After observing positive Kernig or Brudzinski signs, which diagnostic step is indicated?

• A. CT scan
• B. ECG
• C. Blood culture
• D. CSF analysis for diagnosis

Answer: (D)

Positive Kernig and Brudzinski signs point to meningitis, an inflammatory or infectious process involving the meninges. The best way to confirm the diagnosis and guide treatment is to obtain cerebrospinal fluid through a lumbar puncture and analyze it. CSF analysis provides opening pressure, cell count with differential, protein, glucose, and results from Gram stain and culture, which help distinguish bacterial from viral meningitis and identify the causative organism to tailor antibiotics and management.

Imaging like a CT scan may be considered before performing a lumbar puncture if there are signs suggesting increased intracranial pressure or mass effect, but it is not the primary diagnostic step for meningitis. Blood cultures can be helpful as an adjunct, but the definitive diagnosis comes from the CSF analysis.