Late-onset cerebellar ataxia

This code describes a form of hereditary ataxia characterized by progressive cerebellar dysfunction that manifests in adulthood, typically after the age of 20. Patients experience symptoms such as gait instability, incoordination, dysarthria, and nystagmus, which worsen over time. It is distinct from congenital or early-onset forms of cerebellar ataxia.

Use this code for patients diagnosed with a genetically determined cerebellar ataxia where the onset of symptoms occurred in adulthood. Documentation should clearly indicate the adult onset of cerebellar signs and symptoms, often supported by genetic testing confirming a specific ataxia subtype (e.g., SCA, Friedreich's ataxia with late onset). This code is appropriate when the specific type of late-onset cerebellar ataxia is not otherwise specified or if the documentation only indicates "late-onset cerebellar ataxia."

• Differentiate from G11.1 (Early-onset cerebellar ataxia) based on the age of symptom onset.
• If a more specific type of hereditary ataxia is documented (e.g., specific SCA type), use the more precise code from categories G11.1 or G11.8.
• Always review documentation for genetic testing results or a definitive clinical diagnosis of late-onset cerebellar ataxia.