Patients with functional movement disorders exhibit structural gray matter abnormalities in critical components of the limbic and sensorimotor circuitry, according to a recent study. These abnormalities may represent a premorbid trait rendering patients more susceptible to disease, the disease itself, or a compensatory response to disease. Researchers obtained T1-weighted MRIs on 48 patients with clinically definite functional movement disorders, a subset of functional neurologic symptom disorder characterized by abnormal involuntary movements, and on 55 age- and sex-matched healthy controls. They compared between-group differences in gray matter volume using voxel-based morphometry across the whole brain. In addition, all participants underwent a thorough neuropsychological battery. In order to determine whether confounding factors such as comorbid depression, anxiety, or childhood trauma exposure contributed to the observed structural changes, non-parametric correlation analysis was performed. They found:
- Patients with functional movement disorders exhibited increased volume of the left amygdala, left striatum, left cerebellum, left fusiform gyrus, and bilateral thalamus, and decreased volume of the left sensorimotor cortex.
- Volumetric differences did not correlate with measures of disease duration or patient-rated disease severity.
Maurer CW, LaFaver K, Limachia GS, et al. Gray matter differences in patients with functional movement disorders. [Published online ahead of print October 10, 2018]. Neurology. doi:10.1212/WNL.0000000000006514.