Spontaneous, nontraumatic clival cerebrospinal fluid fistula, treated with microscope and titanium mesh. Case report and review of the literature.

Introduction: Cerebrospinal fluid fistulas (CSF) are pathological communication between subarachnoid space and outer space. Secondary fistulas are those with known etiology - trauma infection surgery etc. Primary CSF fistulas are those with unknown etiology. Based on the localization most frequent localization of CSF are those in frontal and middle cranial fossa. Spontaneous (primary) clival fistulas are extremely rare - only 46 cases are published until now. Research question: Incidence, demographic and other predisposing factors and best treatment method of spontaneous CSF clival fistulas. Materials and methods: A comprehensive PubMed/MEDLINE search identified reported cases of spontaneous clival CSF fistula. Demographics, clinical presentation, imaging features, repair techniques, and outcomes were extracted and analyzed. We present 50 years old man with two weeks of spontaneous CSF rhinorrhea and meningitis with no history of surgery, trauma or infection. Results: A total of 47 cases were identified. Female predominance was observed (33F/14M) with mean age ∼53.7. Obesity and idiopathic intracranial hypertension were common comorbidities. Multilayer endoscopic reconstruction was the preferred technique; single-layer repair was rare. Multilayered CSFF closing was managed using transnasal transsphenoidal microscopic approach and additional titanium mesh was used with great postoperative results. Discussion: Etiology of primary clival CSFF is still unknown. There are theories based on basial artery pulsations, vertebrobasilar dolichoectasia, Marfan syndrome, clival congenital dysplasia. Plausible theory is osteolysis caused by chronic infection in this area. Despite localization operative endoscopic or microscopic treatment is the gold standard for primary CSF fistulas with excellent outcomes and preventing possible complications.