Pharmacologic neuroprotection in experimental spinal cord ischemia - A systematic review

Various surgical procedures may cause temporary interruption of spinal cord blood supply and may result in irreversible ischemic injury and neurologic al deficits. The cascade of events that leads to neuronal death following i schemia may be amenable to pharmacological manipulations that aim to increa se the tolerable duration of ischemia. Many agents have been evaluated in e xperimental spinal cord ischemia (SCI). In order to investigate whether an agent is available that justifies clinical evaluation, the literature on ph armacological neuroprotection in experimental SCI was systematically review ed to assess the neuroprotective efficacy of the various agents. In additio n, the strength of the evidence for neuroprotection was investigated by ana lyzing the methodology. The authors used a systematic review to conduct thi s evaluation. The included studies were analyzed for neuroprotection and me thodology. In order to be able to compare the various agents for neuroprote ctive efficacy, relative risks and confidence intervals were calculated fro m the data in the results sections. A total of 103 studies were included. S eventy-nine different agents were tested. Only 14 of the agents tested did not afford protection at all. A large variation was observed in the experim ental models to produce SCI. This variation limited comparison of the indiv idual agents. In 48 studies involving 31 single agents, the relative risks and confidence intervals could be calculated. An analysis of the methodolog y revealed poor temperature management and lack of statistical power in the majority of the 103 studies. The results suggest that numerous agents may protect the spinal cord from transient ischemia. However, poor temperature management and lack of statistical power severely weakened the evidence. Co nsequently, clinical evaluation of pharmacological neuroprotection in surgi cal procedures that carry a risk of ischemic spinal cord damage is not just ified on the basis of this study.