Sensitivity and specificity of brain stem potentials as a means of differentiating cochlear and retrocochlear disorders (acoustic neuromas).

Between 1980 and 1985 we examined a fairly large group of patients for retrocochlear disorders. Every patient was examined by at least two procedures, registration of brain stem potentials and CT; we had also magnetic resonance images taken of some of these patients. We diagnosed a total of 37 acoustic neuromas in 34 of the patients examined. From our study a conclusion can be drawn about the sensitivity and specificity of brain stem potentials as evidence of an acoustic neuroma. The rate of false negative diagnoses is about 6%. The false positive rate is considerably higher, and it is discussed in detail. The clinical utility of brain stem potentials is illustrated with two case histories. Because of the method's low false negative rate, cochlear disorders diagnosed by registering brain stem potentials need not as a rule be confirmed by modern imaging procedures.