Poster B140, Sunday, March 26, 8:00 – 10:00 am, Pacific Concourse
Measures of Functional Networks Correlate with Chronic Symptom Status in Patients with Traumatic Brain Injury
Keith Main1,2,3, Anna-Clare Milazzo2,3, Bernard Ng3, Salil Soman2,3,4, Jordan Nechvatal2,3, Jennifer Kong2, Stephanie Kolakowsky-Hayner5, Ansgar Furst2,3, J. Wesson Ashford2,3, Michael Greicius3, Maheen Adamson1,2,3; 1Defense and Veterans Brain Injury Center, 2War Related Illness and Injury Study Center, 3Stanford University School of Medicine, 4Harvard University Medical School, 5Santa Clara Valley Medical Center
The presentation of chronic, cognitive symptoms in patients with traumatic brain injury (TBI) may be due to alterations in neural network connectivity. Using resting-state fMRI and diffusion tensor imaging (DTI), we examined functional and structural connectivity in 23 TBI patients with self-reported, chronic symptoms and 34 diverse controls (5 with moderate-to-severe TBI, 13 with a history of minor head injury, 16 with no history of head injury) without symptoms. Chronic symptoms included deficits in memory, attention, language, and visual perception. We hypothesized that chronic symptom status would correlate with altered functional connectivity in predefined regions of the dorsolateral prefrontal and lateral parietal cortices (executive control network). Regression analyses demonstrated that chronic symptoms significantly predicted decreased connectivity in the left executive control network. The same analysis including the 5 moderate-to-severe TBI patients in the chronic symptom group resulted in non-significance. This suggests that chronic symptoms are operative, not TBI status. Additional between-group tests showed decreased connectivity for the left dorsolateral prefrontal cortex in the chronic symptom group. Further tests on 14 large-scale, resting-state networks revealed a decrease in connectivity in the chronic symptom group between the following networks: left executive control, retrosplenial/medial temporal, and precuneus/posterior cingulate. Structural connectivity, measured by fractional anisotropy, correlated with initial injury severity but not chronic symptom status. Our results suggest that a decrease in functional connectivity in the left executive control network, particularly connections with the left dorsolateral prefrontal cortex, aligns more closely with chronic symptom status than injury severity.
Topic Area: EXECUTIVE PROCESSES: Other