Binge ethanol prior to traumatic brain injury worsens sensorimotor functional recovery in rats

A significant number of patients suffering from traumatic brain injury (TBI) have a high blood alcohol level at the time of injury. Furthermore, drinking alcohol in a binge-like pattern is now recognized as a national problem, leading to a greater likelihood of being injured. Our objective was to determine the consequences of a binge paradigm of alcohol intoxication at the time of TBI on long-term functional outcome using a sensitive test of sensorimotor function. We trained adult, male, Sprague Dawley rats on the skilled forelimb reaching task and then administered a single binge dose of ethanol (2 g/kg, i.p.) or saline for three consecutive days (for a total of 3 doses). One hour after the final ethanol dose, rats underwent a TBI to the sensorimotor cortex corresponding to the preferred reaching forelimb. Animals were then tested for seven weeks on the skilled forelimb reaching task to assess the profile of recovery. We found that the group given ethanol prior to TBI displayed a slower recovery curve with a lower recovery plateau as compared to the control group. Therefore, even a relatively short (3 day) episode of binge alcohol exposure can negatively impact long-term recovery from a TBI, underscoring this significant public health problem.