Neurológia pre prax 1/2026
The importance of cerebrospinal fluid examination in the diagnosis and differential diagnosis of neuroinfections
Cerebrospinal fluid analysis represents a key diagnostic instrument in confirming and differentiating various forms of CNS infections due to its ability to reveal specific cytologic, biochemical and microbiological changes. In cases where CNS infection is suspected, a basic cerebrospinal fluid examination includes the enumeration of nucleated cells and erythrocytes, the differentiation of nucleated cells into mononuclear and polymorphonuclear cells, and, if applicable, a detailed qualitative analysis from a permanent cytological slide. Furthermore, the determination of total protein, glucose and lactate concentrations and the coefficient of energy balance (KEB) is essential. In cases where the differential diagnosis is subarachnoid haemorrhage, an additional spectrophotometric examination is recommended. Multiplex PCR is a useful technique for identifying the causative agent in both serous and purulent inflammation. In cases of bacterial or mycotic infections, microscopic and culture examinations are also necessary. Other examinations of the CSF include indirect diagnostics, such as the detection of an antibody response (e. g. in Central European tick-borne encephalitis) or, in selected diseases, the demonstration of intrathecal (IT) synthesis of specific antibodies. This test is particularly useful in the diagnosis of neuroborreliosis and neurosyphilis, and can also be used in suspected herpetic infections with EBV, HSV, VZV and CMV. However, it is important to note that confirmation of IT synthesis does not always indicate acute disease. Indeed, it may persist after a previous illness or be seen in a chronic inflammatory autoimmune process in the CNS. In the case of Lyme disease, the detection of the chemokine CXCL13 is also useful to support the diagnosis in cases where there is a negative IT synthesis at an early stage.
Keywords: CNS infections, cerebrospinal fluid (CSF), cell count, total protein, glucose, lactate, PCR, antibody index, KEB, CXCL13.
