email protected]. Disorders Relationship Disclosure: Dr Stone receives personal Jon Stone, MB, ChB, FRCP, PhD; compensation for expert testimony related to personal Alan Carson, MD, MPhil, MRCPsych, FRCP injury and negligence cases from multiple UK law firms and receives royalties from UpToDate, Inc. Dr Stone has ABSTRACT received honoraria for lectures PurposeofReview:Functional neurologic disorders, also called psychogenic, nonorganic, from the British Medical conversion, and dissociative disorders, are among the most common problems in Association and Novartis AG and travel compensation from neurologic practice. This article presents a practical guide to clinical assessment and the European Neurological treatment, incorporating emerging research evidence. This article places an emphasis Society, Movement Disorders on encouraging neurologists to use the assessment as treatment, take an active role in Society, Royal College of Psychiatrists, and from neurology educating and treating the patient, and work in a multidisciplinary way with psychiatry, departments in Amsterdam, psychology, and physical therapy. Cork, Leuven, Oxford, Recent Findings: Classification of functional neurologic disorders now emphasizes Reykjavı´k, and St Louis. Dr Carson receives personal the importance of positive diagnosis based on physical signs, not psychological features. compensation for expert Studies of mechanism have produced new clinical and neurobiological ways of thinking testimony related to personal about these disorders. Evidence has emerged to support the use of physical therapy for injury and negligence cases and has received honoraria for functional movement disorders and psychotherapy for dissociative (nonepileptic) attacks. lectures from Novartis AG and Summary: The diagnosis and management of functional neurologic disorders has entered UCB, Inc. Dr Carson serves as a new evidence-based era and deserves a standard place in the neurologic curriculum. associate editor of the Journal of Neurology, Neurosurgery, and Psychiatry,servesas Continuum (Minneap Minn) 2015;21(3):818–837. president of the executive committee of The British NeuroPsychiatry Association, and receives book royalties INTRODUCTION ache disorders. In other studies, func- from BMJ Books. Studies in many settings have demon- tional symptoms account for between Unlabeled Use of Products/Investigational strated that functional disorders are one in ten to one in three presentations to Use Disclosure: common in neurology services. Func- neurology outpatient services, depending Drs Stone and Carson discuss the unlabeled/investigational tional disorders, in this context, refer to how they are defined. use of antidepressant bodily symptoms and disorders, such Studies in movement disorder, epi- medication and transcranial as functional movement disorders or lepsy, and dizziness clinics show that magnetic stimulation for treating functional disorders. nonepileptic seizures, which are genu- whenever there is a symptom-based clinic, * 2015, American Academy ine but not related to a defined disease functional disorders will be highly prev- of Neurology. process. The term functional,despite alent. This finding mirrors the frequency drawbacks,1 is not used here as a of physical symptoms unexplained by synonym for psychogenic,butinsteadas diseases within medicine in general, such a way of describing a group of disorders as chronic widespread pain (fibromy- in which there is a functional rather than algia), chronic fatigue syndrome, and structural disturbance in nervous system irritablebowelsyndrome,whichareoften Supplemental digital content: 4 Videos accompanying this ar- functioning and where a biopsychosocial considered functional disorders. Studies ticle are cited in the text as model is critical in understanding their have shown that the proportion of pa- Supplemental Digital Content. 2 Videosmaybeaccessedbyclick- nature. In a study conducted by the tients in primary and secondary care medi- ing on links provided in the HTML, authors of this article of 3781 new cal clinics who have functional disorders PDF, and app versions of this 5 article; the URLs are provided in neurology outpatient visits in Scotland, ranges from 30% to 50%. Studies also the print version. Video legends functional diagnoses accounted for show that patients with functional dis- begin on page 833. 