D. V. Roshchina

Introduction. Currently diagnosis of cerebrospinal fluid (CSF) leak involves the use of instrumental and laboratory techniques. Computed tomography of the brain (CT brain) is the preferred instrumental method. However, it is not always effective for visualization of skull base defects less than 2 mm in size.Aim. To confirm nasal CSF leak primarily using laboratory diagnostic methods, rather than instrumental diagnostic methods.Materials and methods. Instrumental diagnosis of nasal CSF leak (outpatient): high-resolution CT brain with subsequent image analysis in multiplanar projections. Laboratory diagnosis: quantitative test of glucose in nasal fluid using test strips (Russia) and quantitative test using hexokinase method and biochemical analyzers (Japan, USA).Results. Diagnostic tactics and types of surgical treatment for 34 patients are presented. CT brain was performed in all patients, and no bone defect was found in 5 (14.7 %) cases. However, thinning of the bone tissue in the area of the cribriform plate of the ethmoid bone with the presence of a soft tissue inclusion (meningoencephalocele), as well as a low position of the olfactory fossa (8.16 ± 0.14 mm) was observed. Through laboratory diagnostics, admixture of CSF in nasal fluid was verified in 5 (14.7 %) patients. Reconstruction of CSF fistulas was performed in all patients through endoscopic endonasal access using multilayer closure technique with allo- and autografts. In the postoperative period, no recurrence of CSF leak was observed. Follow-up period ranged from 6 months to 3 years.Discussion. In verification of CSF in nasal fluid, CSF fistula diagnosis requires CT brain; in the absence of obvious defects of the skull base according to CT results, endoscopic examination of the nasal cavity and cribriform plate of the ethmoid bone should be performed without the use of invasive diagnostic methods.Conclusion. In the context of negative CT and positive laboratory results, the area of the cribriform plate of the ethmoid bone should be regarded as the most likely source of CFS.

Background. The frequency of traumatic cerebrospinal fluid (CSF) leaks in fractures of the skull base is 33–40 %, intracranial purulent complications occur in 10–37 % of cases, and mortality rate is 30 % even with antibiotic therapy. The difficulty of diagnosing CSF leaks in patients with severe traumatic brain injury is caused by several factors: impossibility of gathering complaints from a patient with decreased alertness; difficulty to position a patient for instrumental diagnostics due to concomitant injuries; artificial ventilation; cerebrospinal fluid leak being masked by hemorrhagic secretions from the nose.Aim. To review the effectiveness of various diagnostic methods and algorithms for detection of cerebrospinal fluid leak and to access their feasibility in cases of potentially penetrating traumatic brain injury.Results. The study identified the main challenges of diagnosing cerebrospinal fluid leaks in intensive care patients, including difficulties in performing invasive neuroimaging methods, challenges in collecting nasal secretions for laboratory detection of CSF-specific markers, and the absence of fluorescein approved for intrathecal use in the Russian Federation. It was established that in severe cases, the most informative methods are brain CT and glucose oxidase test with radionuclide cisternography recommended in cases of uncertain results. Upon confirmation of cerebrospinal fluid leak, endoscopic nasal cavity revision and, if necessary, CSF fistula repair are advised.Conclusion. The findings emphasize the need for further research and refinement of diagnostic algorithms to improve the accuracy of traumatic CSF leak detection in patients with severe traumatic brain injuries.

CSF fistulas of the lateral recess of the sphenoid sinus are a rare surgical pathology. Cerebrospinal fluid leak from lateral recess of the sphenoid sinus is observed with a frequency of 7.7% among all leakafe of the skull base. The article presents 3 clinical cases of patients with spontaneous cerebrospinal fluid leak from lateral recess of the sphenoid sinus and surgical treatments by transsphenoidal and transpterygoid (transpterygoid) endoscopic approaches with various postoperative results. The plastic surgery success of CSF fistulas from lateral recess of the sphenoid sinus doesn`t depend on the type of endonasal surgical approach, but on the plastic quality and the preoperative level of CSF pressure.