Atypical virus infection of central nervous system, unsp

This code signifies a central nervous system (CNS) infection caused by an atypical virus, where the specific viral agent is not identified or documented. It encompasses conditions like encephalitis, meningitis, or myelitis when the causative atypical virus is unknown.

Use this code when documentation clearly indicates an atypical viral CNS infection, but the specific type of virus (e.g., enterovirus, arbovirus, herpes simplex) has not been determined or is not specified. This is often an interim diagnosis while awaiting definitive lab results or when a specific viral etiology cannot be established.

• Avoid using this code if a specific atypical virus is identified; instead, code to the specific viral etiology.
• Always query the provider for more specificity if possible, especially if lab results are pending or available.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, followed by any associated neurological manifestations.