Neuroimaging Applications in Functional Movement Disorders

Functional (psychogenic) movement disorders are a subtype of functional neurological disorder, a common and disabling cause of neurological symptoms. Abnormal movement in people with functional movement disorders has specific characteristics (e.g., distractibility, variability, incongruence with deficits caused by neurological disease), allowing positive diagnosis and differentiation from other causes of movement disorder. Attempts to understand the pathophysiology of this disorder have previously focused mainly on the psychological level, emphasizing the importance of psychological trauma and adverse life events. However, the last two decades has seen a broadening of this approach to consider the neurobiological level, and brain imaging has formed a key part of this work. Here we review the available imaging evidence in functional movement disorders and explain how this evidence can help us understand more about the underlying pathophysiology of this common cause of abnormal movement control.