Jean-Luc Houeto

Subthalamic nucleus stimulation in severe obsessive-compulsive disorder.

BACKGROUNDnSevere, refractory obsessive-compulsive disorder (OCD) is a disabling condition. Stimulation of the subthalamic nucleus, a procedure that is already validated for the treatment of movement disorders, has been proposed as a therapeutic option.nnnMETHODSnIn this 10-month, crossover, double-blind, multicenter study assessing the efficacy and safety of stimulation of the subthalamic nucleus, we randomly assigned eight patients with highly refractory OCD to undergo active stimulation of the subthalamic nucleus followed by sham stimulation and eight to undergo sham stimulation followed by active stimulation. The primary outcome measure was the severity of OCD, as assessed by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), at the end of two 3-month periods. General psychopathologic findings, functioning, and tolerance were assessed with the use of standardized psychiatric scales, the Global Assessment of Functioning (GAF) scale, and neuropsychological tests.nnnRESULTSnAfter active stimulation of the subthalamic nucleus, the Y-BOCS score (on a scale from 0 to 40, with lower scores indicating less severe symptoms) was significantly lower than the score after sham stimulation (mean [+/-SD], 19+/-8 vs. 28+/-7; P=0.01), and the GAF score (on a scale from 1 to 90, with higher scores indicating higher levels of functioning) was significantly higher (56+/-14 vs. 43+/-8, P=0.005). The ratings of neuropsychological measures, depression, and anxiety were not modified by stimulation. There were 15 serious adverse events overall, including 1 intracerebral hemorrhage and 2 infections; there were also 23 nonserious adverse events.nnnCONCLUSIONSnThese preliminary findings suggest that stimulation of the subthalamic nucleus may reduce the symptoms of severe forms of OCD but is associated with a substantial risk of serious adverse events. (ClinicalTrials.gov number, NCT00169377.)

Deep brain stimulation: Neuropsychological and neuropsychiatric issues

Parkinsons disease (PD) is a neurodegenerative disorder characterized by motor, cognitive, neuropsychiatric, autonomic, and other nonmotor symptoms. The efficacy of deep brain stimulation (DBS) for the motor symptoms of advanced PD is well established. However, the effects of DBS on the cognitive and neuropsychiatric symptoms are less clear. The neuropsychiatric aspects of DBS for PD have recently been of considerable clinical and pathophysiological interest. As a companion to the preoperative and postoperative sections of the DBS consensus articles, this article reviews the published literature on the cognitive and neuropsychiatric aspects of DBS for PD. The majority of the observed neuropsychiatric symptoms are transient, treatable, and potentially preventable. Outcome studies, methodological issues, pathophysiology, and preoperative and postoperative management of the cognitive and neuropsychiatric aspects and complications of DBS for PD are discussed.

Bilateral, pallidal, deep-brain stimulation in primary generalised dystonia: a prospective 3 year follow-up study

BACKGROUNDnWe have previously reported the efficacy and safety of bilateral pallidal stimulation for primary generalised dystonia in a prospective, controlled, multicentre study with 1 year of follow-up. Although long-term results have been reported by other groups, no controlled assessment of motor and non-motor results is available. In this prospective multicentre 3 year follow-up study, involving the same patients as those enrolled in the 1 year follow-up study, we assessed the effect of bilateral pallidal stimulation on motor impairment, disability, quality of life, cognitive performance, and mood.nnnMETHODSnWe studied 22 patients with primary generalised dystonia after 3 years of bilateral pallidal stimulation. We compared outcome at 3 years with their status preoperatively and after 1 year of treatment. Standardised video recordings were scored by an independent expert. Data were analysed on an intention-to-treat basis.nnnFINDINGSnMotor improvement observed at 1 year (51%) was maintained at 3 years (58%). The improvement in quality of life (SF-36 questionnaire) was similar to that observed at 1 year. Relative to baseline and to the 1 year assessment, cognition and mood were unchanged 3 years after surgery, but slight improvements were noted in concept formation, reasoning, and executive functions. Pallidal stimulation was stopped bilaterally in three patients because of lack of improvement, technical dysfunction, and infection, and unilaterally in two patients because of electrode breakage and stimulation-induced contracture. No permanent adverse effects were observed.nnnINTERPRETATIONnBilateral pallidal stimulation provides sustained motor benefit after 3 years. Mild long-term improvements in quality of life and attention were also observed.

