Effects of Acute Ethanol Intoxication on Spinal Cord Injury Outcomes in Female Mice

Abstract Approximately one in three traumatic spinal cord injuries (SCIs) occurs during or shortly after the consumption of alcohol. A small number of retrospective clinical studies report variable effects of alcohol intoxication on mortality, neurological recovery, and complications after SCI. Some of these studies demonstrate a protective effect of alcohol intoxication on SCI outcomes, whereas others show an increased complication risk. Pre-clinical studies in rat, ferret, and feline SCI models report a detrimental effect of ethanol intoxication on hemorrhage, motor recovery, and biochemical markers of tissue injury. However, no studies to date have investigated the neuropathological consequences of ethanol intoxication at the time of SCI or the reciprocal effect of SCI on ethanol metabolism. Therefore, we combined a pre-clinical mouse model of acute ethanol intoxication and experimental vertebral level T9 contusion SCI to investigate their interactive effects in female mice. We first investigated the effect of SCI on ethanol metabolism and found that T9 SCI does not alter ethanol metabolism. However, we did find that isoflurane anesthesia significantly slowed ethanol metabolism independent of SCI. We also determined how acute ethanol intoxication at the time of SCI alters locomotor recovery and lesion pathology. Using the Basso Mouse Scale (BMS) and CatWalk XT Gait Analysis System, we assessed locomotor recovery for 6 weeks after injury and observed that acute ethanol intoxication at the time of injury did not alter locomotor recovery. We also found no effect of ethanol intoxication on heat hyperalgesia development. There was, however, a detrimental effect of ethanol on tissue sparing after SCI. Therefore, we conclude that acute alcohol intoxication at the time of injury may contribute to the neuropathological consequences of SCI.