Which finding would confirm a CSF leak?

Which finding would confirm a CSF leak?

• A. Elevated CSF protein
• B. WBC count
• C. Positive Gram stain
• D. Halo sign on dressing

Answer: (D)

A halo sign on the dressing is a reliable bedside clue for a CSF leak. When CSF drains onto a dressing that also has some blood, the CSF spreads outward and forms a clear ring around the central blood stain. This distinct halo helps distinguish CSF from other fluids. In contrast, findings like elevated CSF protein, an increased white blood cell count, or a positive Gram stain point to infection or inflammation in the CSF rather than a leak, so they don’t confirm a leak.

A halo sign on the dressing is a reliable bedside clue for a CSF leak. When CSF drains onto a dressing that also has some blood, the CSF spreads outward and forms a clear ring around the central blood stain. This distinct halo helps distinguish CSF from other fluids. In contrast, findings like elevated CSF protein, an increased white blood cell count, or a positive Gram stain point to infection or inflammation in the CSF rather than a leak, so they don’t confirm a leak.