A81.9 is a billable ICD-10 code used to specify a medical diagnosis of atypical virus infection of central nervous system, unspecified. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.
Unspecified diagnosis codes like A81.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.
The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:
- Acquired prion disease
- Dementia due to infectious disease
- Dementia due to prion disease
- Familial Alzheimer-like prion disease
- Parkinsonism due to prion disease
- Prion disease
- Secondary tic disorder
- Slow viral central nervous system infection
- Tic disorder due to prion disease
Tabular List of Diseases and Injuries
The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to this diagnosis code:
Inclusion TermsInclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
- Prion diseases of the central nervous system NOS
Index to Diseases and Injuries References
The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for this diagnosis code are found in the injuries and diseases index:
Convert to ICD-9 Code
|Source ICD-10 Code||Target ICD-9 Code|
|A81.9||046.9 - Cns slow virus infec NOS|
The brain, spinal cord, and nerves make up the nervous system. Together they control all the workings of the body. When something goes wrong with a part of your nervous system, you can have trouble moving, speaking, swallowing, breathing, or learning. You can also have problems with your memory, senses, or mood.
There are more than 600 neurologic diseases. Major types include:
- Diseases caused by faulty genes, such as Huntington's disease and muscular dystrophy
- Problems with the way the nervous system develops, such as spina bifida
- Degenerative diseases, where nerve cells are damaged or die, such as Parkinson's disease and Alzheimer's disease
- Diseases of the blood vessels that supply the brain, such as stroke
- Injuries to the spinal cord and brain
- Seizure disorders, such as epilepsy
- Cancer, such as brain tumors
- infections, such as meningitis
[Learn More in MedlinePlus]
Viruses are very tiny germs. They are made of genetic material inside of a protein coating. Viruses cause familiar infectious diseases such as the common cold, flu and warts. They also cause severe illnesses such as HIV/AIDS, Ebola, and COVID-19.
Viruses are like hijackers. They invade living, normal cells and use those cells to multiply and produce other viruses like themselves. This can kill, damage, or change the cells and make you sick. Different viruses attack certain cells in your body such as your liver, respiratory system, or blood.
When you get a virus, you may not always get sick from it. Your immune system may be able to fight it off.
For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus. Antibiotics do not work for viral infections. There are antiviral medicines to treat some viral infections. Vaccines can help prevent you from getting many viral diseases.
[Learn More in MedlinePlus]
- FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
- FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
- FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
- FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
- FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
- FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
- FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
- FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)