Functional movement disorders (FMD), (formerly called psychogenic movement disorders), are conditions of abnormal motor function that cannot be attributed to known organic causes. FMD are some of the most disabling conditions seen in neurologic practice, but are believed to be quite common, representing up to 20% of patients. Although known to be a common disorder often leading to chronic disability, research efforts in FMD have been far behind those in other neurologic disorders such as multiple sclerosis or Parkinson’s disease. While there is emerging evidence implicating alterations in brain circuits involved in sensorimotor and emotion processing, on a whole, the neurobiological basis of FMD is poorly understood and there are currently no standardized treatment guidelines for FMD.
In 2014, the Frazier Rehab Institute at the University of Louisville developed a standardized, multidisciplinary one-week inpatient treatment for individuals with FMD, the Motor Retraining (MoRe) program, during which patients receive three hours of physical, occupational and speech therapy and one hour of cognitive behavioral therapy per day for five consecutive days. Since its establishment, the MoRe program has shown excellent treatment outcomes, leading to significant symptom improvement in 86.7% of patients at discharge, with this improvement being maintained in 69.2% of patients at a six month follow-up. However, despite success from this approach, it is unclear how this treatment affects the underlying neural pathways involved in FMD, and what factors predict long-term treatment success.
Therefore, in collaboration with the Movement Disorder Clinic at the Frazier Rehab Institute, this study was designed to understand the nature of neurobiologic mechanisms leading to abnormal movement control in FMD, and to investigate structural and functional neuroimaging data before and after the MoRe treatment intervention. The currently prevailing biopsychosocial model of FMD postulates dysfunction in attentional control networks, abnormal integration of sensorimotor functions and motor inhibition pathways and overactivation of emotional circuits, leading to loss of agency of voluntary movements. Our approach will allow us to better understand these neural network dysfunctions in FMD and to begin to define predictive markers of rehabilitation success. The longer-term goal will then be to incorporate these methods into development of biomarkers for this condition to aid in establishing targeted therapies.