Compulsions, Parkinson's disease, and stimulation

Pathophysiological models suggest that obsessive compulsive disorder (OCD) might be associated with dysfunctions in cortico-striato-pallido-thalamo-cortical neuronal circuits. We implanted subthalamic electrodes to alleviate parkinsonian symptoms in two patients who had Parkinsons disease and a history of severe OCD. Parkinsonian disability improved postoperatively in both patients, and 2 weeks after the procedure, their compulsions had disappeared and obsessive symptoms improved (58% improvement for patient 1 on the Yale-Brown obsessive compulsive scale, 64% for patient 2). The improvements in these two patients suggest that high-frequency stimulation could improve function in the subcortical-limbic circuitry in patients with severe OCD.

Neurosurgery at an earlier stage of Parkinson disease: a randomized, controlled trial.

Background: Stimulation of the subthalamic nucleus is an effective treatment for advanced Parkinson disease (PD) and is currently performed after a mean disease duration of 14 years, when severe motor complications have resulted in marked loss of quality of life. We examined whether surgery at an early stage would maintain quality of life as well as improve motor function. Methods: Twenty patients with PD of short duration (time elapsed since first symptom ± SD: 6.8 ± 1.0 years) with mild to moderate motor signs (Unified Parkinsons Disease Rating Scale III “off” medication: 29 ± 12) who responded well to levodopa treatment were included in pairs, matched for age, duration and severity of disease, and impairment in socioprofessional functioning. Patients were prospectively randomized to undergo bilateral subthalamic nucleus stimulation (n = 10) or receive optimized medical treatment (n = 10). Parkinsonian motor scores, quality of life, cognition, and psychiatric morbidity were assessed at inclusion and at 6, 12, and 18 months after randomization. Results: Quality of life was improved by 24% in surgical and 0% in nonsurgical patients (p < 0.05). After 18 months, the severity of parkinsonian motor signs “off” medication, levodopa-induced motor complications, and daily levodopa dose were reduced by 69%, 83%, and 57% in operated patients and increased by 29%, 15%, and 12% in the group with medical treatment only (p < 0.001). Adverse events were mild or transient, and overall psychiatric morbidity and anxiety improved in the surgical group. Conclusions: Subthalamic nucleus stimulation should be considered a therapeutic option early in the course of Parkinson disease.

Internal Pallidal and Thalamic Stimulation in Patients With Tourette Syndrome

BACKGROUNDnTourette syndrome (TS) is thought to result from dysfunction of the associative-limbic territories of the basal ganglia, and patients with severe symptoms of TS respond poorly to medication. High-frequency stimulation has recently been applied to patients with TS in open studies using the centromedian-parafascicular complex (CM-Pf) of the thalamus, the internal globus pallidus (GPi), or the anterior limb of the internal capsule as the principal target.nnnOBJECTIVEnTo report the effect of high-frequency stimulation of the CM-Pf and/or the GPi, 2 associative-limbic relays of the basal ganglia, in patients with TS.nnnDESIGNnControlled, double-blind, randomized crossover study.nnnSETTINGnMedical research.nnnPATIENTSnThree patients with severe and medically refractory TS.nnnINTERVENTIONnBilateral placement of stimulating electrodes in the CM-Pf (associative-limbic part of the thalamus) and the GPi (ventromedial part).nnnMAIN OUTCOME MEASURESnEffects of thalamic, pallidal, simultaneous thalamic and pallidal, and sham stimulation on neurologic, neuropsychological, and psychiatric symptoms.nnnRESULTSnA dramatic improvement on the Yale Global Tic Severity Scale was obtained with bilateral stimulation of the GPi (reduction in tic severity of 65%, 96%, and 74% in patients 1, 2, and 3, respectively). Bilateral stimulation of the CM-Pf produced a 64%, 30%, and 40% reduction in tic severity, respectively. The association of thalamic and pallidal stimulation showed no further reduction in tic severity (60%, 43%, and 76%), whereas motor symptoms recurred during the sham condition. No neuropsychological, psychiatric, or other long-term adverse effect was observed.nnnCONCLUSIONSnHigh-frequency stimulation of the associative-limbic relay within the basal ganglia circuitry may be an effective treatment of patients with TS, thus heightening the hypothesis of a dysfunction in these structures in the pathophysiologic mechanism of the disorder.

