The role of obesity in spontaneous temporal bone encephaloceles and CSF leak.

Objective: Temporal bone encephaloceles and cerebrospinal fluid (CSF) otorrhea can lead to life-threatening sequelae such as meningitis and cerebritis. Obesity has been associated with spontaneous CSF leaks. We wished to determine if there were differences in the body mass index (BMI) of patients with spontaneous temporal bone encephaloceles/CSF leaks and nonspontaneous temporal bone encephaloceles/CSF leaks to help determine if obesity may be associated with their development.
Study Design: Single institution retrospective comparison.
Methods: Demographic and clinical information was obtained from 20 patients treated for surgically confirmed temporal bone dehiscence leading to encephalocele and/or CSF otorrhea. Statistical analysis was performed on patients with spontaneous and nonspontaneous encephaloceles/CSF leaks to determine if there were differences in the degree of obesity between these groups.
Results: Temporal bone dehiscence was spontaneous in 11 patients, related to chronic infection in 4 patients, posttraumatic in 3 patients, postsurgical in 1 patient, and because of massive hydrocephalus in a final patient. The average BMI for patients with spontaneous encephalocele was 33.4 kg/m. The average BMI for patients with nonspontaneous encephaloceles was 27.0 kg/m. This difference was statistically significant (p = 0.02).
Conclusion: Although several previous studies have demonstrated an association of obesity with spontaneous encephaloceles or CSF leaks, this study is one of the first to demonstrate a statistically significant increase in BMI for patients with spontaneous encephaloceles and CSF leaks as compared with patients developing them for other reasons. This suggests a potential etiologic role of obesity in the development of spontaneous encephaloceles and CSF leaks.
Level of Evidence: 4.