Chronic meningitis

This code represents a persistent inflammation of the meninges, the membranes surrounding the brain and spinal cord, lasting for at least four weeks. Unlike acute meningitis, chronic meningitis often has a more insidious onset and prolonged course, frequently associated with underlying infectious (e.g., fungal, mycobacterial) or non-infectious causes.

Assign this code when documentation clearly indicates a diagnosis of chronic meningitis. This diagnosis is typically supported by cerebrospinal fluid analysis showing persistent inflammation, neuroimaging findings, and clinical symptoms such as chronic headache, fever, and neurological deficits. Use this code when the specific etiology of the chronic meningitis is either unknown or not separately coded.

• Do not use this code for acute or subacute meningitis; refer to codes within G00-G02 for those conditions.
• Always code the underlying cause of the chronic meningitis first, if known and documented (e.g., fungal infection, tuberculosis).
• Ensure documentation specifies "chronic" to differentiate from other forms of meningitis.