Damianos E Sakas1, Athanassios Leonardos2, Efstathios Boviatsis1, Stergios Gatzonis3, Ioannis Panourias1, Pantelis Stathis3, Lampis C Stavrinou4. 1. Unit of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of Athens Medical School, Athens, Greece; "Petros S. Kokkalis" Hellenic Center for Neurosurgical Research, Athens, Greece. 2. "Petros S. Kokkalis" Hellenic Center for Neurosurgical Research, Athens, Greece. 3. Unit of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of Athens Medical School, Athens, Greece. 4. Unit of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of Athens Medical School, Athens, Greece; "Petros S. Kokkalis" Hellenic Center for Neurosurgical Research, Athens, Greece. Electronic address: mplam@hotmail.com.
Abstract
OBJECTIVE: To evaluate bilateral constant-current globus pallidus internus (GPi) deep brain stimulation using an 8-contact lead. METHODS: This prospective, open-label, single-center pilot study of 10 patients assessed the feasibility of delivering bilaterally constant-current GPi deep brain stimulation with a novel 8-channel lead to treat primary dystonia using standard scales as outcome measures. RESULTS: Patients included 4 men and 6 women with a mean age of 35.8 years ± 9.2 (range, 27-49 years). Mean age of onset was 18.5 years ± 9.1 (range, 8-35 years), and mean disease duration was 17.3 years (range, 7-27 years). All had primary dystonia (8 generalized dystonia, 1 segmental dystonia, 1 focal dystonia). The primary variable was determined as 50% reduction in dystonia symptoms from baseline to the 6-month follow-up, as defined by the Burke-Fahn-Marsden Dystonia Rating Scale. Six patients (60.0%) achieved >50% reduction in Burke-Fahn-Marsden Dystonia Rating Scale score and were classified as responders at the 6-month follow-up. Five of these 6 responders (83.3%) sustained that response through the assessment at the end of the first year. Constant-current stimulation was associated with significant improvement in pain and quality of life in all patients. Nearly 84% of the overall improvement occurred by the end of first month after stimulation onset, documenting an early response to treatment. Axial symptoms responded the best. CONCLUSIONS: Constant-current GPi deep brain stimulation proved safe and efficacious for treatment of primary dystonia. Motor scores improved by 54%, mostly within the first month. No phenotype-specific stimulation could be achieved, despite the capability of the new lead to stimulate specific loci within the GPi.
OBJECTIVE: To evaluate bilateral constant-current globus pallidus internus (GPi) deep brain stimulation using an 8-contact lead. METHODS: This prospective, open-label, single-center pilot study of 10 patients assessed the feasibility of delivering bilaterally constant-current GPi deep brain stimulation with a novel 8-channel lead to treat primary dystonia using standard scales as outcome measures. RESULTS:Patients included 4 men and 6 women with a mean age of 35.8 years ± 9.2 (range, 27-49 years). Mean age of onset was 18.5 years ± 9.1 (range, 8-35 years), and mean disease duration was 17.3 years (range, 7-27 years). All had primary dystonia (8 generalized dystonia, 1 segmental dystonia, 1 focal dystonia). The primary variable was determined as 50% reduction in dystonia symptoms from baseline to the 6-month follow-up, as defined by the Burke-Fahn-Marsden Dystonia Rating Scale. Six patients (60.0%) achieved >50% reduction in Burke-Fahn-Marsden Dystonia Rating Scale score and were classified as responders at the 6-month follow-up. Five of these 6 responders (83.3%) sustained that response through the assessment at the end of the first year. Constant-current stimulation was associated with significant improvement in pain and quality of life in all patients. Nearly 84% of the overall improvement occurred by the end of first month after stimulation onset, documenting an early response to treatment. Axial symptoms responded the best. CONCLUSIONS: Constant-current GPi deep brain stimulation proved safe and efficacious for treatment of primary dystonia. Motor scores improved by 54%, mostly within the first month. No phenotype-specific stimulation could be achieved, despite the capability of the new lead to stimulate specific loci within the GPi.