Neuroimaging of Functional Movement Disorders Before and After Treatment
Leonard Faul1, Brendan Depue2, Alexandra Jacob2, Darryl Kaelin2, Alberto Espay3, Kathrin LaFaver2; 1Duke University, 2University of Louisville, 3University of Cincinnati
Functional Movement Disorders (FMD) are common, yet poorly understood disorders of abnormal motor control presenting with tremor, dystonia, gait or speech problems. The pathophysiological substrates underlying FMD remain largely unknown, which limits the development of targeted treatments. However, there is emerging evidence implicating alterations in brain circuits involved in emotional and sensorimotor processing. Using fMRI, we studied 9 FMD patients performing an emotional Go/No-Go task before and after undergoing a one-week inpatient multidisciplinary Motor Retraining (MoRe) program. Data was analyzed to examine main effects (pre>post, post>pre, within the fear>baseline contrast, as this elicited the greatest power). Data was further analyzed by including regressions with a behavioral indicator of treatment success (from a blinded rater using the psychogenic movement disorder rating scale - PMDRS), as well as functional connectivity. All analyses were thresholded at voxel-wise = p<.005 and cluster-wise = p<.05. Only post>pre changes remained significant after correction, indicating that after completing the treatment program, individuals with FMD: 1) showed increased activity in the dorsomedial prefrontal cortex (dmPFC), supplementary motor area (SMA), and primary motor cortex (PMC), 2) showed increased activation of premotor cortex (pMC), PMC, and putamen with increased motor improvement outcome, and 3) showed increased connectivity between the dmPFC and amygdala. These findings highlight an effect of the treatment program that appears to increase control over emotional response (activation of dmPFC and connectivity between dmPFC and amygdala), as well as increased integration of motor planning and response in the pMC, PMC, SMA, and putamen after treatment was performed.
Topic Area: PERCEPTION & ACTION: Motor control