[Auditory brainstem responses in the diagnosis of retrocochlear hearing loss: selected case reports].

In this study, four cases of patients with retrocochlear hearing loss are presented (acoustic neuroma, cerebellopontine angle tumour, the fourth ventricle region tumour, inflammatory or vascular lesions in the fourth ventricle region). Standard audiometric tests, auditory brainstem response and radiological examinations such as CT scan and MRI were performed in all patients. The abnormal ABR observed in all cases suggested retrocochlear hearing loss. The presence of retrocochlear disorders was confirmed by CT or MRI. The analysis of presented cases showed that the abnormal ABR results should be a sufficient basis for referring the patient to MRI examination.