Date of Award

Spring 2020

Project Type


Program or Major

Communication Sciences and Disorders

Degree Name

Master of Science

First Advisor

Amy E Ramage

Second Advisor

Kimberly L Ray

Third Advisor

Donald A Robin


Problem: Traumatic brain injury (TBI) is a major health concern to the public, accounting for alarming numbers of hospitalizations and emergency department visits per year. mTBI is of particular concern because of the injury’s ‘invisible’ nature. There are a lack of clinical findings on current evidence-based diagnostic protocols, and sufferers of this “silent” injury persistently complain of changes in functioning compared to their baseline abilities.

Methods: 103 active duty service members from the SCORE study comprised 3 groups: mTBI resulting from blast (bmTBI; n=32), mTBI not resulting from blast (e.g. falls, motor vehicle accidents) (mTBI; n=29), and orthopedic controls (OC; n=42). Participants completed an fMRI task assessing effort and a standardized neuropsychological battery. Whole-brain network modularity analysis was completed to determine the pathophysiology secondary to TBI, whether the pathophysiology differs based on the nature of injury, and whether altered modularity relates to cognition.

Results: Analysis of variance tests (ANOVA) revealed greater modularity in bmTBI than mTBI and OC at increased effort levels. Repeated measures ANOVAs revealed that increasing modularity values (Q) in bmTBI corresponded with increased effort level demands, while the Q in mTBI and OC was consistent across effort levels. Pearson correlations revealed minimal associations between Q and measures of processing speed. No significant correlations between Q and neuropsychological measures were observed in the OC group.

Conclusions: This study suggests that the pathophysiology of blast injury alters the modular structure of the brain in TBI to a greater extent than in TBI from other etiologies.