Mechanisms of body weight gain in parkinson patients after subthalamic stimulation: implication of changes in energy expenditure

Mechanisms of body weight gain in parkinson patients after subthalamic stimulation: implication of changes in energy expenditure. 57. Annual Meeting of the American Academy of Neurolog

Comparison between atlas based diagrams used for indirect STN targeting and STN templates determined directly on stereotactic MRI

International audienceObjective. Stereotactic determination of the subthalamic nucleus (STN) target is based on diagrams (indirect statistical coordinates relatively to anterior and posterior commissures AC, PC) or on direct MRI visualization. We aimed to compare both methods.Methods. We studied 30 STN in 15 parkinsonian patients operated on for bilateral electrode placement. STN, AC and PC were identified on stereotactic 1.5-Tesla MRI slices (stereotactic frame in place; T2 weighted). We outlined STN boundaries on coronal slices. We defined a lateral template (hexagonal shape; on the sagittal slice where STN was widest) then 3 frontal templates (quadrilateral shape) located on the anterior, the intermediate and the posterior borders of lateral STN template. We built Guiot’s (modified by Benabid et al.) and Talairach’s STN diagrams. We tested discordance, using paired means comparisons, on locations of centres between STN diagrams and templates, for both frontal and lateral views.Results. There were significant differences (p<0.05) between diagrams and templates in laterality, in ACPC direction and in dorso-ventral direction, except for the anterior frontal template in the dorso-ventral direction. Schematically the lateral template was in a more posterior and ventral position and the frontal templates were in a more medial position. Considering only the indirect method, the locations of centres on frontal and on lateral diagrams, in the dorso-ventral direction, were significantly different.Conclusions. A slight translation of diagrams on lateral view would probably allow a better correspondence with STN directly defined on MRI. The shape of diagram used on frontal view could also be modified

Mécanismes de la prise de poids chez le patient parkinsonien après stimulation sous-thalamique : implication des modifications de la dépense énergétique

Mécanismes de la prise de poids chez le patient parkinsonien après stimulation sous-thalamique : implication des modifications de la dépense énergétique. 24.Congrès de la Société Francophone de Nutrition Entérale et Parentérale (SFNEP

Deep Brain Stimulation for Parkinson’s Disease: Anatomical Location of Effective Contacts in the Sub Thalamic Area

International audienceThe location of effective contacts during deep brain stimulation (DBS) is still debated in particular in the sub thalamic area.Objectives:To localise on 1.5 T MRI, the effective contacts in patients successfully treated for Parkinson’s disease by bilateral DBS of the sub thalamic nucleus (STN).Material and methods:Ten patients with excellent clinical outcome were analysed. The surgical procedure was based on direct targeting of the nucleus (anatomic targeting without reference to internal landmarks). The effective contacts were determined during the first 6 months following the implantation, i.e. those given the best efficacy on the clinical symptoms (mean improvement rate 82.5%, range 75.8–94.1%). The contact locations were retrospectively projected on the stereotactic 1.5 T MRI (3 sets, orthogonal plans), i.e. with a stereotactic frame. For each patient, we have distinguished the right and the left hemisphere. The location of the effective contacts was directly studied by visual comparison, between the 1.5 T images and an in-house 4.7 T MRI anatomic reference. The membership for a given structure was determined using the results for each orthogonal, independent plan.Results:The effective contact were located within the STN in 4 cases, at the interface of the STN and the zona incerta (ZI) and/or the Forel’s field (FF) in 12 cases, at the interface between ZI and FF in 3 cases, at the interface between the STN and the substantia nigra in one case.Discussion:The dorsolateral part of the STN is usually considered as the target for DBS in Parkinson’s disease. We discuss the role of adjacent structures, especially ZI and FF, in the clinical benefit. A largest study, including 56 patients is already in progress to assess and to refine these results

Mechanisms of body weight gain in parkinsonian patients after subthalamic stimulation: Implication of changes in energy expenditure

Mechanisms of body weight gain in parkinsonian patients after subthalamic stimulation: Implication of changes in energy expenditure. 8. International Congress of Parkinson's Disease and Movement Disorder

Contribution of local field potential to subthalamic nucleus deep brain stimulation in Parkinson's disease

International audienceIntroduction: The subthalamic nucleus (STN) is the main target for deep brain stimulation (DBS) in Parkinson’s disease. We analyzed the relationships between magnetic resonance imaging (MRI) anatomy and electrophysiology (local field potential, LFP) done during surgery.Objectives: We hypothesized that the contribution of LFP to neuronal firing rate with detailed MRI anatomy should allow to explore finely anatomo-electrophysiological relationships and also to determine precisely functional surgical targets.Methods:Ten patients with Parkinson’s disease (5F; mean age: 62±4 years; 11±3 years disease duration) underwent bilateral STN DBS surgical procedure.Electrophysiology: 693 LFP recordings in MRI-outlined anatomical structures (Thalamus [Thal], Zona Incerta [ZI], Forel Field [Forel] and STN) were analyzed: Power spectral densities (PSD) from 0 to 100Hz; 1024 frequency values; Normalization: percent of total PSD; Calculation for delta (0-4 Hz), theta (4-7 Hz), alpha (7-13 Hz), beta (13-30 Hz), gamma (30-50 Hz, 50-100 Hz) frequency range. Non-parametric Kruskal-Wallis ANOVA tests were performed followed by pairwise comparisons with adjusted p-value.Results: Percentage of power spectral density for main physiological LFP frequency range was considered for thalamus, ZI, STN and Forel (Figure).Conclusions: This study suggests the interest of LFP to discriminate between structures in the subthalamic region using exploration electrode with patient at rest during DBS surgery. Another part of this study will consist in correlating extracellular neuronal activity and LFP, and analyzing modulations on LFP during voluntary movements of patients

