Citation

Papesh M, Elliott JE, Callahan ML, Storzbach D, Lim MM, Gallun F. J. Neurotrauma 2019; 36(5): 702-712.

Affiliation

Oregon Health and Science University, Department of Otolaryngology, Head and Neck Surgery, Portland, Oregon, United States ; frederick.gallun@va.gov.

Copyright

(Copyright © 2019, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2018.5801

PMID

30113267

Abstract

Many military Service Members and Veterans who have been exposed to high-intensity blast waves suffer from traumatic brain injury (TBI), resulting in chronic auditory deficits despite normal hearing sensitivity. The current study sought to examine the neurological cause of this chronic dysfunction by testing the hypothesis that blast exposure leads to impaired filtering of sensory information at brainstem and early cortical levels. Groups of blast-exposed and non-blast-exposed participants completed self-report measures of auditory and neurobehavioral status, auditory perceptual tasks involving degraded and competing speech stimuli, and physiological measures of sensory gating, including prepulse inhibition and habituation of the acoustic startle reflex and electrophysiological assessment of a paired-click sensory gating paradigm. Blast-exposed participants showed significantly reduced habituation to acoustic startle stimuli and impaired filtering of redundant sensory information at the level the auditory cortex. Multiple linear regression analyses revealed that poorer sensory gating at the cortical level was primarily influenced by a diagnosis of TBI, while reduced habituation was primarily influenced by a diagnosis of posttraumatic stress disorder. A statistical model was created including cortical sensory gating and habituation to acoustic startle, which strongly predicted performance on a degraded speech task. These results support the hypothesis that blast exposure impairs central auditory processing via impairment of neural mechanisms underlying habituation and sensory gating.

Language: en

Keywords

ADULT BRAIN INJURY; Behavior; ELECTROPHYSIOLOGY; TRAUMATIC BRAIN INJURY