Other atypical virus infections of central nervous system

This code signifies central nervous system (CNS) infections caused by atypical viruses not specified elsewhere. These are rare viral encephalopathies or myelopathies that do not fit into more specific categories like prion diseases or enteroviral infections. The infection can manifest with various neurological symptoms depending on the affected CNS region.

Use this code when documentation clearly indicates a viral CNS infection, but the specific atypical virus is identified and does not have a more precise ICD-10-CM code. This typically follows extensive diagnostic workup, including CSF analysis, viral cultures, or PCR, that confirms a viral etiology but excludes common or specifically coded viral agents.

• Ensure the documentation specifies "atypical virus" or a specific rare virus not otherwise classified, affecting the CNS.
• Do not use for unspecified viral CNS infections; instead, consider codes like G05.1 (Encephalitis, myelitis and encephalomyelitis in viral disease classified elsewhere).
• Always sequence this code after the underlying viral disease if it is known and has a separate code.