Acoustic neuromas. Diagnostic efficiency of various test combinations

In the majority of diagnostic tests usually used in the search for acoustic tumors, there is a large difference in the outcome between patients with and without tumors. Because of a possible coherence between the tests applied, a statistical analysis of this connection was performed with the aid of a logistic model. The best single investigation used to differentiate between patients with and without tumors was tomography of the internal acoustic meatus. This examination was used in combination with the differential caloric test and the alternate binaural loudness balance recruitment test to differentiate completely between patients with and without tumors. Results of other examinations did not contribute significantly to the differentiation between patients with and without tumors. This factor did not render the other examinations superfluous because the analysis was valuable only in patients with a hearing level better or equal to 80 dB. By applying the other tests, information was obtained on pressure conditions in the internal acoustic meatus and possible difficulties at surgery, as well as information about the size of the tumor.