Orbitofrontal cortical thinning and aggression in mild traumatic brain injury patients

Abstract

IntroductionAlthough mild traumatic brain injury (mTBI) comprises 80% of all TBI, the morphological examination of the orbitofrontal cortex (OFC) in relation to clinical symptoms such as aggression, anxiety and depression in a strictly mTBI sample has never before been performed.ObjectivesThe primary objective of the study was to determine if mTBI patients would show morphological differences in the OFC and if the morphology of this region would relate to clinical symptoms.MethodsUsing structural images acquired in a 3T MRI machine, the cortical thickness and cortical volume (corrected for total brain volume) of the OFC was collected for healthy control (N = 27) subjects and chronic mTBI (N = 55) patients at least one year post injury. Also, during clinical interviews, measures quantifying the severity of clinical symptoms, including aggression, anxiety, and depression, were collected.Results MTBI subjects displayed increased aggression, anxiety, and depression, and anxiety and depression measures showed a relationship with the number of mTBI in which the subject lost consciousness. The cortical thickness of the right lateral OFC displayed evidence of thinning in the mTBI group; however, after correction for multiple comparisons, this difference was no longer significant. Clinical measures were not significantly related with OFC morphometry.ConclusionThis study found increased aggression, anxiety, and depression, in the mTBI group as well as evidence of cortical thinning in the right lateral OFC. The association between clinical symptoms and the number of mTBI with loss of consciousness suggests the number and severity of mTBI may influence clinical symptoms long after injury. Future studies examining other brain regions involved in the production and regulation of affective processes and inclusion of subjects with well‐characterized mood disorders could further elucidate the relationship between mTBI, brain morphology, and clinical symptoms.

Elevated Aggression and Reduced White Matter Integrity in Mild Traumatic Brain Injury: A DTI Study

“…An alternative interpretation of our findings could be that reduced white matter integrity in the corpus callosum results in decreased behavioral inhibition. Prior studies have documented increased aggression in patients with orbitofrontal damage (Coccaro et al, 2007 ; Epstein et al, 2016 ). Our findings indicate similar behavioral tendencies (increased aggression) associated with reduced structural integrity in the corpus callosum, which may disrupt interhemispheric signal transfer and impede cortically mediated inhibitory processes necessary for context-appropriate behavioral regulation.…”

“…Numerous studies have reported increased aggression following traumatic brain injury (Kim et al, 1999 ; Bailie et al, 2015 ; Epstein et al, 2016 ; Roy et al, 2017 ), yet few have restricted participant samples to chronic mTBI to investigate the presence of persistent and potentially long-lasting symptoms associated with brain injury. Consistent with a recent study by Epstein et al ( 2016 ), we found increased physical aggression, anger, and total aggression on the BPAQ following mTBI. Additionally, measures of aggressive attitude and total aggression on the PAI were elevated in those with mTBI.…”

“…During the acute and subacute phases of recovery, symptoms generally fall into one of three categories, including physical (i.e., headaches, dizziness and sleep disruptions), cognitive (i.e., impaired attention and memory, reduced processing speed and poor concentration) and affective (i.e., increased irritability, anxiety and depression) disruptions (Prince and Bruhns, 2017 ). Furthermore, aggression is one of the most common affective symptoms, with upwards of 40% of individuals reporting increased aggression, hostility, or irritability after sustaining a mTBI (Kim et al, 1999 ; Bailie et al, 2015 ; Epstein et al, 2016 ; Roy et al, 2017 ).…”

Near-Term Decrease in Brain Volume following Mild Traumatic Injury Is Detectible in the Context of Preinjury Volumetric Stability: Neurobiologic Insights from Analysis of Historical Imaging Examinations

“…25,26 Most studies that reported changes in regional brain volume showed changes in regions such as the frontal gyri, precuneus, temporal gyri, caudate, cingulum, and hippocampus. 6,8,15,27,28 The ITK-SNAP protocol we used is robust to discrimination of bone, fluid, and soft tissue on CT but cannot discriminate soft-tissue differences (eg, gray versus white matter) sufficiently to allow regional segmentation. Currently available regional segmentation algorithms such as FreeSurfer (http://surfer.nmr.mgh.harvard.edu) are validated for parcellation of MR imaging.…”

Veteran treatment courts: A promising solution

“…Individuals who have sustained severe TBI may exhibit organic aggressive syndrome (OAS), characterized by unplanned, non-purposeful violence in response to seemingly trivial stimuli (Wortzel & Arciniegas, ]). Mild TBI, the "signature" injury of the Iraq and Afghanistan wars (Hayward, 2008), has similarly been associated with aggressive and criminal behavior (Epstein, Legarreta, Bueler, King, & McGlade, 2016). However, personality traits, substance use, co-occurring psychiatric illness, and generalized impaired impulse control are confounding factors to the determination of a causal connection (Wortzel, Brenner, & Arciniegas, 2013).…”