2025 ICD-10-CM code A81.89
Other atypical virus infections of the central nervous system.
Medical necessity for this code is established by the documentation of clinical signs, symptoms, and diagnostic findings that support the diagnosis of an atypical viral infection of the CNS.The documentation should also demonstrate the impact of the condition on the patient's function and the need for medical intervention.
Clinicians should consider additional codes to specify any associated dementia, behavioral disturbances, mood disturbances, or psychotic disturbances.Diagnosis may involve laboratory tests of blood and cerebrospinal fluid (CSF), MRI of the brain, electroencephalogram (EEG), and spinal tap. Treatment focuses on symptom management, and patient education may include preventive measures like vaccinations.
- Certain infectious and parasitic diseases (A00-B99)
- Viral and prion infections of the central nervous system (A80-A89)
In simple words: This code refers to an uncommon type of viral infection that affects the brain and spinal cord.It's used when the specific virus causing the infection isn't covered by a more precise code. These infections can cause various problems with thinking, behavior, and physical function.
This code describes atypical viral infections affecting the central nervous system (CNS), excluding those specifically identified by other codes within the same category.These infections are typically subacute or chronic and involve the brain and spinal cord. They can manifest with a range of neurological and cognitive symptoms.
Example 1: A patient presents with progressive cognitive decline, personality changes, and seizures.After ruling out other causes, testing reveals an atypical viral infection of the CNS, and A81.89 is used to document the diagnosis., A patient with a history of encephalitis experiences ongoing neurological issues.Standard tests do not identify a specific viral cause, but clinical findings suggest an atypical viral infection, warranting the use of A81.89., A patient develops subacute cognitive impairment, motor difficulties, and behavioral changes.Diagnostic workup suggests a viral etiology, and in the absence of a more specific diagnosis, the atypical viral infection code A81.89 is assigned.
Documentation should include details of clinical presentation, neurological examination findings, results of laboratory tests (including CSF analysis and antibody testing), imaging studies (MRI, EEG), and any procedures performed (e.g., spinal tap).The rationale for diagnosing an atypical viral infection should also be documented, including the exclusion of other potential causes.
- Specialties:Infectious Disease, Neurology, Neuropsychiatry
- Place of Service:Inpatient Hospital, On Campus-Outpatient Hospital,Office