Characterization of pain and fatigue following deployment-related mild traumatic brain injury (P5.149)

Objective: The objective of this research was to explore the relationship between fatigue and chronic pain in military Service Members and Veterans following deployment related mild traumatic brain injury (mTBI). Background: Chronic pain and fatigue are common following military deployment, particularly in those who sustain mTBI. Fatigue is a subjective symptom with many dimensions including general tiredness, difficulty sustaining alertness, reduced activity, and decreased motivation. Fatigue accompanies chronic pain in disorders such as fibromyalgia. We measured correlations of 1) chronic pain with the dimensions of fatigue, and 2) whole brain resting state (RS) functional connectivity with pain symptoms. Design/Methods: This was a secondary analysis of cross-sectional data obtained in the Concussion, Fatigue and Community Reintegration Study conducted at the NIH Clinical Center, in which 28 male active duty Service Members and Veterans with history of deployment related mTBI were enrolled. Measures completed by participants included the Brief Pain Inventory, Neurobehavioral Symptom Inventory and Multidimensional Fatigue Inventory (MFI). All participants underwent 3T MRI, 26 with an additional RS sequence. The most frequent type of pain was chronic headache, so scores on headache related questions from the NBSI (NBSI-HA) were combined for correlation with the total MFI and MFI subscale scores. Results: After correcting for multiple comparisons, significant correlations were found in several subscale scores of the MFI, including general fatigue, reduced activity, and mental fatigue. RS correlations with NBSI-HA scores were found in several regions including left anterior cingulate gyrus and right insula that did not survive conservative multiple comparisons correction. Conclusions: This exploratory analysis suggests that severity of headache pain and degree of fatigue are interrelated following mTBI, and the most prominent dimensions of fatigue are general, mental and reduced activity, rather than reduced motivation. Study Supported by: National Institute of Neurological Disorders and Stroke Clinical Neuroscience Program Disclosure: Dr. Lewis has nothing to disclose. Dr. Knutson has nothing to disclose. Dr. Wassermann has nothing to disclose.