Congratulations to Drs.Long-term Outcomes with Rescue Target Deep Brain Stimulation in Patients with Dystonia” in the April supplement of Neurology.
Objective: Determine the long-term outcomes of rescue target deep brain stimulation (DBS) surgery in dystonia.
Background: Globus pallidus internus (GPi) and subthalamic nucleus (STN) are effective DBS targets for treatment of medication refractory dystonia, however the range of clinical improvements can be large. We offer a rescue target option to select patients exhibiting suboptimal DBS dystonia outcomes.
Design/Methods: We retrospectively identified among 102 dystonia DBS patients 8 cases of rescue target DBS who were followed for 3+ years following a rescue procedure. We tracked the Unified Dystonia Rating Scale (UDRS) scores for these patients before, after the initial DBS, and after the rescue DBS surgery. These cases were matched with 8 dystonia DBS patients without rescue leads based on disease duration, age, dystonia phenotype, initial DBS target, length of follow-up and pre-DBS UDRS scores.
Results: The rescue DBS cohort included 3 cervical and 5 generalized dystonia patients (mean age 53.2 ± 17.6 years; mean disease duration 16.8 ± 7.0 years). At a mean duration of 3.8 ± 2.4 years after initial bilateral GPi DBS, 7 patients received rescue lead STN DBS (5 bilateral, 2 unilateral); 1 patient received bilateral STN then bilateral GPi DBS. In the DBS cohort without rescue leads, UDRS scores improved by 48% (p = 0.03) at 3.8 ± 2.4 years with no further significant improvement at the last follow-up. In the cohort with rescue leads, UDRS scores initially only improved by 25% (p = 0.08) at 3.8 ± 2.4 years; rescue lead placement provided an additional 22.9% improvement. There was a total improvement of 47% (p = 0.01) at 3+ years after rescue DBS (9.5 ± 3.1 years after initial DBS).
Conclusions: Rescue target DBS can potentially be an effective treatment with sustained long-term benefits in this cohort. This procedure should be considered earlier for patients with suboptimal initial DBS outcomes.