[Differential diagnostic problems in cerebellopontile angle tumors? A case report].

A patient, suffering from otosclerosis of the right ear, was stapedectomized in 1977. Due to bleeding into the oval window during surgery, a persistent deficit of inner ear performance occurred, causing vertigo and hearing loss of high frequencies, in the right ear. As vertigo increased over the years, the patient underwent extensive otological and neurological examinations without result. Because of anamnestic data all interest was focussed on the right ear, and even gas cisternography was performed on the right side only. Due to a left-side sudden hearing loss, the patient came to the Freiburg ENT Hospital in 1981. ERA examinations and, finally, gas cisternography revealed a tumour--meanwhile confirmed by surgery (acoustic neurinoma)--of the left cerebello-pontine angle. As a consequence of this it must be pointed out that in all cases of unilateral or bilateral loss of hearing of the inner ear and vertigo of unclear etiology, ERA investigations and bilateral gas cisternography should be performed.