[Progressive bilateral hearing loss with superficial hemosiderosis of the central nervous system: contribution of cochlear implantation].

Two cases of progressive bilateral hearing loss associated with superficial hemosiderosis of the central nervous system are reported. This is a rare disease caused by repetitive hemorrhage in subarachnoid spaces with hemosiderin deposits on the brain surface and cranial nerves. MRI provided the etiologic diagnosis in both cases based on typical low-density signals from the brain, the brainstem, and the cerebellar surfaces on T1 and T2 sequences. In one case a fourth ventricle ependymoma, which was the probable cause of hemosiderosis, was also discovered. Based on a literature review, we discuss the pathophysiological hypotheses, the modalities for treating hearing loss including cochlear implantation despite retrocochlear sensorineural hearing loss.