Sequelae of viral encephalitis

This code identifies residual neurological deficits or chronic conditions that persist as a direct consequence of a past viral encephalitis infection. These sequelae can manifest as cognitive impairments, motor deficits, epilepsy, or behavioral changes, long after the acute phase of the encephalitis has resolved.

Apply this code when documentation clearly indicates a current condition is a long-term effect directly attributable to a previous episode of viral encephalitis. This is typically used for patients presenting with chronic neurological issues where the acute viral infection is no longer active but has left lasting damage.

• Always sequence this code after the specific neurological condition or symptom being treated (e.g., G40.409 for epilepsy due to viral encephalitis).
• Ensure documentation explicitly links the current condition to a prior viral encephalitis; avoid using for active or acute encephalitis.
• Do not use this code if the patient is still in the acute phase of viral encephalitis; instead, code the active encephalitis (e.g., G05.1).