Neural correlates of recall of life events in conversion disorder

Freud argued that in conversion disorder (CD) the affect attached to stressful memories is "repressed" and "converted" into physical symptoms, although this has never been subject to scientific study to our knowledge.

To examine the neural correlates of recall of life events judged to be of causal significance in CD.

Case-control study. Academic research setting among 12 patients with motor CD and 13 healthy control subjects.

Stressful life events were assessed using the Life Events and Difficulties Schedule and rated by a blinded panel for their likelihood to cause CD based on the threat posed and the extent to which subsequent illness might allow escape from some of their consequences (termed escape). Recall of those events (escape condition) was compared with recall of equally threatening control events from the same epoch (severe condition) in a functional magnetic resonance imaging task.

Relative to controls, patients showed significantly increased left dorsolateral prefrontal cortex and decreased left hippocampus activity during the escape vs severe condition, accompanied by increased right supplementary motor area and temporoparietal junction activity. Relative to controls, patients failed to activate the right inferior frontal cortex during both conditions, and connectivity between amygdala and motor areas (supplementary motor area and cerebellum) was enhanced.

These data offer support for the notion that the way adverse events are processed cognitively can be associated with physical symptoms in CD. Abnormal emotion (dorsolateral prefrontal cortex and right inferior frontal cortex) and memory control (hippocampus) are associated with alterations in symptom-related motor planning and body schema (supplementary motor area and temporoparietal junction).