Audiologic and other clinical findings in a case of basilar artery aneurysm.

A patient with a large, right-sided basilar artery aneurysm was evaluated. Major symptoms included progressive hearing loss, facial numbness, occipital headaches, dizziness, and diplopia of less than a year's duration. Audiologic results indicated a low-frequency sensorineural hearing loss with marked discrepancies between ascending and descending pure-tone thresholds for the ear ipsilateral to the lesion. Auditory brain-stem response demonstrated bilateral abnormalities, but the early waves were normal. Contralateral acoustic reflexes were absent on the right and elevated on the left. Electronystagmography results showed bilaterally absent caloric responses as well as gaze nystagmus and abnormal pursuit movements. Additional audiologic results as well as radiologic and medical findings are also presented.