[Cochlear prosthesis implantation in superficial leptomeningeal hemosiderosis].

Superficial leptomeningeal hemosiderosis is a rare disease of the central nervous system. Chronic bleeding into the subarachnoid space causes deposition of hemosiderin in glial cells and subsequent damage to adjacent brain tissue. There is a characteristic predilection for the cerebellum and eighth cranial nerve. Accordingly, among a variety of symptoms, cerebellar ataxia and sensorineural hearing loss progressing to total deafness commonly occur. To date, the hearing loss has been believed to be purely neural. We present a case of superficial hemosiderosis in a patient with total deafness who was successfully provided with a cochlear implant. Audiometry demonstrated total bilateral cochlear hearing losses but with preserved function of the eighth cranial nerve. These findings make us conclude that in contrast to current opinion, superficial hemosiderosis can initially damage the cochlea alone. Thus, patients with total deafness due to this disorder may benefit from cochlear implantation. All patients require careful audiometric assessment, including promontory stimulation.