Decreased Premotor Cortex Volume in Victims of Urban Violence with Posttraumatic Stress Disorder

Abstract

BackgroundStudies addressing posttraumatic stress disorder (PTSD) have demonstrated that PTSD patients exhibit structural abnormalities in brain regions that relate to stress regulation and fear responses, such as the hippocampus, amygdala, anterior cingulate cortex, and ventromedial prefrontal cortex. Premotor cortical areas are involved in preparing to respond to a threatening situation and in representing the peripersonal space. Urban violence is an important and pervasive cause of human suffering, especially in large urban centers in the developing world. Violent events, such as armed robbery, are very frequent in certain cities, and these episodes increase the risk of PTSD. Assaultive trauma is characterized by forceful invasion of the peripersonal space; therefore, could this traumatic event be associated with structural alteration of premotor areas in PTSD?Methodology/Principal FindingsStructural magnetic resonance imaging scans were acquired from a sample of individuals that had been exposed to urban violence. This sample consisted of 16 PTSD patients and 16 age- and gender-matched controls. Psychometric questionnaires differentiated PTSD patients from trauma-exposed controls with regard to PTSD symptoms, affective, and resilience predispositions. Voxel-based morphometric analysis revealed that, compared with controls, the PTSD patients presented significant reductions in gray matter volume in the ventral premotor cortex and in the pregenual anterior cingulate cortex.ConclusionsVolume reduction in the premotor cortex that is observed in victims of urban violence with PTSD may be associated with a disruption in the dynamical modulation of the safe space around the body. The finding that PTSD patients presented a smaller volume of pregenual anterior cingulate cortex is consistent with the results of other PTSD neuroimaging studies that investigated different types of traumatic events.

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“…The evidence for the involvement of specific neural structures in trauma-related psychopathology comes primarily from the study of PTSD, with most evidence suggesting a diminished hippocampus [25, 60, 61], smaller prefrontal structures [62–64], and possibly an enlarged amygdala [65, 66]. However, recent findings suggest sex-related heterogeneity in all these structures.…”

Stress- and PTSD-associated obesity and metabolic dysfunction: A growing problem requiring further research and novel treatments

“…Thus, verbal memory impairments are the most consistent finding in PTSD, particularly autobiographical memory [55]. Other studies have seen other structural changes with PTSD in the corpus callosum [51, 56], premotor cortex [57], and areas of the prefrontal cortex [54, 58, 59]. Notably, these are areas often affecting brain responses to food cues and influencing feeding behaviors.…”

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“…One of the best investigation results in the field of stress and trauma is the doseresponse relationship which is related to one of the laws of physics, and that means the higher the dose of trauma experience is the more possible disturbing the consequences, which might lead to severe psychiatric stress-related disorders and illnesses [2,3].…”