How is the diagnosis of chorea made?

Chorea is a movement disorder characterized by involuntary, purposeless movements of the limbs, trunk, and face. It can be caused by various underlying medical conditions, including:

- Huntington's disease: This is an inherited neurodegenerative disorder that causes progressive chorea and other movement abnormalities.

- Sydenham's chorea: This is a childhood movement disorder that occurs as part of rheumatic fever, an inflammatory condition that follows a streptococcal infection.

- Drug-induced chorea: Certain medications can cause chorea as a side effect, such as antipsychotics and stimulants.

- Other medical conditions: Chorea can also be associated with conditions like thyroid dysfunction, Wilson's disease, and certain infections.

The diagnosis of chorea involves:

1. Medical history: The doctor will ask about the individual's symptoms, including the nature of the involuntary movements, their frequency, and any associated neurological or medical problems.

2. Physical examination: This includes observing the individual's movements and assessing their coordination, reflexes, and muscle tone.

3. Neurological examination: This includes tests of cognitive function, speech, eye movements, and gait.

4. Imaging studies: Magnetic resonance imaging (MRI) or computed tomography (CT) scans of the brain may be ordered to identify structural abnormalities or lesions that could be causing the chorea.

5. Laboratory tests: Blood tests may be done to check for thyroid function, vitamin B12 levels, and markers of infections or other medical conditions that can cause chorea.

6. Genetic testing: In some cases, genetic testing may be recommended to confirm a diagnosis of Huntington's disease or other inherited movement disorders.

The specific diagnostic tests ordered will depend on the individual's symptoms and the suspected underlying cause of the chorea.