A 26 year old woman complains of headache of 1 day duration that has been intensifying in severity over the last few hours. There is discomfort while turning her head and cannot tolerate bright lights. On examination, there is no papilloedema nor rashes. Kernig’s sign is negative. Lumbar puncture results reveal: elevated protein, normal glucose, and lymphocytosis. She is generally unwell but haemodynamically stable. What is the single most likely diagnosis?
A. Viral meningitis
B. Migraine
C. Aseptic meningitis
D. Bacterial meningitis
E. TB meningitis
Know the types of meningitis for PLAB 1 since it overlaps in quite a few topics on the exam (i.e. neurology, emergency, and infectious diseases). Pay particular attention to the lumbar puncture results to differentiate each. Kernig’s sign does not need to be present for it to be a diagnosis of meningitis. If you forget the lab results, look at the history: viral meningitis has less severe symptoms than bacterial meningitis which can progress rapidly and produce signs of septic shock. TB meningitis is more gradual with: fever, weight loss, headache with progression to focal deficit +/or altered consciousness. Presentation • Classic: headache, fever, photophobia, neck stiffness • Cranial palsies: CN III, IV, VI, VII Diagnosis Lumbar puncture (viral meningitis CSF):
• Normal or high CSF pressure • Increased lymphocytes • Elevated protein • Glucose normal
Treatment: • Regardless of whether meningitis is bacterial, viral, or TB as a cause – give antibiotics before performing CT brain and/or lumbar puncture • If no rash: IV cefotaxime or [IV ceftriaxone + IV vancomycin + IV ampicillin] • If raised intracranial pressure: give mannitol