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Summary— A practical and easily applicable method of recording cortical potentials evoked by bipolar electrical stimulation of the bladder wall is described. This constitutes an objective electrophysiological test of afferent bladder central projections. Comparison of bipolar and monopolar methods of intravesical stimulation led to the conclusion that the simpler monopolar intravesical electrode technique is unsuitable because it yields potentials contaminated by extravesical components.

Summary— A recently developed neurophysiological method by which the motor cortex in man can be electrically stimulated has been applied to the assessment of the central motor pathway to the external urethral sphincter. It was observed that there was parallel activation of the anal sphincter, the pelvic floor and the lower limb muscles, voluntary facilitation and marked inhibition during micturition. This method can be used to assess the volitional and the various segmental and suprasegmental influences on the behaviour of the external urethral sphincter. Unfortunately, the poor tolerance of subjects to the scalp sensations caused by the electrical stimulus is a major limitation to its clinical use, though this should be obviated by the introduction of a cortical magnetic stimulator.