Right temporal cortical hypertrophy in resilience to trauma: an MRI study

Abstract

BackgroundIn studies employing physiological measures such as magnetic resonance imaging (MRI), it is often hard to distinguish what constitutes risk-resilience factors to posttraumatic stress disorder (PTSD) following trauma exposure and what the effects of trauma exposure and PTSD are.ObjectiveWe aimed to investigate whether there were observable morphological differences in cortical and sub-cortical regions of the brain, 7–8 years after a single potentially traumatic event.MethodsTwenty-four participants, who all directly experienced the 2004 Indian Ocean Tsunami, and 25 controls, underwent structural MRI using a 3T scanner. We generated cortical thickness maps and parcellated sub-cortical volumes for analysis.ResultsWe observed greater cortical thickness for the trauma-exposed participants relative to controls, in a right lateralized temporal lobe region including anterior fusiform gyrus, and superior, middle, and inferior temporal gyrus.ConclusionsWe observed greater thickness in the right temporal lobe which might indicate that the region could be implicated in resilience to the long-term effects of a traumatic event. We hypothesize this is due to altered emotional semantic memory processing. However, several methodological and confounding issues warrant caution in interpretation of the results.Highlights of the articleFollowing a traumatic event, most people do not develop long-lasting trauma-related symptoms.In a group who experienced a traumatic event 8 years prior, but showed low levels of trauma-related symptoms, we observed increased cortical thickness in the right temporal lobe.The right temporal lobe is implicated in emotional semantic memory processing, and thus might be associated with resilience to the long-term effects of a traumatic event.

Gray matter volume differences between lower, average, and higher pain resilience subgroups

“…This finding has parallels to recent results of Nilsen et al. (2016) who reported increased cortical thickness in right temporal lobe regions, including the ITG, among trauma‐exposed cohorts with posttraumatic stress symptoms compared to nontraumatized controls. These authors posited their results suggest increased right temporal lobe volume in their sample reflected negative long‐term effects of traumatic events, an interpretation that aligns with our finding of correspondence between reduced capacities to manage adversity and increased ITG GMV.…”

Cortical thickness reduction in combat exposed U.S. veterans with and without PTSD

“…Some studies demonstrated a negative correlation between cortical thickness and PTSD severity (Corbo et al, 2014; Lindemer et al, 2013; Liu et al, 2012; Sadeh et al, 2016). Greater cortical thickness was previously associated with resilience and enhanced recovery from PTSD symptoms (Dickie et al, 2013; Lyoo et al, 2011; Nilsen et al, 2016), although not without inconsistencies (Helpman et al, 2016). …”

Serum Neurosteroid Levels Are Associated With Cortical Thickness in Individuals Diagnosed With Posttraumatic Stress Disorder and History of Mild Traumatic Brain Injury

“…12,[21][22][23] Additionally, the thicker the cortex, the better resilience and recovery from PTSD symptoms in those diagnosed with PTSD. [24][25][26] In mTBI, there is also evidence of widespread GM alterations 27 as well as global brain volume and precuneal GM volume decreases at 1-year postinjury follow-up. 28 Furthermore, decreased volume of subcortical GM structures, including the thalamus, hippocampus, amygdala, and putamen, has been reported following mTBI.…”