The neural circuitry of conversion disorder and its recovery.

Abstract

Little is understood about neural networks associated with conversion disorders. This case study reports the first investigation of the neural circuitry associated with the recovery of chronic conversion disorder. A patient with a four year history of hysterical mutism was assessed with functional MRI (fMRI) during a vocalization task, and then provided psychotherapy that attempted to reduce motivational factors that maintained mutism. The patient resumed full speech, and was readministered the fMRI vocalization task. Vocalization during mutism and following recovery of speech resulted in increases in speech-related networks, including the inferior frontal gyrus (IFG), middle frontal, and supplementary motor area of the frontal cortex, temporal and parietal cortices, and also in the primary and sensory motor regions. Following speech recovery but not during mutism, the IFG was correlated positively with the anterior cingulate cortex and negatively with the amygdala. This pattern suggests that during the conversion disorder there was impaired connectivity between speech networks and networks that regulate anxiety.