Chronic Aspiration Pneumonitis Caused by Spontaneous Cerebrospinal Fluid Fistulae of the Skull Base.

OBJECTIVES/HYPOTHESIS: Spontaneous cerebrospinal fluid (CSF) leaks of the skull base are associated with obesity, multiparity, and elevated intracranial pressure. Although spontaneous CSF leaks often present with rhinorrhea, they can be an underdiagnosed cause of chronic aspiration pneumonitis, a complication that has not been previously reported in detail.

STUDY DESIGN

Retrospective case series.

METHODS

The authors retrospectively reviewed all patients undergoing surgical repair of CSF fistulae at the University of Southern California between 2011 and 2018 to identify those presenting with pulmonary symptoms including dyspnea, aspiration, chronic cough, and shortness of breath caused by chronic noniatrogenic CSF pneumonitis.

RESULTS

Symptomatic chronic pneumonitis was evident in six of 20 patients with spontaneous CSF rhinorrhea. Five women (mean body mass index = 36) had CSF leaks arising from the fovea ethmoidalis (n = 4) and lateral sphenoid region (n = 1). One man had a middle fossa floor dehiscence draining through the eustachian tube. All patients had bilateral ground-glass opacities in their lungs on computed tomography imaging that were attributed to spontaneous CSF fistulae arising from noniatrogenic skull base defects, and one patient underwent a biopsy of a lung lesion at another hospital showing chronic bronchiolitis and adjacent peribronchiolar metaplasia. Five patients underwent endoscopic endonasal repair using an autologous fascial graft and pedicled nasoseptal flap, and one underwent craniotomy for repair. All patients underwent successful repair with no complications or evidence of recurrence. Upon repair of the spontaneous CSF leaks, both pneumonitis symptoms and ground-glass opacities on imaging resolved in all six cases.

CONCLUSIONS

Skull base CSF fistulae should be considered as a reversible cause of chronic pneumonitis that is not alleviated or worsens with standard treatment.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:462-466, 2021.