Electromyographic evaluation of human detrusor muscle activity in relation to abdominal muscle activity

Simultaneous electromyographic (EMG) recordings from the bladder detrusor muscle and the inferior rectus abdominis muscle were made in six normal subjects, in four patients with lower motor neuron bladder disease and in two patients with an upper motor neuron type of bladder lesion. Results of the study demonstrate that the bladder electrodes do not record remote muscle activity from the abdominal muscles so that any increased detrusor electrical activity with abdominal contraction must have some other explanation such as a possible abdominal-detrusor reflex or the production of increased intra-abdominal pressure from abdominal contraction. The study also demonstrates that the detrusor EMG is of value in studying the physiology of the bladder in humans, is a safe and simple technique and is of value particularly in assessing neurogenic bladder disorders.