Huntington's chorea

This code identifies Huntington's disease, a progressive neurodegenerative genetic disorder characterized by involuntary movements (chorea), cognitive decline, and psychiatric symptoms. It results from the degeneration of neurons in specific brain regions, primarily the basal ganglia. The onset typically occurs in middle age, leading to a gradual decline in motor and mental function.

Assign this code for documented cases of Huntington's disease, regardless of the stage of progression. It is appropriate when the patient's medical record clearly indicates a diagnosis of Huntington's chorea, often supported by genetic testing or a strong family history and characteristic clinical presentation. This code should be used for both initial diagnosis and subsequent encounters for management of the condition.

• Do not confuse with other forms of chorea (e.g., Sydenham's chorea, drug-induced chorea) which have distinct ICD-9 codes.
• Ensure documentation specifies "Huntington's" to differentiate from unspecified chorea.
• Consider sequencing this code as the primary diagnosis when the encounter is focused on the management or complications directly related to Huntington's disease.