Cystometry and simultaneous electomyography from the striated uretheral and anal sphincters and from levator ani.

For more than one decade, we have used the cystometry-electromyography (EMG) investigation as a clinical method in patients with known or suspected neurologic disorders in whom a defect in bladder emptying, in spite of an active detrusor contraction, is found at cystometry. The electomyographic activity during bladder filling and micturition has also been studied in healthy subjects. Among other things, a voluntary control of the external urethral sphincter relaxation--independent of the degree of bladder filling--was found in most of these healthy volunteers. The cystometry-EMG investigation is easy to perform and gives reliable information as to whether a detrusor-sphincter dyssynergia exists. This information is indispensable for the choice of therapy in neurogenic cases with infravesical obstruction. In patients with upper motor neuron lesions a detrusor-sphincter dyssynergia was found when performing the ice water test. In some cases, the sphincteric contraction was so strong that the ice water was prevented from being expelled by a forceful detrusor contraction. Such false negative ice water tests can be avoided by recording the intravesical pressure when performing the test.