Parkinson's disease with camptocormia

Background: Camptocormia is defined as an abnormal flexion of the trunk that appears when standing or walking and disappears in the supine position. The origin of the disorder is unknown, but it is usually attributed either to a primary or a secondary paravertebral muscle myopathy or a motor neurone disorder. Camptocormia is also observed in a minority of patients with parkinsonism. Objective: To characterise the clinical and electrophysiological features of camptocormia and parkinsonian symptoms in patients with Parkinson’s disease and camptocormia compared with patients with Parkinson’s disease without camptocormia. Methods: Patients with parkinsonism and camptocormia (excluding patients with multiple system atrophy) prospectively underwent a multidisciplinary clinical (neurological, neuropsychological, psychological, rheumatological) and neurophysiological (electromyogram, ocular movement recording) examination and were compared with age-matched patients with Parkinson’s disease without camptocormia. Results: The camptocormia developed after 8.5 (SD 5.3) years of parkinsonism, responded poorly to levodopa treatment (20%) and displayed features consistent with axial dystonia. Patients with camptocormia were characterised by prominent levodopa-unresponsive axial symptoms (ie, axial rigidity, gait disorder and postural instability), along with a tendency for greater error in the antisaccade paradigm. Conclusion: We suggest that (1) the salient features of parkinsonism observed in patients with camptocormia are likely to represent a specific form of Parkinson’s disease and camptocormia is an axial dystonia and (2) both camptocormia and parkinsonism in these patients might result from additional, non-dopaminergic neuronal dysfunction in the basal ganglia.

Methylphenidate for gait hypokinesia and freezing in patients with Parkinson's disease undergoing subthalamic stimulation: a multicentre, parallel, randomised, placebo-controlled trial

BACKGROUNDnDespite optimum medical management, many patients with Parkinsons disease are incapacitated by gait disorders including freezing of gait. We aimed to assess whether methylphenidate--through its combined action on dopamine and noradrenaline reuptake--would improve gait disorders and freezing of gate in patients with advanced Parkinsons disease without dementia who also received subthalamic nucleus stimulation.nnnMETHODSnThis multicentre, parallel, double-blind, placebo-controlled, randomised trial was done in 13 movement disorders departments in France between October, 2009, and December, 2011. Eligible patients were younger than 80 years and had Parkinsons disease, severe gait disorders, and freezing of gate despite optimised treatment of motor fluctuations with dopaminergic drugs and subthalamic stimulation. We randomly assigned patients (1:1 with a computer random-number generator in blocks of four) to receive methylphenidate (1 mg/kg per day) or placebo capsules for 90 days. Patients, their carers, study staff, investigators, and data analysts were masked to treatment allocation. To control for confounding effects of levodopa we assessed patients under standardised conditions with an acute levodopa challenge. Our primary outcome was a change in the number of steps during the stand-walk-sit (SWS) test without levodopa. We compared the respective mean numbers of steps at day 90 in the methylphenidate and placebo groups in a covariance analysis and adjusted for baseline differences. This trial is registered with ClinicalTrials.gov, number NCT00914095.nnnFINDINGSnWe screened 81 patients and randomly assigned 35 to receive methylphenidate and 34 to receive placebo. 33 patients in the methylphenidate group and 32 patients in the placebo group completed the study. Efficacy outcomes were assessed in the patients who completed the study. Compared with patients in the placebo group (median 33 steps [IQR 26-45]), the patients in the methylphenidate group made fewer steps at 90 days (31 [26-42], F((1, 62))=6·1, p=0·017, adjusted size effect 0·61). Adverse events were analysed in all randomly assigned patients. There were significantly more adverse events in the methylphenidate group compared with placebo. Patients on methylphenidate had a significant increase in heart rate (mean 3·6 [SD 7·2] beats per min) and decrease in weight (mean 2·2 [SD 1·8] kg) compared with the placebo group.nnnINTERPRETATIONnMethylphenidate improved gait hypokinesia and freezing in patients with advanced Parkinsons disease receiving subthalamic nucleus stimulation. Methylphenidate represents a therapeutic option in the treatment of gait disorders at the advanced stage of Parkinsons disease. The long term risk-benefit balance should be further studied.nnnFUNDINGnFrench Ministry of Health and Novartis Pharma.

