The effect of amantadine on acute cognitive disability after severe traumatic brain injury: An institutional pilot study

Background: Amantadine is used in the post-acute care setting to improve cognitive function after a traumatic brain injury. Its utility in the acute postinjury period is unknown. In this pilot study, we sought to examine the effect of amantadine on short-term cognitive disability among patients with a severe traumatic brain injury and hypothesized that patients receiving amantadine would have a greater improvement in disability throughout their acute hospitalization. Methods: We performed a prospective, observational study of patients ≥18 years with severe traumatic brain injury (Glasgow Coma Scale ≤8) at a level I trauma center between 2020 and 2022. Patients with penetrating trauma, death within 48 hours of admission, and no radiographic evidence of intracranial pathology were excluded. Patients were grouped according to whether they received amantadine. Our primary outcome was the change in cognitive disability, measured by the Disability Rating Scale (DRS), over the index hospitalization. Results: There were 55 patients in the cohort: 41.8% (n = 23) received amantadine and 58.2% (n = 32) did not. There were higher rates of motor vehicle collisions (65.2% vs 46.9%, P = .02), diffuse axonal injury (47.8% vs 18.8%, P = .02), intracranial pressure monitor use (73.9% vs 21.9%, P = .0001), and propranolol use (73.9% vs 21.9%, P = .0001) in the amantadine. There was a larger improvement in DRS scores among patients receiving amantadine (7.8 vs 3.6, P = .001), and amantadine independently predicted improvement in DRS scores (β, 1.61; 95% confidence interval, 0.20–3.02, P = .03). Rates of discharge to traumatic brain injury rehabilitation were significantly higher in the amantadine group (73.9% vs 21.9%, P = .0002). Conclusion: Among patients with severe traumatic brain injury, amantadine use in the acute postinjury period may be associated with an improvement in cognitive disability and discharge to traumatic brain injury rehabilitation.