Diagnosis and Localization of Cerebrospinal Fluid Rhinorrhea: A Systematic Review

Background Cerebrospinal fluid (CSF) rhinorrhea results from abnormal communications between the subarachnoid and sinonasal spaces. Accurate preoperative diagnosis and localization are vital for positive clinical outcomes. However, the diagnosis and localization of CSF rhinorrhea remain suboptimal due to a lack of accurate understanding of test characteristics. Objective This systematic review aims to assess the diagnostic accuracy of various tests and imaging modalities for diagnosing and localizing CSF rhinorrhea. Methods A systematic review of the MEDLINE and EMBASE databases was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results Our search identified 4039 articles—53 cohort studies and 24 case series describing 1622 patients were included. The studies were heterogeneous and had a wide range of sensitivities and specificities. Many specificities were incalculable due to a lack of true negative and false positive results, thus precluding a meta-analysis. Median sensitivities and specificities were calculated for cohort studies of the following investigations: high-resolution computed tomography (HRCT) 0.93/0.50 (sensitivity/specificity), magnetic resonance cisternography (MRC) 0.94/0.77, computed tomography cisternography (CTC) 0.95/1.00, radionuclide cisternography (RNC) 0.90/0.50, and contrast-enhanced magnetic resonance cisternography (CEMRC) 0.99/1.00, endoscopy 0.58/1.00, topical intranasal fluorescein (TIF) 1.00/incalculable, intrathecal fluorescein (ITF) 0.96/1.00. Case series were reviewed separately. Etiology and site-specific data were also analyzed. Conclusion MR cisternography is more accurate than high-resolution CT at diagnosing and localizing CSF rhinorrhea. CT cisternography, contrast-enhanced MR cisternography, and radionuclide cisternography have good diagnostic characteristics but are invasive. Intrathecal fluorescein shows promising data but has not been widely adopted for purely diagnostic use. Office endoscopy has limited data but does not sufficiently diagnose CSF rhinorrhea independently. These findings confirm with current guidelines and evidence.

Magnetic resonance cisternography imaging findings related to the leakage of Gadolinium into the subarachnoid space

Purpose To identify magnetic resonance cisternography (MRC) imaging findings related to Gadolinium-based contrast agent (GBCA) leakage into the subarachnoid space. Materials and methods The number of voxels of GBCA leakage (V-leak) on 3D-real inversion recovery images was measured in 56 patients scanned 4 h post-intravenous GBCA injection. Bridging veins (BVs) were identified on MRC. The numbers of BVs with surrounding cystic structures (BV-cyst), with arachnoid granulations protruding into the superior sagittal sinus (BV-AG-SSS) and the skull (BV-AG-skull), and including any of these factors (BV-incl) were recorded. Correlations between these variables and V-leak were examined based on the Spearman’s rank correlation coefficient. Receiver-operating characteristic (ROC) curves were generated to investigate the predictive performance of GBCA leakage. Results V-leak and the number of BV-incl were strongly correlated (r = 0.609, p < 0.0001). The numbers of BV-cyst and BV-AG-skull had weaker correlations with V-leak (r = 0.364, p = 0.006; r = 0.311, p = 0.020, respectively). The number of BV-AG-SSS was not correlated with V-leak. The ROC curve for contrast leakage exceeding 1000 voxels and the number of BV-incl had moderate accuracy, with an area under the curve of 0.871. Conclusion The number of BV-incl may be a predictor of GBCA leakage and a biomarker for waste drainage function without using GBCA.

Evaluation of the Role of High Resolution Computed Tomography and Magnetic Resonance Cisternography in Preoperative Identification of Skull Base Defect in Cases of Cerebrospinal Fluid Rhinorrhea

Introduction: The New Zealand White (NZW) rabbit model is commonly used for the research of posterolateral intertransverse lumbar arthrodesis. The standard approach reported by many researchers are a muscle splitting approach through the intermuscular plane between multifidus and longissimus muscles. Methods: In this research the fusion bed was exposed by retracting the three groups of paraspinal muscles (multifidus, longissimus and iliocostalis) medially. Results: This alternative method showed good exposure of the transverse processes and intertransverse membrane with less bleeding from the muscles observed. No death due to surgical complication was observed out of twenty-four rabbits operated. Conclusion: An easy and safe method for performing posterolateral intertransverse lumbar arthrodesis was demonstrated and recommended as an alternative approach for surgery on New Zealand White rabbits.

Traumatic Anterior Cranial Fossa CSF Leaks

Traumatic CSF leaks are reported to complicate 10–30% of skull base fractures. CSF rhinorrhea or otorrhea may be clinically apparent but in patients with less obvious leaks, β‎2-transferrin evaluation is the most sensitive and specific confirmatory test to establish the diagnosis of CSF leakage. High-resolution CT effectively identifies the majority of skull base fractures and sites of CSF leakage. Adjunctive imaging modalities such as CT cisternography and magnetic resonance cisternography may be used for further evaluation. Most traumatic CSF leaks of the anterior cranial fossa resolve spontaneously with conservative management including bedrest, head elevation, and avoidance of activities that increase intracranial pressure. The risk of meningitis increases significantly with persistent CSF leakage beyond 1 week, and intervention in the form of CSF diversion or surgical closure of the leak should be pursued. Prophylactic antibiotics have not been shown to decrease the risk of meningitis in patients with traumatic CSF leaks.