[Hearing disorders following spinal anesthesia].

In the few case reports of hearing loss following spinal anesthesia, complete recovery of the hearing impairment has always been described. In nine cases with hearing loss following not only spinal anesthesia but also myelography and dural puncture, the hearing of three patients did not recover or only partly returned. Two cases went to court for malpractice. Their suits could be dismissed because it appears likely that this rare complication arises only in persons with a wholly or partially unobliterated aquaeductus cochleae due to loss of perilymphatic fluid into the cerebrospinal space. Hearing loss was seen in eight of nine patients in lower frequencies around 30-40 dB. In six patients there was impairment on both sides. Recovery of normal hearing occurred in six of the nine patients. Transient hearing loss may occur more often than is generally assumed, and the symptom may remain unnoticed when a severe post-dural puncture syndrome with headache, dizziness, and nausea dominates the attention of the patient. Not all cases of hearing loss proved to be fully reversible, but the individual risk for this complication is not predictable. The use of fine-gauge needles may reduce the leakage of cerebrospinal fluid through the dural puncture and thus lower the incidence.