The need for standardization of the valsalva leak-point pressure.

The Valsalva leak-point pressure is a new test being advocated for evaluation of urethral sphincter function. However, there is currently no standardized technique for performing the test, and therefore it is difficult to draw conclusions regarding its ability to define the degree of function or dysfunction of the urethral sphincter mechanism. This article reviews the current literature regarding the parameters and techniques for performing the Valsalva leak-point pressure test. Based on what is known, recommendations for testing parameters and conditions under which the test should be performed are provided. This test may play a role in the evaluation of the urethral sphincter and give prognostic information regarding surgical outcomes, but first the technique for performing the test should be standardized and agreed upon. Until this is done no general conclusions can be drawn regarding the usefulness of this test in the evaluation of the incontinent woman.

Peripheral circular contours inhibit the visual orientation control system.

Peripheral visual stimulation with a tilted luminous frame has long been known to influence both body orientation and the apparent tilt of objects. Peripheral visual inputs along with vestibular and somaesthetic components thus constitute a multi-channel perceptual orientation control system. Surrounding the visual induction pattern with a luminous circle reduced the effectiveness of the visual channel to about 23% of maximum, whereas inscribing a circle within the luminous frame was without effect. This finding suggests a simple method for dealing with undesirable visual-vestibular interactions and an explanation for some instances of disorientation.