Spontaneous cerebrospinal fluid effusion of the temporal bone: repair, audiological outcomes, and obesity.

OBJECTIVES/HYPOTHESIS: Spontaneous occurrence of otogenic cerebrospinal fluid (CSF) effusion is now far more prevalent than causes related to infections, prior surgeries, or trauma-trends that may be increasing because of higher rates of obesity and improved diagnostic awareness. In our patient cohort with spontaneous CSF effusion, we report its association with obesity and audiological findings before and after surgery.

STUDY DESIGN

Retrospective study.

METHODS

In our 45 patients (46 ears) with CSF effusion (with or without lateral skull base meningoencephaloceles), we report clinical data, imaging studies, audiogram results, operative techniques, and recurrence rates. Causes included 33 spontaneous, 10 due to chronic otitis media, one iatrogenic, and one traumatic.

RESULTS

Body mass index (BMI) averaged 35 overall (37 for spontaneous type and 32 for nonspontaneous type). Surgical repair of skull base defect was performed using three middle fossa approaches, 24 combined transmastoid/middle fossa, and 19 transmastoid alone. Overall recurrence of CSF leaks was 6.5%. Thirty patients had audiograms available. Sensorineural hearing loss occurred in 10% of patients. Air-bone gap improved by ≥ 15 dB in 20% of patients and worsened by ≥ 15 dB in 6.7% of patients.

CONCLUSION

Patients with spontaneous CSF effusion had a BMI higher than in the nonspontaneous group, but the difference was not statistically significant. However, the dramatic trend toward spontaneous CSF effusion heightens the need for clinician's acumen for diagnosis, particularly in overweight/obese patients. Our audiological outcomes confirm the efficacy of surgical approaches in correcting conductive hearing loss and preserving bone conduction, although hearing loss is a risk during surgical repair.

LEVEL OF EVIDENCE

4. Laryngoscope, 124:1204-1208, 2014.