How dystonia is classified
Dystonia can be described in different ways. Specialists classify dystonia based on when it begins, which body parts are affected, how symptoms change over time, and what causes it.
Usually, the age when symptoms first appear helps predict if they'll spread. When dystonia starts at a younger age, it’s more likely to affect multiple areas of the body. If it begins later in adulthood, the symptoms often stay in one place and remain more manageable.
How dystonia is distributed across the body helps determine the type:
- Focal dystonia: Symptoms are in one body part or one muscle group, like the neck or hand
- Segmental dystonia: The condition involves two or more body regions next to each other
- Multifocal dystonia: Symptoms affect two or more unconnected body regions
- Hemidystonia: The condition affects the arm and leg on the same side of the body
- Generalized dystonia: Most or all of the body is affected, including the torso
Understanding how symptoms evolve over time can help providers diagnose the type of dystonia. Symptoms might:
- Stay the same (static)
- Get worse over time (progressive)
- Happen only during certain tasks, like writing or playing an instrument
- Occur only at specific times of day
Caused-based categories describe why dystonia occurs:
- Nervous system issues: Sometimes, brain scans show injuries or structural changes that cause movements
- Medication-related: Certain medications for psychiatric conditions can trigger symptoms
- Genetics: You might have inherited a gene change from a parent, or a change may have happened on its own during your life
- Unknown causes: When a specific trigger can't be found, it's called idiopathic dystonia