Dystonia - Diagnosing dystonia

Diagnosing dystonia isn't straightforward. It involves using a stepwise approach that starts by identifying the precise nature and specific features of your movement disorders.

The specialist will then try to identify which type of dystonia classification your movement disorders fall into, taking into consideration a number of factors including:

• how old you were when your symptoms started
• the order in which your symptoms developed
• the speed at which the condition is progressing
• the results of initial tests and investigations

It's important to confirm whether you have primary or secondary dystonia to help determine the type of treatment you need.

In primary dystonia, muscle spasms are the only symptom and there's no other associated condition. Secondary dystonia is caused by an underlying health condition, injury or some other type of damage.

If you have the typical signs of late-onset focal dystonia, you may not need to have specific investigations. However, you may need to have a series of tests and examinations to confirm whether you have primary or secondary dystonia. These tests are described below.

• Your recent medical and family history will be discussed - for example, whether you've recently had a head injury, or whether you have a relative with dystonia.
• Urine and blood tests - to check how well your organs, such as your liver, are functioning and whether you have an infection or high levels of toxins in your body. 
• Genetic testing - a DNA sample can be taken from your blood and checked for the abnormal genes associated with some types of dystonia; genetic testing can also confirm whether or not your dystonia is caused by a genetic condition, such as Huntington's disease.
• A magnetic resonance imaging (MRI) scan - can check whether there's any damage to your brain, or whether you have a condition that's affecting your brain, such as a tumour.

If you have early-onset dystonia, you may also be given a course of medication called levodopa. If your symptoms suddenly improve after taking levodopa, a confident diagnosis of dopa-responsive dystonia can be made.