Focal dystonia is dystonia that affects only one part of the body. The most common forms are cervical dystonia (neck), blepharospasm (eyelids), oromandibular dystonia (jaw and mouth), laryngeal dystonia (voice) and task-specific limb dystonia such as writer’s cramp. It usually begins in adulthood and, unlike childhood dystonia, rarely spreads to the whole body.
Botulinum toxin injections are the first-line treatment for most focal dystonias.[1] When injections stop working well, or when the dystonia affects muscles that are hard to inject, deep brain stimulation is the next step. The best evidence for DBS in focal dystonia is in cervical dystonia, where a pooled analysis of 208 patients found a 58.8% average improvement on the standard rating scale.[2]
Types of focal dystonia
| Form | Body region | What patients notice |
|---|---|---|
| Cervical dystonia (spasmodic torticollis) | Neck | Head turns, tilts, pulls forward or back; neck pain; jerky head tremor |
| Blepharospasm | Eyelids | Frequent blinking, forced eye closure, functional blindness in severe cases |
| Oromandibular dystonia | Jaw, mouth, tongue | Jaw clenching or opening, tongue pushing, difficulty chewing and speaking |
| Laryngeal dystonia (spasmodic dysphonia) | Vocal cords | Strained, strangled or breathy voice |
| Writer’s cramp, musician’s dystonia | Hand and arm | Cramping or curling of fingers during one specific task |
| Foot dystonia | Foot | Foot turning in, toes curling, often when walking |
When blepharospasm and oromandibular dystonia occur together, the condition is called Meige syndrome. Technically this is segmental rather than focal, because two neighbouring regions are involved.
Why does focal dystonia happen?
In most adults no cause is found (idiopathic dystonia). Researchers think it results from abnormal processing in the circuits linking the basal ganglia, thalamus, cerebellum and cortex, and from loss of normal “surround inhibition” in the motor system. Repetitive, highly skilled use of a body part, as in musicians, writers or athletes, can trigger task-specific forms in people who are predisposed.
How is focal dystonia treated?
Treatment is chosen by region. The full approach is described on treatment for focal dystonia.
- Botulinum toxin is first-line for cervical dystonia and blepharospasm, with good evidence also in other focal forms.[1]
- Physiotherapy and sensory-motor retraining help many patients, especially in cervical and task-specific dystonia.
- Oral medications are used less in adults because the benefit is modest and side effects are common.
- Deep brain stimulation is used when the dystonia is disabling and injections fail. It has strong evidence in cervical dystonia, including a sham-controlled randomized trial,[3] and growing evidence in Meige syndrome, including a randomized double-blind trial.[4]
When should someone with focal dystonia think about DBS?
- Botulinum toxin no longer gives enough relief, or the effect wears off too fast between injections.
- The muscles involved are deep or hard to inject, as in some jaw and neck patterns.
- The dystonia causes disabling pain, inability to work, drive, read or eat.
- The dystonia has spread to neighbouring regions.
Frequently asked questions
Can focal dystonia be cured?
There is no cure, but symptoms can be controlled well. Botulinum toxin and, in selected patients, DBS reduce the movements and pain significantly.
Is DBS used for writer’s cramp?
Rarely. Task-specific hand dystonia is usually treated with injections and retraining. Thalamic surgery has been used in a small number of severe cases in specialised centers, but the evidence is much smaller than for cervical dystonia.
Is DBS used for spasmodic dysphonia?
DBS for isolated laryngeal dystonia is still being studied and is not a standard treatment. Voice symptoms can improve when they are part of a wider dystonia treated with DBS.
Sources
- Simpson DM, Hallett M, Ashman EJ, et al. Practice guideline update summary: Botulinum neurotoxin for the treatment of blepharospasm, cervical dystonia, adult spasticity, and headache. Neurology. 2016;86(19):1818–1826. Source
- Tsuboi T, Wong JK, Almeida L, et al. A pooled meta-analysis of GPi and STN deep brain stimulation outcomes for cervical dystonia. J Neurol. 2020;267(5):1278–1290. doi:10.1007/s00415-020-09703-9 Source
- Volkmann J, Mueller J, Deuschl G, et al. Pallidal neurostimulation in patients with medication-refractory cervical dystonia: a randomised, sham-controlled trial. Lancet Neurol. 2014;13(9):875–884. Source
- Globus pallidus internus versus subthalamic nucleus deep brain stimulation for Meige syndrome: a randomized controlled, double-blind, multicenter trial. J Neurosurg. Published online 2026. Source