Current Concepts in Diagnosis and Treatment of Functional Neurological Disorders

Abstract

IMPORTANCE-Functional neurological disorders (FND) are common sources of disability in medicine. Patients have often been misdiagnosed, correctly diagnosed after lengthy delays, and/or subjected to poorly delivered diagnoses that prevent diagnostic understanding and lead to inappropriate treatments, iatrogenic harm, unnecessary and costly evaluations, and poor outcomes. OBSERVATIONS-Functional Neurological Symptom Disorder/Conversion Disorder was adopted by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, replacing the term psychogenic with functional and removing the criterion of psychological stress as a Funding/Support: This article presents independent research part-funded by the

Gender as a Risk Factor for Functional Movement Disorders: The Role of Sexual Abuse

“…Functional movement disorders (FMD) are commonly seen in neurologic practice and are characterized by abnormal control over movements, often presenting with tremor, dystonia, and gait disorders and associated nonmotor complaints with evidence of symptom incompatibility with recognized neurologic diseases. 1 The prevalence of functional movement disorders is 2 to 3 times higher in women than in men. 2 Since the advent of modern psychiatry, a correlation between the experience of emotional trauma and psychogenic symptoms has been postulated.…”

“…Since the advent of modern psychiatry, a correlation between the experience of emotional trauma and psychogenic symptoms has been postulated . This relationship led to the original terminology of conversion disorder—the belief that stressful mood states were converted into sensorimotor neurologic processes . Despite significant criticisms and limitations of this theory, the role of stress and trauma remain important risk factors for developing functional neurological disorders .…”

Voluntary Inhibitory Control of Chorea: A Case Series

“…Nevertheless, we did not test patients’ perception of movements subsiding when performing other tasks. The ability to modulate involuntary movements and their attenuation while doing other tasks (which can resemble distractibility) might be evocative of functional disorders . However, the diagnosis of functional movement disorders is based on the presence of positive signs, other than “distractibility,” and specific elements on the neurological examination, such as inconsistency (i.e., changing patterns over time), incongruence (i.e., a clinical phenomenology discordant with recognized organically determined patterns), sudden onset of the symptoms, increase in involuntary movements with attention, and excessive fatigue or demonstration of effort .…”

Repetitive transcranial magnetic stimulation for functional tremor: A randomized, double‐blind, controlled study

“…However, as we did not measure motor evoked potentials, the exact mechanism by which rTMS acts on FT is still uncertain and will require further studies. Neuroimaging studies among patients with FMD have reported abnormal activity in networks spanning motor and limbic areas, including prefrontal areas and the anterior cingulate cortex . When Voon and colleagues performed a neuroimaging study that specifically included patients with FT, they observed decreased activation in the right temporoparietal junction and decreased connectivity between this region, the sensorimotor areas, and limbic regions in accordance with a deficit in the sense of agency.…”