Platform pressure test in identification of perilymphatic fistula

In an effort to better define the effectiveness of the use of posturography in the preoperative diagnosis of perilymphatic fistula (PLF), a prospective investigation of the use of platform pressure posturography was performed. Six different protocols used atmospheric pressure change applied to the external auditory canal. Postural sway, monitored as the output parameter, was evaluated relative to its sensitivity and specificity in five different patient groups. Two independent surgeon groups were used to establish the final diagnosis of perilymphatic fistula. Results within a given surgeon group demonstrate varying sensitivity from 53 to 100 percent and specificity from 56 to 89 percent. Results across the two surgeon groups show nonstatistically significant changes in sensitivity and specificity, yet statistically significant differences exist between the surgeon groups for rate of surgery performed given a suspected patient group, and for rate of positive identification of PLF during surgery. We conclude that although the platform pressure test (PPT) shows promise as a test to raise preoperative suspicion for PLF, actual test performance figures cannot be calculated until a more definitive, objective, test is available to confirm the final diagnosis. The variability of selection criteria and diagnosis by surgical observation is too great to draw clear conclusions relative to test performance. Additionally, the use of vestibular rehabilitation techniques is suggested as a presurgical management strategy for a selected group of suspect patients.