Abstract Details

Title Diffusion Tensor Imaging Evidence of Hypothalamic Injury in Traumatic Brain Injury Warfighters with Sleep Dysfunction

Topic Sleep

Presentation(s) P1 - Poster Session 1 (12:00 PM-1:00 PM)

Poster/Presentation
Number 5-007

Objective We hypothesized that traumatic brain injury (TBI) patients with poor sleep quality may have damage to hypothalamic sleep circuitry and that this may be detectable by MRI. We examined diffusion tensor parameters in warfighters using magnetic resonance imaging (MRI) within the hypothalamus of poor sleepers and compared them to good sleepers.

Background Sleep disorders occur in 40-70% of TBI patients, and the pathophysiology remains unknown. Increasingly, DTI has been used to evaluate gray matter structures. No prior studies have evaluated hypothalamic injury after TBI.

Design/Methods A cross-sectional retrospective review of 90 warfighters with blast TBI and loss of consciousness were included. Data obtained consisted of demographics, MRI, polysomnogram (PSG) and Pittsburgh Sleep Quality Index (PSQI). 3T MRI was used to acquire diffusion-weighted imaging and structural MRI. Diffusion tensor metrics were derived and mapped to the T1-weighted and T2-weighted images. Using a symmetric normalization diffeomorphic image transform, the hypothalamic nuclei were segmented based on the California Institute of Technology probabilistic high-resolution in vivo atlas [Pauli, 2017]. PSG and PSQI were obtained via retrospective review.

Results TBI patients within the lowest quartile of fractional anisotropy (FA) demonstrate decreased total sleep time (320 +/- 52 minutes vs. 382 +/- 19 p=0.006) on PSG and have more sleep complaints on PSQI (p=0.029) as compared to TBI patients in the highest quartile of FA. There was no difference in BMI, age or AHI among the quartiles.

Conclusions Our results suggest that microstructural differences in the hypothalami of military TBI patients correlate with both objective and subjective measures of sleep dysfunction. Biomarkers of sleep circuitry damage may serve in the future for early identification and treatment of warfighters with TBI. Longitudinal studies to elucidate the connection between hypothalamic and brainstem circuitry damage in TBI and sleep dysfunction are underway.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
	No disclosure on file
Kimbra L. Kenney, MD, FAAN	Dr. Kenney has nothing to disclose.
J. Kent Werner, Jr., MD, PhD (Uniformed Services University)	Dr. Werner has received personal compensation for serving as an employee of Cogentis Therapeutics. Dr. Werner has stock in Cogentis Therapeutics. Dr. Werner has received intellectual property interests from a discovery or technology relating to health care. Dr. Werner has received intellectual property interests from a discovery or technology relating to health care. Dr. Werner has received personal compensation in the range of $100,000-$499,999 for serving as a Neurologist with United States Navy. Dr. Werner has received personal compensation in the range of $50,000-$99,999 for serving as a CEO / CoFounder with Cogentis Therapeutics.