Publications (3)37.42 Total impact
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Article: Non-motor dopamine withdrawal syndrome after surgery for Parkinson's disease: predictors and underlying mesolimbic denervation.
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ABSTRACT: Apathy has been reported to occur after subthalamic nucleus stimulation, a treatment of motor complications in advanced Parkinson's disease. We carried out a prospective study of the occurrence of apathy and associated symptoms, predictors and mechanisms in the year following subthalamic stimulation. Dopamine agonist drugs were discontinued immediately after surgery and levodopa was markedly reduced within 2 weeks. Apathy and depression were assessed monthly, using the Starkstein apathy scale and the Beck Depression Inventory. Dopamine agonists were re-introduced if patients developed apathy or depression. Preoperative non-motor fluctuations were evaluated using the Ardouin Scale. Depression, apathy and anxiety were evaluated both on and off levodopa. Analysis of predictors of apathy was performed using a Cox proportional hazard model. Twelve patients who developed apathy and a control group of 13 patients who did not underwent [11C]-raclopride positron emission tomography scanning before and after oral intake of methylphenidate. In 63 patients with Parkinson's disease treated with subthalamic stimulation, dopaminergic treatment was decreased by 82% after surgery. Apathy occurred after a mean of 4.7 (3.3-8.2) months in 34 patients and was reversible in half of these by the 12-month follow-up. Seventeen patients developed transient depression after 5.7 (4.7-9.3) months and these fell into the apathy group with one single exception. At baseline, fluctuations in depression, apathy and anxiety scores were greater in the group with apathy. Fluctuations in apathy, depression and anxiety ratings during a baseline levodopa challenge were also significant predictors of postoperative apathy in univariate analysis, but not motor and cognitive states or the level of reduction of dopaminergic medication. The multivariate model identified non-motor fluctuations in everyday life and anxiety score during the baseline levodopa challenge as two independent significant predictors of postoperative apathy. Without methylphenidate, [11C]-raclopride binding potential values were greater in apathetic patients bilaterally in the orbitofrontal, dorsolateral prefrontal, posterior cingulate and temporal cortices, left striatum and right amygdala, reflecting greater dopamine D2/D3 receptor density and/or reduced synaptic dopamine level in these areas. The variations of [11C]-raclopride binding potential values induced by methylphenidate were greater in non-apathetic patients in the left orbitofrontal cortex, dorsolateral prefrontal cortex, thalamus and internal globus pallidus and bilaterally in the anterior and posterior cingulate cortices, consistent with a more important capacity to release dopamine. Non-motor fluctuations are related to mesolimbic dopaminergic denervation. Apathy, depression and anxiety can occur after surgery as a delayed dopamine withdrawal syndrome. A varying extent of mesolimbic dopaminergic denervation and differences in dopaminergic treatment largely determine mood, anxiety and motivation in patients with Parkinson's disease, contributing to different non-motor phenotypes.Brain 03/2010; 133(Pt 4):1111-27. · 9.46 Impact Factor -
Article: Interruption of deep brain stimulation of the globus pallidus in primary generalized dystonia.
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ABSTRACT: Stimulation (DBS) of the globus pallidus (GP) is effective to treat generalized dystonia. Little is known about the evolution of dystonia in case of arrest after a long period of stimulation. This study describes the course of dystonia during a 48 hours period without stimulation followed by a 24 hours period after turning ON the stimulator. 14 patients with generalized dystonia treated with bilateral GP DBS for 3 years or more were recruited. Blinded video-based analysis was performed using Burke-Fahn-Marsden scale at (1) baseline (ON stimulation), (2) up to 48 hours after the stimulator was turned OFF, and (3) 24 hours after the stimulator was turned ON. 13 patients completed the 48 hours OFF-stimulation period. The dystonia movement score progressively worsened from 24.3 +/- 13.9 at baseline to 48.9 +/- 19.8 after 48 hours (P < 0.00001). The disability score also worsened from 4.4 +/- 1.2 at baseline to 5.7 +/- 1.5 after 48 hours without stimulation (P < 0.001). When the neurostimulator was turned ON, the dystonia scores returned to baseline level after 10 hours. The interruption of GP DBS in dystonia results in a progressive worsening which is rapidly reversible once the neurostimulator is turned ON.Movement Disorders 11/2009; 24(16):2363-9. · 4.51 Impact Factor -
Article: Bilateral pallidal deep brain stimulation for the treatment of patients with dystonia-choreoathetosis cerebral palsy: a prospective pilot study.
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ABSTRACT: 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. 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. 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]). 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. National PHRC; Cerebral Palsy Foundation: Fondation Motrice/APETREIMC; French INSERM Dystonia National Network; Medtronic.The Lancet Neurology 09/2009; 8(8):709-17. · 23.46 Impact Factor
