Long-Term Efficacy and Safety of Chronic Globus Pallidus Internus Stimulation in Different Types of Primary Dystonia

Background: Deep brain stimulation (DBS) of the globus pallidus
internus (GPi) offers a very promising therapy for medically
intractable dystonia. However, little is known about the long-term
benefit and safety of this procedure. We therefore performed a
retrospective long-term analysis of 18 patients (age 12-78 years)
suffering from primary generalized (9), segmental (6) or focal (3)
dystonia (minimum follow-up: 36 months). Methods: Outcome was
assessed using the Burke-Fahn-Marsden (BFM) scores (generalized
dystonia) and the Tsui score (focal/segmental dystonia). Follow-up
ranged between 37 and 90 months (mean 60 months). Results: Patients
with generalized dystonia showed a mean improvement in the BFM
movement score of 39.4% (range 0 68.8%), 42.5% (range -16.0 to
81.3%) and 46.8% (range-2.7 to 83.1%) at the 3- and 12-month, and
long-term follow-up, respectively. In focal/ segmental dystonia,
the mean reduction in the Tsui score was 36.8% (range 0-100%),
65.1% (range 16.7-100%) and 59.8% (range 16.7-100%) at the 3- and
12-month, and long-term follow-up, respectively. Local infections
were noted in 2 patients and hardware problems (electrode
dislocation and breakage of the extension cable) in 1 patient.
Conclusion: Our data showed Gpi-DBS to offer a very effective and
safe therapy for different kinds of primary dystonia, with a
significant long-term benefit in the majority of cases. Copyright
(c) 2008 S. Karger AG, Basel