Symptom Overlap and Neurobiological Similarities Between Posttraumatic Stress Disorder and Tinnitus

Many symptoms of posttraumatic stress disorder (PTSD) overlap with the psychological sequelae of tinnitus, including sleep difficulty, concentration problems, hypervigilance, and irritability. Although these two disorders are clearly distinct, they are highly comorbid, may have shared etiology, and are among the top service-connected disabilities within the VA healthcare system. This study aimed to determine neuropathophysiological similarities and differences among veterans with both PTSD and tinnitus, tinnitus only, and healthy controls. Resting-state networks were identified by previous studies and extracted to examine functional connectivity patterns. Networks included the default mode network (DMN), auditory vigilance (AUDVIG), salience (SN), dorsal attention (DAN), and emotion (EMO) networks. Functional connectivity among specific brain regions was decreased among the tinnitus only group compared to the healthy control group and was further decreased when PTSD was present with tinnitus. Findings suggest that the additive and negative effects observed symptomatically may be explained by decreased functional connectivity, especially with respect to the DMN and AUDVIG networks.