BACKGROUND: Cerebral palsy (CP) with dystonia-choreoathetosis is a common cause 
of disability in children and in adults, and responds poorly to medical 
treatment. Bilateral pallidal deep brain stimulation (BP-DBS) of the globus 
pallidus internus (GPi) is an effective treatment for primary dystonia, but the 
effect of this reversible surgical procedure on dystonia-choreoathetosis CP, 
which is a subtype of secondary dystonia, is unknown. Our aim was to test the 
effectiveness of BP-DBS in adults with dystonia-choreoathetosis CP.
METHODS: We did a multicentre prospective pilot study of BP-DBS in 13 adults 
with dystonia-choreoathetosis CP who had no cognitive impairment, little 
spasticity, and only slight abnormalities of the basal ganglia on MRI. The 
primary endpoint was change in the severity of dystonia-choreoathetosis after 1 
year of neurostimulation, as assessed with the Burke-Fahn-Marsden dystonia 
rating scale. The accuracy of surgical targeting to the GPi was assessed masked 
to the results of neurostimulation. Analysis was by intention to treat.
FINDINGS: The mean Burke-Fahn-Marsden dystonia rating scale movement score 
improved from 44.2 (SD 21.1) before surgery to 34.7 (21.9) at 1 year 
post-operatively (p=0.009; mean improvement 24.4 [21.1]%, 95% CI 11.6-37.1). 
Functional disability, pain, and mental health-related quality of life were 
significantly improved. There was no worsening of cognition or mood. Adverse 
events were related to stimulation (arrest of the stimulator in one patient, and 
an adjustment to the current intensity in four patients). The optimum 
therapeutic target was the posterolateroventral region of the GPi. Little 
improvement was seen when the neurostimulation diffused to adjacent structures 
(mainly to the globus pallidus externus [GPe]).
INTERPRETATION: Bilateral pallidal neurostimulation could be an effective 
treatment option for patients with dystonia-choreoathetosis CP. However, given 
the heterogeneity of motor outcomes and the small sample size, results should be 
interpreted with caution. The optimum placement of the leads seemed to be a 
crucial, but not exclusive, factor that could affect a good outcome.
FUNDING: National PHRC; Cerebral Palsy Foundation: Fondation Motrice/APETREIMC; 
French INSERM Dystonia National Network; Medtronic.