Patients with generalized dystonia often require deep brain stimulation (DBS) for improvement in quality of life when medications have been found to be ineffective or difficult to tolerate.
In cervical dystonia and other types of focal dystonia, botulinum toxin (Botox) injections are often beneficial, but in some patients the dystonia is too severe for adequate benefit from medical treatment. These patients can enjoy significant improvements in quality of life and recovery of function with DBS.
Patients with dystonia that are most likely to have a good outcome from DBS exhibit the following characteristics:
- Disabling dystonia
- Incomplete response to medications
- Younger patients (<21 years old)
- Shorter duration of symptoms (<15 years)
- Absence of fixed deformities or contractures
- DYT1, DYT6, or DYT11 positive
- Primary dystonia (not caused by an underlying disease)
- Absence of dementia or severe depression
- Normal MRI
- Good medical health
- Realistic expectations
Please note that patients who do not meet all the above criteria may still have dramatic benefit, therefore consultation with our team is useful to make specific recommendations.
Potential benefits of DBS
Studies of DBS for dystonia show a broader range of benefit of DBS compared to DBS for PD or ET. On average, patients with primary / genetic dystonia have about 50% reduction in their symptoms. However, around 20% of patients implanted may have very little benefit, whereas some patients may experience a larger degree of improvement, up to 80-90% reduction in symptoms and signs of dystonia. Some patients are able to reduce medications with DBS but the majority continue to take some medication or continue to have Botox injections.
Potential risks of DBS
Post-operative headache and pain are possible but typically resolves gradually a few weeks after the procedure. Neck pain is also possible in the short term. Infection of the leads, extension or battery is very low risk and our surgical team does their utmost to prevent this. Hemorrhage is extremely low risk but when it occurs may lead to stroke-like symptoms. Most frequently, hemorrhage does not result in permanent complications. Lead fracture or migration, also very low risk, may require repeat surgery.
Problems with speech, language and mood; muscle tightness, slurred speech and vision symptoms can be related to the stimulation and thus can usually be reduced or eliminated by adjusting the stimulation.