Cochlear Implantation: A Treatment Approach of Hearing Loss in Superficial Siderosis

Superficial siderosis (SS) is a chronic condition characterized by progressive hemosiderin accumulation in the central nervous system (CNS) due to chronic subarachnoid hemorrhage. Common clinical features include progressive bilateral sensorineural hearing loss (SNHL), cerebellar ataxia and myelopathy. The aim of the study was to analyze the clinical presentation, management, and outcomes of patients affected by SS with bilateral severe-to-profound hearing loss and treated with cochlear implantation (CI), with a particular focus on the course of hearing benefit.

A retrospective monocentric review was performed, including patients affected by CNS SS and profound SNHL that underwent CI between January 2012 and December 2021. Outcomes were assessed by comparing pre- and post-operative tonal and vocal hearing thresholds together with verbal perception tests.

A total of 4 patients were identified, with a mean follow-up time of 48.25 months. All patients showed significant improvement of hearing threshold and verbal perception in the first 6 months after surgery (preoperative mean aided PTA of 58.3 dB with a mean open-set speech perception score of 20.3% versus postoperative mean PTA in bimodal stimulation of 41.1 dB and open-set speech perception score of 60.1%). At the last follow-up evaluation, despite progressive deterioration of auditory performances, all patients were users and maintained subjective benefit from CIs.

Patients affected by SS who underwent CI showed a significant improvement in auditory and auditory-verbal performances in the first post-operative period. Despite a progressive decline of hearing benefit due to retrocochlear disease progression, CI represents valid support for lip-reading and spatial orientation even in the advanced stages of the disease.