PERCUTANEOUSLY RECORDED ELECTRICAL ACTIVITY OF FOURTH SACRAL NERVE FROM SACRAL FORAMEN

(II) Percutaneous Recording of Fourth Sacral Nerve Activity in Patients

Abstract

The second, third and fourth sacral nerves, which seem to have an important role in urination, are not related clearly to the mechanism of the detrusor and the external sphincter.
In this study, electrical activity of the 4th sacral nerve and EMG of external sphincter during urination were studied percutaneously in 8 patients with neurogenic bladder, in order to know the role of the 4th sacral nerve in relation to the mechanism of urination.
Bipolar needle electrodes were inserted into the sacral foramen percutaneously by the method of sacral nerve block.
The normal pattern of the 4th sacral nerve activity during urination in humans is similar to that in normal rabbit as stated below.
1) Gradual increase of electrical activity on increasing bladder volume.
2) The most frequent activity is obtained at the point of starting urination.
3) Gradual decrease of electrical activity on decreasing bladder volume.
And in three types of neurogenic bladder in patients, abnormalities of the 4th sacral nerve were demonstrated.
The second sacral nerve activity during urination was studied in some cases.
The 4th sacral nerve activity reflected well the bladder activity and the 2nd sacral nerve activity the sphincter activity.
By observing EMG of the external sphincter and activity of the sacral nerve in combination, we can obtain more precise information on urodynamics especially in case of neurogenic bladder. This type of study on sacral nerve activity may be called uroneurometry.