Abstract
We herein report the onset of transient bilateral hearing loss in a patient which occurred after undergoing spinal anaesthesia. A 52-yaer-old female underwent lumbar anaesthesia for surgery on a fracture in her left patella. The next day, she had headache and on the third postoperative day she complained of bilateral tinnitus and earfullness. A pure tone audiogram on the fourth postoperative day revealed a binlateral sensorineural hearing loss in the low frequency range. A few days after medication was started, her hearing returned to normal. It has been suggested that hearing loss such as that seen in this case is due to cerebrospinal hypotonia, which is similar to headache symptoms which sometimes occur following a lumbar puncture due to a loss of cerebrospinal fluid. Such cerebrospinal hypotonia causes perilymphatic hypotonia by way of the cochlear aqueduct and then relative endolymphatic hypertonia. Low tone hearing loss is likely caused by mimicking endolymphatic hydrops due to perilymphatic hypotonia. A wide cochlear aqueduct has been reported to be related to this mechanism. However, a wide cochlear aqueduct was not found in this case based on high-resolution CT scans and few other studies have reported a wide cochlear aqueduct to be related to the onset of transient hearing loss following a lumbar puncture. We therefore conclude that such a relationship remains unclear and further study is called for to elucidate this hypothesis.
