Cerebrospinal Fluid Characteristics in Various Types of Encephalitis

Under normal circumstances, cerebrospinal fluid (CSF) is clear, colorless, and free of any clumps or particles. In cases of viral encephalitis, the CSF typically remains clear or may appear slightly cloudy. Protein levels are mildly elevated, while glucose levels remain within the normal range or are slightly increased. Chloride levels are generally unaffected. The white blood cell count is mildly elevated, predominantly consisting of lymphocytes.

Tuberculous Meningitis: Distinctive Cerebrospinal Fluid Features

One of the hallmark signs of tuberculous meningitis is the appearance of CSF that resembles cloudy or "frosted" glass. This condition is marked by a significant increase in protein levels, along with a notable decrease in both glucose and chloride concentrations. The cellular profile shows a rise in lymphocyte count. Importantly, microscopic examination or culture of the CSF may reveal the presence of Mycobacterium tuberculosis, which is crucial for diagnosis.

Findings in Purulent Meningitis

Key CSF Changes

In purulent meningitis, the cerebrospinal fluid appears visibly turbid and pus-like. There is a substantial increase in protein levels, coupled with a significant drop in glucose content. The white blood cell count is markedly elevated, primarily due to an influx of neutrophils. Additionally, bacterial cultures from the CSF typically yield positive results, aiding in the identification of the causative organism.

Japanese B Encephalitis: CSF Dynamics

Japanese B encephalitis presents with an increased total cell count in the CSF. During the early stages of the illness, neutrophils predominate. However, as the disease progresses, there is a shift toward a lymphocyte-predominant profile. These dynamic changes in cellular composition reflect the body's immune response over time.