Gerstmann-Straussler-Scheinker syndrome

This code identifies a rare, inherited neurodegenerative prion disease characterized by progressive ataxia, dementia, and dysarthria. It is a transmissible spongiform encephalopathy (TSE) resulting from abnormal prion protein accumulation in the brain. The disease typically manifests in mid-adulthood and progresses to severe neurological impairment and death.

Use this code for patients diagnosed with Gerstmann-Straussler-Scheinker (GSS) syndrome, confirmed through genetic testing for PRNP mutations or neuropathological findings. Documentation should clearly indicate a definitive diagnosis of GSS, distinguishing it from other prion diseases. This code is appropriate when the patient's clinical presentation and diagnostic workup align with the established criteria for GSS.

• Ensure documentation specifies "Gerstmann-Straussler-Scheinker syndrome" to differentiate from other prion diseases.
• Do not confuse with Creutzfeldt-Jakob disease (CJD) or fatal familial insomnia (FFI), which are distinct prion diseases with different ICD-10-CM codes.
• Sequence as a primary diagnosis when GSS is the reason for the encounter; code associated neurological manifestations or complications as secondary diagnoses.