In various studies, amantadine and memantine have been shown to accelerate the rate of recovery from a brain injury. The time-limited window following a brain injury is characterized by neuroplasticity, or the capacity of neurons in the brain to adapt and compensate after injury. Thus, physiatrists will often start patients on amantadine as soon as impairments are recognized. There are also case reports showing improved functional recovery with amantadine treatment occurring years after the initial brain injury. There is insufficient evidence to determine if the functional gains are a result of effects through the dopamine or norepinephrine pathways. Some patients may benefit from direct dopamine stimulation with amantadine, while others may benefit more from other stimulants that act more on the norepinephrine pathway, such as methylphenidate. It is unclear if treatment with amantadine improves long-term outcomes or simply accelerates recovery. Nonetheless, amantadine-induced acceleration of recovery reduces the burden of disability, lessens health care costs, and minimizes psychosocial stressors in patients.