Viral Meningitis

Diagnose Meningitis on PE with tests:
Kernig: flex thigh and knee to 90 degrees. Wont be able to fully extend knee.
Bruzinski (1) Neck: curling neck painful and elicits thigh flexion. (2) cheek: pressing cheek elicits elbow flexion. (3) Symphyseal: pubic pressure elicits thigh flexion and abduction.

Diagnose Meningitis gold with Brain MRI

Diagnose Viral vs. Bacterial vs. Fungal with Lumbar Puncture.

Viral: elevated protein (norm: 15-45)
Bacterial: reduced glucose (norm: 50-75)
Fungal: elevated lymphocytes

Causes: Often fecal-oral spread, usually hematogenous. (sometimes resp)

85% caused by enteroviruses: Echovirus, Coxsackie A, B, assoc: rash, pharyngitis, pericrditis, pleurodynia

Also, Echoviruses 70, 71. May cause GBS = Guillain Barre

5% Arboviruses: St. Louis Encephalitis, West Nile, although encephalitis more common.

Also, Mumps causes 10-20% of VM cases in unvaccinated populations.

4% of cases are Herpes viruses. Acyclovir early tx can help. Most often HSV-2

5-10% of HIV+ pts get viral meningitis.

Tx of viral meningitis: analgesics w Acyclovir 750 IV q8 x 14 d just in case it's a Herpes virus. Otherwise self limiting.

Other causes of "aseptic" meningitis include TB-, Mycoplasma-, Fungal- and Lyme Dz-caused.