Long-term effects of pallidal or subthalamic deep brain stimulation on quality of life in Parkinson's disease

We assessed the effects of deep brain stimulation of the subthalamic nucleus (STN‐DBS) or internal pallidum (GPi‐DBS) on health‐related quality of life (HrQoL) in patients with advanced Parkinsons disease participating in a previously reported multicenter trial. Sickness Impact Profile (SIP) questionnaires were available for analysis in a subgroup of n = 20/20 patients with GPi‐DBS and n = 45/49 patients with STN‐DBS at baseline, 6 and 36 months. The SIP provides a physical dimension and a psychosocial dimension sum score and 12 category scores: Alertness/Intellectual Behavior (AIB), Ambulation (A), Body Care and Movement (BCM), Communication (C), Eating (E), Emotional Behavior (EB), Home Management (HM), Mobility (M), Recreation and Pastimes (RP), Sleep and Rest (SR), Social Interaction (SI), and Work (W). Motor functioning was assessed by means of the Unified Parkinsons Disease Rating Scale and diaries. At 6 months significant improvements in off‐period motor symptoms and activities of daily living were paralleled by significant reductions in the total, physical, and psychosocial SIP score in both treatment groups. At 3 years, sustained improvements were observed in the physical dimension score, BCM, E, M, RP after STN‐DBS and M, SI after GPi‐DBS. All other SIP subscores approached baseline values, but were still the same or better (except C) whereas motor functioning remained stable after 36 months. STN‐DBS and GPi‐DBS led to significant early improvements in HrQoL. Despite sustained motor improvements many of these initial benefits were lost after 3 years. This may reflect either progression of the disease or adaptive changes in the subjective perception of health‐related wellbeing over time.

Selecting deep brain stimulation or infusion therapies in advanced Parkinson's disease: an evidence-based review

Motor complications in Parkinson’s disease (PD) result from the short half-life and irregular plasma fluctuations of oral levodopa. When strategies of providing more continuous dopaminergic stimulation by adjusting oral medication fail, patients may be candidates for one of three device-aided therapies: deep brain stimulation (DBS), continuous subcutaneous apomorphine infusion, or continuous duodenal/jejunal levodopa/carbidopa pump infusion (DLI). These therapies differ in their invasiveness, side-effect profile, and the need for nursing care. So far, very few comparative studies have evaluated the efficacy of the three device-aided therapies for specific motor problems in advanced PD. As a result, neurologists currently lack guidance as to which therapy could be most appropriate for a particular PD patient. A group of experts knowledgeable in all three therapies reviewed the currently available literature for each treatment and identified variables of clinical relevance for choosing one of the three options such as type of motor problems, age, and cognitive and psychiatric status. For each scenario, pragmatic and (if available) evidence-based recommendations are provided as to which patients could be candidates for either DBS, DLI, or subcutaneous apomorphine.