Electrical stimulation of the globus pallidus internus in patients with primary generalized dystonia: long-term results.
OBJECTIVE
Primary generalized dystonia (PGD) is a medically refractory disease of the brain causing twisting or spasmodic movements and abnormal postures. In more than 30% of cases it is associated with the autosomal DYT1 mutation. Continuous electrical stimulation of the globus pallidus internus (GPi) has been used successfully in the treatment of PGD. The aim of this study was to examine the long-term efficacy and safety of deep brain stimulation (DBS) in the treatment of PGD in children and adults with and without the DYT1 mutation.


METHODS
Thirty-one patients with PGD were selected for surgery. Electrodes were bilaterally implanted under stereotactic guidance and connected to neurostimulators that were inserted subcutaneously. Efficacy was evaluated by comparing scores on the clinical and functional Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) before and after implantation. The efficacy of stimulation improved with time. After 2 years, compared with preoperative values, the mean (+/- standard deviation) clinical and functional BFMDRS scores had improved by 79 +/- 19% and 65 +/- 33%, respectively. At the 2-year follow-up examination the improvement was comparable in patients with and without the DYT1 mutation in both the functional (p = 0.12) and clinical (p = 0.33) scores. Children displayed greater improvements in the clinical score than adult patients (p = 0.04) at 2 years of follow up. In contrast, there was no significant difference in functional scores between children and adults (p = 0.95).


CONCLUSIONS
Electrical stimulation of the GPi is an effective, reversible, and adaptable treatment for PGD and should be considered for conditions refractory to pharmaceutical therapies.
Department of Neurosurgery, School of Medicine, University of Montpellier, France.
Philippe
P
Coubes
Laura
L
Cif
Hassan
H
El Fertit
Simone
S
Hemm
Nathalie
N
Vayssiere
Stephanie
S
Serrat
Marie Christine
MC
Picot
Sylvie
S
Tuffery
Mireille
M
Claustres
Bernard
B
Echenne
Philippe
P
Frerebeau
D000328:Adult; D020821:Dystonic Disorders / Q000503:physiopathology / Q000601:surgery*; D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D004567:Electrodes, Implanted; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D018832:Molecular Chaperones / Q000235:genetics; D019635:Neurosurgical Procedures / Q000295:instrumentation; D017354:Point Mutation / Q000235:genetics; D011187:Posture / Q000502:physiology; D012189:Retrospective Studies; D018911:Trinucleotide Repeats / Q000235:genetics
D018832:Molecular Chaperones; C108175:TOR1A protein, human