Snapshot A 19-year-old male is brought to the emergency department by his college roommate due to confusion and difficulty with arousing from sleep. The patient reports severe generalized headache, neck stiffness, and muscle aches. Temperature is 102.2°F (39°C), blood pressure is 102/68 mmHg, pulse is 107/min, and respirations are 22/min. On physical exam, a petechial rash is distributed on the thorax and extremities. While supine, neck flexion lead to involuntary knee flexion. (Meningococcal meningitis) Introduction Inflammatory disease of the meninges Etiology (see the Microbiology of Meningitis topic ) aseptic (viral) bacterial fungal non-infectious (e.g., systemic erythematosus lupus) drug-induced Presentation Symptoms fever neck stiffness photophobia seizures Physical exam positive Kernig sign patient supine knee extension while hips are 90° flexed → resistance/pain positive Brudzinski sign patient supine passive neck flexion → involuntary knee flexion petechial rash may suggest Neisseria meningitidis infection Evaluation Lumbar puncture for CSF studies Cerebrospinal Fluid Analysis Test Normal Bacterial Viral Fungal/TB Opening pressure ≤ 20 cm H2O ↑ Normal or slightly ↑ ↑ Color Clear Cloudy Clear Cloudy Cell count 0-5 cells/µL ↑ (PMN) ↑ (Lymphocytes) ↑ (Lymphocytes) Protein < 45 mg/dL ↑ Slighty ↑ ↑ CSF:Serum glucose > 0.6 ↓ Normal ↓ Blood tests blood cultures complete blood cell count C-reactive protein Differential Lyme disease Neurosyphilis Drug-induced meningitis e.g., NSAIDs and amoxicillin Non-infectious mengitis e.g., systemic lupus erythematosus Stroke Treatment Aseptic (viral) meningitis herpes simplex virus and varicella-zoster virus acyclovir Bacterial meningitis when organism is unknown vancomycin ceftriaxone ampicillin add if > 50 years or immunocompromised add dexamethasone if suspected pneumococcal meningitis chemoprophylaxis for close contacts in meningococcal meningitis e.g., rifampin, ceftriaxone, and ciprofloxacin Prognosis, Prevention, and Complications Complications bacterial meningitis may lead to SIADH