[Outcome of cochlear implantation in a patient with Chiari malformation type Ⅰ who presented with hearing loss]

Summary Chiari malformation type Ⅰ（CMI） is a disorder characterized by tonsilla cerebelli herniating into an underdeveloped posterior cranial fossa, hearing loss is often covered by more striking neurological symptoms. Hearing loss in this syndrome is not specific in terms of gender side, degree, age of onset, and progression. The hearing improvement after posterior fossa decompression is controversial on the basis of literature, while satisfactory result was obtained after cochlear implantation in the patient reported here, who was diagnosed as CMI with hearing loss as the main symptom. Therefore, after ensuring the integrity of the auditory pathway, cochlear implantation may be considered in CMI patients with bilateral severe or profound without other severe neurological symptoms.