What are the characteristics of cerebrospinal fluid in tuberculous meningitis?

    In general, cerebrospinal fluid (CSF) examination of patients with tuberculous meningitis shows characteristic changes, mainly including elevated CSF pressure, abnormal CSF appearance, abnormal white blood cell count and classification, increased protein content with decreased glucose and chloride levels, and positive etiological detection. The specific analysis is as follows:

    1. Elevated CSF pressure: During lumbar puncture and pressure measurement, most patients are found to have CSF pressure significantly higher than the normal range. The increased pressure is mainly due to the invasion of the meninges by Mycobacterium tuberculosis, which triggers an inflammatory response, obstructs the CSF circulation pathway, and causes imbalance between CSF production and absorption, leading to elevated intracranial pressure.

    2. Abnormal CSF appearance: Normal CSF is colorless and transparent, while the CSF of patients with tuberculous meningitis often appears abnormal. It commonly presents as a "frosted glass" turbidity, meaning the CSF appears transparent but shows slight cloudiness when exposed to light, resembling the texture of frosted glass.

    3. Abnormal white blood cell count and classification: The white blood cell count in the CSF mildly to moderately increases, typically dominated by lymphocytes. This occurs because the meninges are stimulated by Mycobacterium tuberculosis, triggering an immune defense response. Lymphocytes accumulate in the meninges and CSF, participating in the inflammatory response, thereby significantly increasing the proportion of lymphocytes in the CSF.

    4. Elevated protein content with decreased glucose and chloride levels: CSF biochemical analysis shows increased protein levels, which is caused by increased vascular permeability due to meningeal inflammation, allowing plasma proteins to leak into the CSF.

    5. Positive etiological detection: Through CSF etiological examination, Mycobacterium tuberculosis can be detected in some patients. Commonly used detection methods include acid-fast staining of CSF smears. If acid-fast bacilli are observed under the microscope,

    Patients are advised to keep the puncture site clean and dry during CSF examination to avoid infection from contact with water. Adequate rest should be ensured in daily life to avoid excessive fatigue, and attention should be given to nutritional supplementation to support the body in fighting the disease and facilitating recovery.