Medical Student David Geffen School of Medicine at UCLA
Disclosure(s):
Ryan Lowder, BA: No financial relationships to disclose
Introduction: Traumatic brain injury (TBI) is a leading cause of morbidity in the United States. Cognitive dysfunction and emotional dysregulation are particularly burdensome, undertreated, and commonly comorbid sequelae of TBI. TBI-related disruption of frontolimbic circuitry may be a mechanism underlying the co-occurrence of these sequelae. Here, we used resting-state functional magnetic resonance imaging (rsfMRI) to test whether aberrant elevations in functional connectivity (FC) within frontolimbic circuitry predicted cognitive impairment subacutely after mild TBI.
Methods: Twenty subjects with TBI (12 male), with a mean age of 39.95 ± 16.9 years and median Glasgow Outcome Scale – Extended score of 8 (range 2-8) participated in this study on average 35.55 ± 8.09 days post-injury. We computed FC (Fisher r-to-z) between a dorsal amygdala subregion (dAmy) and previously published cognitive control regions showing vulnerability to emotional interference (i.e., superior frontal gyrus, insula, dorsal lateral prefrontal cortex, and dorsal anterior cingulate cortex). We then computed correlations between FC, potential confounds, and the Automated Neuropsychological Assessment Metrics Version 4.0 (ANAM4) followed by a multiple regression.
Results: The ANAM4 score positively correlated with age and FC between the dorsal amygdala (dAmy) and the left superior frontal gyrus (LSFG). A multiple linear regression model controlling for age demonstrated that FC between the dAmy and LSFG significantly predicted ANAM4 score (B= -125.37; t-value= -2.32; p=.036).
Conclusion : These findings provide support for the hypothesis that aberrant frontolimbic connectivity and emotional interference may be an underlying mechanism for persistent TBI-related cognitive dysfunction. Further research is needed to better characterize this mechanism
