Pallidal deep brain stimulation is effective, and improves quality of life in primary segmental and generalized dystonia

Background –  Dystonia is one of the most prevalent movement disorders, and may lead to abnormal postures, pain, significant disability and social isolation if not well treated. In widespread segmental or generalized dystonia efficient treatment options were lacking until the recent introduction of deep brain stimulation of the internal globus pallidus (pallidal DBS).
Methods –  The first case series and single-blinded controlled study showed promising results regarding the effect of pallidal DBS on dystonic movements, pain and disability, but the impact of this treatment on health-related quality of life (HRQoL) remained uncertain. Then, as part of the first randomized, and sham stimulation-controlled trial performed by the DBS for Dystonia Study Group, HRQoL was evaluated using the Short Form-36 Health Survey (SF-36) at baseline, after the 3 months sham-controlled phase, and after 6 months of continuous pallidal DBS, in 40 patients with severe primary segmental or generalized dystonia.
Results –  The 3-month sham-stimulation controlled phase resulted in significant improvement of dystonic movements, pain and disability in the active stimulation group, and four of the eight SF-36 domain scores also improved significantly compared with the sham-stimulated group. After 6 months of active stimulation in all patients, significant improvement in all eight SF-36 domains was observed, with comparable improvement in the segmental and generalized dystonia groups.
Conclusion –  Convincing evidence has been obtained that pallidal DBS effectively reduces dystonia-related symptoms, and markedly improves HRQoL in patients suffering from otherwise intractable, primary segmental or generalized dystonia, thus providing new opportunities for this patient group.