Electromyogram, evoked sensory and motor potentials in neurourology

To test the integrity of the sacral neuromuscular system, the concentric needle electromyogram (EMG) is suggested as the established method to provide information on denervation and reinnervation. The electrophysiologically recorded bulbocavernosus reflex is more sensitive than the clinically performed test; its latency is, however, not a sensitive test to assess axonal lesions. Pudendal cerebral somatosensory evoked potentials (SEP) can be considered promising in patients with conus involvement. Motor evoked potentials (MEP) in perineal muscles can only be considered investigational. True sensitivity and specificity of uroneurophysiological tests is difficult to establish due to the lack of a 'gold standard' test to define the underlying neurological lesion. Therefore, good (age stratified) reference values have to be established.