Objective. To highlight the advantages and limitations of modern neurotoxicologic techniques useful in assessing neurotoxicity in spinal cord and nerve roots.

Methods. Techniques discussed include electrophysiologic and behavioral testing and, most important, neuropathologic evaluation of appropriately sampled and processed neurological tissue. References are given to details of methodologic procedures commonly used in neurotoxicity studies, and a detailed appendix is included for preparation of fixative and processing of tissue for electron microscopy. Tissue culture techniques and animal models, including dog spinal cord and rat peripheral nerve preparations, are also evaluated for their usefulness in neurotoxic testing. Background is provided describing the categories of neuropathologic change associated with several classes of known neurotoxic agents and specific neuronal processes affected by these agents.

Results. This information can be used to help develop a focused scientific approach to the problems associated with continuous spinal anesthesia.

Conclusion. The use of neuropathologic methods to evaluate tissue injury is of the utmost importance in establishing the pathogenic mechanisms of injury and likelihood for repair and functional recovery.