Long-term outcomes of mild traumatic brain injury in Veterans of the second Nagorno-Karabakh war

Abstract: Objectives: This study aimed to investigate the types, frequency, and longitudinal course of post-concussive symptoms (PCS) in veterans diagnosed with mild traumatic brain injury (mTBI) during the Second Nagorno-Karabakh War, with a particular focus on persistent post-concussive symptoms (PPCS) and their association with blast exposure, loss of consciousness (LOC), and alteration of consciousness (AOC). Methods: A total of 1,280 male veterans with documented mTBI diagnoses were included. Participants were divided into blast-related and non-blast groups. PCS including headache, memory impairment, dizziness, tinnitus, sleep disturbances, and irritability were tracked at six time points (from week 1 to beyond 12 months). Individuals diagnosed with posttraumatic stress disorder (PTSD) were excluded to reduce diagnostic overlap. PPCS was defined as the presence of at least one symptom persisting beyond 3 months post-injury. Generalized Estimating Equations (GEE) were used to analyze symptom trajectories, and the effects of LOC and AOC on symptom persistence were assessed. Results: Blast exposure was significantly associated with higher early PCS rates. Symptoms such as memory impairment, dizziness, sleep disturbances, and irritability were more persistent in the blast group. AOC was more strongly associated with the development of PPCS than LOC, particularly in relation to dizziness, tinnitus, and sleep disturbances. Sleep disturbances (39.8%) and tinnitus (28.1%) were the most common persistent symptoms. LOC was not a significant predictor of long-term symptom persistence. Conclusion: Blast-related mTBI, especially when accompanied by AOC, is strongly associated with persistent post-concussive symptoms, independent of PTSD. AOC emerged as a more robust predictor of delayed recovery than LOC. These findings suggest that the persistence of PCS may reflect underlying neurophysiological effects of blast injury, not merely psychological stress. Long-term monitoring and targeted rehabilitation strategies are warranted for affected individuals.