Professional and Linguistic Assessments Board (PLAB) Practice Exam

High glucose levels in cerebrospinal fluid (CSF) are typically indicative of what condition?

1. Bacterial infection

2. Viral infection

3. Fungal infection

4. Autoimmune disorder

The correct answer is: Viral infection

High glucose levels in cerebrospinal fluid (CSF) are typically indicative of a viral infection. In cases of viral meningitis, the body's response usually includes an increase in glucose levels as the viral replication leads to an inflammatory response. This response stimulates the production of glucose, which is utilized by the brain and other cells for energy as they work to combat the infection. This pattern of elevated glucose levels contrasts with bacterial infections, where you would generally see low glucose concentrations due to the high metabolic activity of bacteria, which consume glucose. In fungal infections, glucose levels can also be low due to similar mechanisms of consumption and inflammation. Autoimmune disorders can present with various CSF findings, but changes often involve other markers such as proteins or specific inflammatory cells rather than glucose levels. Understanding these differences in CSF profiles is essential for diagnosing the underlying cause of meningitis or other central nervous system infections effectively.