Pseudo-Cerebrospinal Fluid Leaks of the Anterior Skull Base: Algorithm for Diagnosis and Management

Abstract

Objective Pseudo-cerebrospinal fluid (CSF) leaks are a rare cause of unilateral, watery rhinorrhea. We proposed a step-wise approach to evaluate these cases. Design It involves a single-center retrospective cohort study. Setting The setting is that of a tertiary academic medical center. Participants Ten patients with diagnosis of pseudo-CSF leak over a 21-year period were evaluated using our proposed algorithm that includes computed tomography, magnetic resonance imaging, nasal endoscopy, β-2 transferrin, intrathecal fluorescein, and surgical exploration of the anterior cranial base. Main Outcome Measures The occurrence of intracranial infection and resolution of the symptoms were evaluated at a mean follow-up of 94.4 months. Results Eight patients had history of skull base fracture or surgery. In all patients computed tomography, magnetic resonance imaging, and nasal endoscopy did not show signs of CSF leak. Beta-2 transferrin testing was performed in five patients, being negative in all of them. Intrathecal fluorescein was performed in seven patients, being negative in five and inconclusive in two. Surgical exploration was performed in five patients, definitively ruling out CSF leak. Six patients were treated with intranasal ipratropium, resolving the symptoms in all cases. Conclusion The presented algorithm provides a step-wise approach for patients with unilateral watery rhinorrhea, allowing to safely ruling out CSF leak.

Skull Base Fracture: Management in the Acute Phase

“…3 Constanzo et al described 40% of cases of posttraumatic rhinorrhea. 6 Our study found 23 cases, or 17.3%, of posttraumatic rhinorrhea. The frequency of rhinorrhea during a fracture of the anterior skull base in our study is lower than in the literature.…”

Using Ipratropium Bromide Nasal Spray Response as a Screening Tool in the Diagnostic Workup of Cerebrospinal Fluid Rhinorrhea

“…UCTR in these scenarios has been presumed to be due to a hyperactive or unopposed parasympathetic state. Reinforcing this notion, some of the patients in these series reported rhinorrhea reduction after initiating IBNS 21,22,24,25 …”

“…There have been multiple reports of UCTR being caused by non-CSF conditions, including rhinitis, 21,22 cervical sympathetic chain surgery, 23 post-procedural rhinorrhea after sedation and supplemental oxygen use, 24 head trauma or skull base fractures, 21,22,25 anterior and lateral skull base surgeries, 12,21,22,26 and other sinonasal surgeries as well. 22 UCTR in these scenarios has been presumed to be due to a hyperactive or unopposed parasympathetic state. Reinforcing this notion, some of the patients in these series reported rhinorrhea reduction after initiating IBNS.…”

“…Reinforcing this notion, some of the patients in these series reported rhinorrhea reduction after initiating IBNS. 21,22,24,25 IBNS is a quaternary amine anticholinergic medication that binds and inhibits muscarinic receptors on nasal mucosal glands. 17,27,28 IBNS has been shown to decrease the amount and duration of rhinorrhea in various forms of rhinitis in both males and females 6 years or older.…”

Leukocyte-Rich and Platelet-Rich Fibrin for Skull Base Reconstruction After Endoscopic Endonasal Skull Base Surgery

“…Diagnosis of postoperative CSF leak was based on clinical examination, imaging, and laboratory testing, following a standardized protocol. 21 Diagnosis of intracranial infection was based on clinical examination, CSF analysis, and CSF culture. A negative CSF culture did not rule out infection if clinical signs were present with a compatible CSF analysis.…”