Achados da neuroimagem em transtorno de estresse pós-traumático e suas implicações clínicas

Abstract

Neuroimaging findings have been replicating some findings important to understanding structural and functional abnormalities associated with posttraumatic stress disorder (PTSD). The impairment in synthesizing, categorizing, and integrating a traumatic memory into a narrative may be related to a relative decrease in hippocampus volume and activation, and a decrease in activity of the prefrontal cortex, anterior cingulate, and Broca's area. The deficient extinction response mechanism to fear and emotional deregulation may possibly be related to decreased prefrontal cortex activity implicated in attenuation of negative feedback of amygdala activity. The nonhippocampally and prefrontal dependent traumatic memories are involuntarily accessed, are sensorially fragmented without a developed narrative structure, and tend to continue presenting intense emotional expression and vivid sensations. Exposure based and cognitive restructuring psychotherapeutic processes can stimulate the cognitive and integrative faculties of the brain that correspond to the structures found to be deficient in individuals with PTSD. Hence, the memory would lose emotional intensity, be more organized cognitively, and could also fade with time. Other neuroimaging findings related to psychotherapy are discussed as well as the perspectives of future neuroimaging studies in Brazil.