14% of all new visits,3 the second most orders have rates of disability and occu- common reason for a referral after head- pational impairment that match their 818 www.ContinuumJournal.com June 2015 Copyright © American Academy of Neurology. Unauthorized reproduction of this article is prohibited. KEY POINT counterparts with defined disease pro- ment of functional disorders as they h Functional disorders cesses and typically have higher rates of present in neurology. This joint effort account for between 6 psychological comorbidity. Functional between neurologists and psychiatrists one in ten to one in disorders are not a Western or modern has brought the field to the point where three presentations to invention. They have occurred histori- it is starting again to be considered a neurology, depending cally and occur around the world at a legitimate endeavor of clinical neurology how they are defined, similar frequency to that found currently as reflected in the new criteria of the and are a leading cause in the United States and Europe. Diagnostic and Statistical Manual of of disability and distress. Despite the prevalence of functional Mental Disorders, Fifth Edition (DSM-5)7 disorders in neurology practice, func- and the forthcoming International tional disorders have a low profile in Classification of Diseases, Eleventh neurology training curricula, textbooks, Revision (ICD-11).8 and research. There are several poten- This article presents a practical ap- tial reasons for this, including the split proach to thinking about, assessing, and between neurology and psychiatry at treating patients with functional disor- the turn of the 20th century, fears about ders in a neurologic setting. In particu- misdiagnosis (which reached their peak lar, we emphasize that neurologic with a study by British psychiatrist Eliot assessment does not need to be just a Slater in 1965, who suggested that most prelude to treatment, but can be the cases of ‘‘hysteria’’ were, in fact, misdiag- start of treatment itself. The article nosed cases of disease) and, perhaps also discusses how to build successful most importantly, ambivalence, espe- multidisciplinary teams for these pa- cially from neurologists, about whether tients including psychological and patients with functional disorders have physical therapies. a genuine disorder at all. Through much of the 20th century, functional disorders CHANGES IN TERMINOLOGY became almost invisible as a clinical AND CLASSIFICATION problem, although the evidence is that Terminology has been, and will proba- their frequency did not change. Neurol- bly continue to be, a problem for these ogists went about their jobs excluding disorders. Neurologists have tended to disease but rarely making positive diag- ignore the psychiatric terms of conversion noses or getting involved in manage- disorder (as referenced in the Diagnostic ment of functional disorders. Psychiatric and Statistical Manual of Mental Dis- models have dominated classification, orders, Fourth Edition [DSM-IV])9 and etiology, and treatment, especially dissociative motor/seizure disorder (as Freud’s conversion model, which pro- referenced in the International Classi- posed that stress was ‘‘converted’’ into fication of Diseases, Tenth Revision physical symptoms. In reality, however, [ICD-10]),10 perhaps partly because the few of these patients actually saw terms demand a psychosocial formula- psychiatrists for treatment. For patients, tion that neurologists have not been the net result has often been abandon- trained to assess. ment by health professionals with ei- ther no diagnosis or misdiagnosis with a Conversion Disorder (Functional disease label such as epilepsy or multi- Neurologic Symptom Disorder) ple sclerosis (MS). in the Diagnostic and Statistical In the past 20 to 25 years, slow but Manual of Mental Disorders, sustained progress has been made in Fifth Edition our understanding of the epidemiology, In the 2013 revision of the DSM,the clinical features, mechanisms, and treat- diagnostic criteria for conversion disorder Continuum (Minneap Minn) 2015;21(3):818–837 www.ContinuumJournal.com 819 Copyright © American Academy of Neurology. Unauthorized reproduction of this article is prohibited. Functional Neurologic Disorders were radically altered. The DSM-5 now this article have argued that this change emphasizes identification of positive could result in the following11: features, predominantly on examina- & Enable neurologists and psychiatrists tion, which are typical of a functional to develop a better mutual disorder. The previous requirement for understanding of how the diagnosis a psychological stressor has been dropped, is made and encourage psychiatrists as many patients do not have an identi- to learn relevant examination fiable stressor. Even in those who do techniques have a stressor, the relationship to the & Avoid the common situation where functional symptom may be hard to a psychiatrist fails to find any establish. In addition, a previous criteria psychological