0941 Impact Of Light Therapy On Brain Structure And Simple Reaction Time Following Mild Traumatic Brain Injury. (12th April 2019)

• Record Type: Journal Article
• Authors: Bajaj, Sahil; Dailey, Natalie S; Raikes, Adam C; Vanuk, John R; Grandner, Michael A; Weber, Mareen; Rosso, Isabelle M; Rauch, Scott L; Killgore, William D
• Is Part Of: Sleep. Volume 42(2019)Supplement 1
• Page Start: A378
• Page End: A379
• Publication Date: 2019-04-12
• Subjects: Sleep -- Physiological aspects -- Periodicals; Sleep disorders -- Periodicals; Sommeil -- Aspect physiologique -- Périodiques; Sommeil, Troubles du -- Périodiques; Sleep disorders; Sleep -- Physiological aspects; Sleep -- physiological aspects; Sleep Wake Disorders; Psychophysiology; Electronic journals; Periodicals; 616.8498
• DOI: 10.1093/sleep/zsz067.939
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Introduction: Mild traumatic brain injury (mTBI) is often associated with persistent post-concussive symptoms and sleep disruption. Emerging evidence suggests that circadian timing and some aspects of sleep quality may be improved through daily morning exposure to blue light therapy (BLT). However, the effect of BLT on brain structure in the mTBI population remains unknown. Methods: Neuroanatomical data were collected from 34 healthy controls (HCs) and 28 mTBI individuals. Individuals with mTBI either underwent six-weeks of BLT or placebo amber light therapy (ALT). MTBI participants were administered the Automated Neuropsychological Assessment Metrics (ANAM4) battery both before and following treatment. For the purpose of this study, only the simple reaction time (RT) data from ANAM4 battery were analyzed. Results: Compared to HCs, individuals with mTBI showed significantly lower normalized cortical volume (NCV) at baseline assessment (Cohen's d 0.5) in several brain regions. These included the caudal middle frontal gyrus (MFG), inferior parietal cortex and middle temporal cortex (MTC) within the left hemisphere and five regions, including the lateral orbitofrontal cortex, pars orbitalis (R.ParsOrb), MTC, precentral gyrus and rostral MFG within the right hemisphere. These areas of differing volume were then utilized as regions of interest (ROIs) in the main analysis of mTBI participants. There was significant reduction in RT following BLT (p = 0.008), but not following ALT (p = 0.09). There was a significant group (ALT/BLT) x time (pre/post) interaction for NCV within the R.ParsOrb (p = 0.035), suggesting that NCV within R.ParsOrb increased following BLT, but not following ALT. Moreover, following BLT, increased NCV of the R.ParsOrb was significantly correlated with decreased RT (r = -0.54, p = 0.04). Conclusion: Morning BLT may increase NCV within prefrontal areas and contribute to reductions in RT among individuals with mTBI. The primary effect of blue-light could be on sleep and circadian rhythms. This could cause observed improvements in cortical structure and reaction time, which can be considered as secondary consequence of improved sleep. Support (If Any): W81XWH-11-1-0056 (WDK) and W81XWH-12-1-0109 (SLR)