Post-lumbar Puncture Hearing Loss: A Rare Case of Reversible Presumed Secondary Endolymphatic Hydrops

Secondary endolymphatic hydrops (SEH) is an uncommon complication of cerebrospinal fluid (CSF) pressure changes. The authors report a rare case of presumed SEH following lumbar puncture with complete recovery of hearing after expectant management. A 46-year-old male developed sudden-onset left ear fullness and diplacusis monauralis 5 days after a diagnostic lumbar puncture. This occurred alongside a post-lumbar puncture headache. Pure-tone audiometry demonstrated bilateral air-conduction threshold elevation at 250 Hz, worse on the left. Given these symptoms and audiometric findings compatible with an endolymphatic hydrops mechanism, and the temporal relationship to the lumbar puncture, a presumed diagnosis of SEH was made. The patient was managed conservatively with serial audiometry, achieving full hearing recovery and complete resolution of auditory symptoms 17 days after onset. This case illustrates a rare but reversible presentation of presumed SEH, resulting from a probable CSF leak causing reduced pressure, negative perilymphatic pressure, and possible endolymphatic space dilation and hydrops. Recognition of post-lumbar puncture auditory symptoms is crucial, even in the absence of initial hearing complaints. Expectant management with close monitoring may be appropriate in selected patients with favourable prognostic features, including milder low-frequency hearing loss, absence of vestibular symptoms, and a transient underlying CSF disturbance.