A81.9

Applicable To

• Prion diseases of the central nervous system NOS

Approximate Synonyms

• Prion disease

• Prion disease of central nervous system

• Slow viral central nervous system infection

• Slow virus infection of central nervous system

Clinical Information

• A group of genetic, infectious, or sporadic degenerative human and animal nervous system disorders associated with abnormal prions. These diseases are characterized by conversion of the normal prion protein to an abnormal configuration via a post-translational process. In humans, these conditions generally feature dementia; ataxia; and a fatal outcome. Pathologic features include a spongiform encephalopathy without evidence of inflammation. The older literature occasionally refers to these as unconventional slow virus diseases. from proc natl acad sci usa 1998 nov 10;95 23):13363-83)

• Any of various brain diseases in humans and animals in which areas of the brain slowly degenerate and take on a spongy appearance.

• Prion diseases, also termed transmissible spongiform encephalopathies tses), are a group of fatal neurodegenerative diseases that affect humans and a number of other animal species. The etiology of these diseases is thought to be associated with the conversion of a normal protein, prpc, into an infectious, pathogenic form, prpsc. The conversion is induced by prion infections for example, variant creutzfeldt-jakob disease vcjd), iatrogenic cjd, kuru), mutations familial cjd, gerstmann-straussler-scheinker syndrome, fatal familial insomnia ffi)) or unknown factors sporadic cjd scjd)), and is thought to occur after prpc has reached the plasma membrane or is re-internalized for degradation. The prpsc form shows greater protease resistance than prpc and accumulates in affected individuals, often in the form of extracellular plaques. Pathways that may lead to neuronal death comprise oxidative stress, regulated activation of complement, ubiquitin-proteasome and endosomal-lysosomal systems, synaptic alterations and dendritic atrophy, corticosteroid response, and endoplasmic reticulum stress. In addition, the conformational transition could lead to the lost of a beneficial activity of the natively folded protein, prpc.

Details

• A81.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.

• Short description: Atypical virus infection of central nervous system, unsp

• The 2023 edition of ICD-10-CM A81.9 became effective on October 1, 2022.

• This is the American ICD-10-CM version of A81.9 – other international versions of ICD-10 A81.9 may differ.