When the grommet reveals the diagnosis: a clinical pathway for middle ear cerebrospinal fluid leakage

Purpose Middle ear cerebrospinal fluid leakage (CSFL) is an uncommon but important cause of adult middle ear effusion, often mistaken for otitis media with effusion. Delayed recognition risks serious infective complications: published series report a median 15.5-month diagnostic delay and meningitis in up to 20% of cases. This paper aimed to develop a practical pathway for recognising, investigating, referring and managing suspected middle ear CSFL in adult ENT practice. Methods This pathway combined a retrospective departmental case series, a focused PubMed literature review, and multidisciplinary expert consensus into an evidence-informed, consensus-based pathway for general ENT teams. Results Seven patients were identified (median age 65 years; four female, three male); middle ear CSFL was recognised after ventilation tube insertion in all cases, and six underwent surgery (transmastoid, middle cranial fossa or subtotal petrosectomy). These cases informed a pathway covering history taking, risk-factor recognition, biochemical confirmation, CT/MRI investigation, senior escalation, meningitis safety netting and skull base MDT referral. Conclusion Middle ear CSFL should be considered in adults with persistent clear otorrhoea after ventilation tube insertion. To our knowledge, this is the first practical pathway developed for general ENT teams and may support earlier recognition and management.