The surgical correction of spinal deformities carries a small but signi®cant risk of injury to the spinal cord. To detect the onset and possibly reverse the e ects of surgical complication, a variety of neurophysiological monitoring procedures can be employed. The purpose of this review is to provide information regarding the various methodologies available for monitoring spinal cord and nerve root function during orthopaedic procedures. Intra-operative monitoring of cortically recorded somatosensory evoked potentials (SEPs) by peripheral nerve stimulation is of value during orthopaedic surgery and is the state-of-the-art in terms of non-invasiveness, versatility, time requirement, lateral discrimination, and ease of electrode placement. Monitoring of motor evoked potentials (MEPs) is useful particularly in combination with SEPs but is still considered investigational. Root function monitoring has limited application and requires more clinical research. Spinal Cord (2000) 38, 133 ± 139

A valid non human primate model of traumatic spinal cord injury (TSCI) is essential to evaluate and develop new treatments. In previous experiments, it has been demonstrated that a transmitter can be implanted in the macaque fasicularis monkey that measures electromyographic data from the musculature of the tail. As well, previous experiments have demonstrated that selective lesions can be created in the lower thoracic spinal cord that does not cause limb weakness and/or bowel dysfunction. The histopathological features of these lesions appear similar to human TSCI. This paper describes a method by which the EMG data can be transformed into a quantitative metric of volitional limb movement ("Q"). This metric permits an objective assessment of injury, natural recovery as well as potential efficacy of candidate treatments. KeywordsSpinal Cord Injury, Animal Model, Electromyography N. Seth et al. 162