9.1.1.1 Acute headache attributed to bacterial meningitis or meningoencephalitis

Diagnostic criteria:
A. Headache fulfilling criteria for 9.1.1 Headache attributed to bacterial meningitis or meningoencephalitis, and criterion C below
B. Bacterial meningitis or meningoencephalitis remains active or has recently resolved
C. Headache has been present for <3 months.