Somatotopy in the GPi: analysis of motor side effects during intraoperative assessment in a Parkinsonian

International audienceObjective. A somatotopy inside the human globus pallidus (GP), based on intraoperative microelectrode-recordings during passive or active movement, and on clinical results of deep brain stimulation (DBS) in movement disorders, has been reported. We aimed to report a GP somatotopy, observed in one parkinsonian patient based on dystonic motor side effect assessment during acute stimulation, and related to MRI anatomy.Methods. A 68 year old parkinsonian (female, 16-year history; suffering mainly from limb and trunk dyskinesia) underwent bilateral stereotactic DBS surgery in internal GP (GPi) based on direct MRI targeting. We identified the different GP parts on T2-weighted coronal slices: external GP (GPe) and lateral and medial subdivisions of GPi (GPil, GPim). Controlateral dystonic movements were noted during acute intraoperative stimulation underlocal anaesthesia (1 or 2 mm step; mean current = 0.97 +/- 0.14 mA) along the distal 10 mm on 3 parallel tracts (2 mm distant; left hemisphere: central, lateral and medial; right hemisphere: central, anterior and lateral). On the 6 tracts (45 GP checkpoints), the involved body parts (face, upper and lower limbs) were matched with the anatomic structures. Postoperatively, chronic DBS dramatically improved dyskinesia (electrodes implanted on the central tracks).Results. GPe, GPil and GPim seemed to be characterized by a segregated body map. We found inside each structure a rostrocaudal organisation: face, superior part; upper limb, intermediate part; lower limb, inferior part.Conclusions. Motor side effect analysis is an interesting tool for somatotopic investigations. The GP somatotopy related to these clinical conditions has to be confirmed

Stimulation sous-thalamique dans la maladie de Parkinson sévère: Étude de la localisation des contacts effectifs

International audienceThe subthalamic nucleus (STN) is the main target of deep brain stimulation (DBS) treatment for severe idiopathic Parkinson's disease. But there is still no clear information on the location of the effective contacts (used during the chronic phase of stimulation). Our aim was to assess the anatomical structures of the subthalamic area (STA) involved during chronic DBS. Ten patients successfully treated were included. The surgical procedure was based on direct STN targeting (stereotactic MRI based) pondered by the acute effects of intraoperative stimulation. We used a formaldehyde-fixed human specimen to compare by matching MRI images obtained at 1.5 Tesla (performed in clinical stereotactic conditions) and at very high field at 4.7 Tesla. This allowed accurate analysis of the anatomy of the STA and retrospective precision of the location of the center of effective contacts which were located within the STN in 4 patients, at the interface between the STN and the ZI and/or FF in 13, at the interface between ZI and FF in 2 and between the STN and the substantia nigra in one. These results were consistent with the literature, revealing the implication of neighboring structures, especially the zona incerta and Forel's Field, in the clinical benefit.Le noyau sous-thalamique (NST) s’est imposé comme la cible de choix de la stimulation cérébrale profonde (SCP) dans la maladie de Parkinson idiopathique sévère. Toutefois, la position des contacts utilisés lors de la stimulation chronique (contacts effectifs) reste mal connue. Notre but était de préciser, au sein de la région sous-thalamique (RST), la topographie des contacts effectifs. Pour cela, nous avons réalisé en préalable un travail sur spécimen anatomique, par mise en correspondance d’images IRM à 1,5 Tesla (en conditions cliniques) et à très haut champ à 4,7 Tesla, explorant la RST. Nous avons ensuite étudié une série de 10 patients traités par DBS bilatérale avec un bon résultat clinique. L’implantation avait été réalisée en visée directe (repérage direct du STN sur IRM stéréotaxique) pondérée en fonction des effets de la stimulation aiguë per-opératoire. Nous avons revu a posteriori, en s’aidant de l’anatomie IRM très haut champ, la position du centre des contacts effectifs. Si certains contacts étaient placés à l’intérieur du NST (4 fois), la plupart se trouvaient à l’interface de ce dernier et de la zona incerta et/ou des champs de Forel (13 fois), à l’interface zona incerta et champs de Forel (2 fois) et à l’interface NST substance noire (1 fois). Ces résultats sont en accord avec la littérature. L’implication des structures voisines du NST dans le bénéfice clinique, en particulier la zona incerta et le champ de Forel, semble donc probable

Étude rétrospective de la localisation des contacts effectifs sous-thalamiques chez 53 parkinsoniens sévères : analyse des couples de contacts par une approche unifiée (droit-gauche) et indépendante (droit et gauche)

National audienceEn stimulation cérébrale profonde sous-thalamique pour maladie de Parkinson sévère, la localisation des contacts est souvent simplifiée, appelée stimulation chronique du noyau sous-thalamique (NST) ou STN DBS (Subthalamic Nucleus Deep Brain Stimulation). Nous avons fait l'hypothèse que l'analyse de la position des contacts par rapport au NST, permettrait de mieux comprendre les effets cliniques. Chez 53 patients (60,9 ans±7,4), 106 contacts effectifs ont été localisés par rapport au NST: longitudinalement, le long de l'axe antéro-postérieur, en position antérieure, intermédiaire et postérieur; transversalement, en position médiale, supérieure, latérale ou inférieure; et par rapport aux limites du NST, dedans, dehors, et à la frontière. Nous avons étudié les relations entre la position unifiée (droite-gauche) et les couples de contacts droit et gauche, et le score moteur UPDRS (Unified Parkinson's Disease Rating Scale) III global, la dysarthrie (UPDRS II et III, sous-scores, parole) et le piétinement (UPDRS II, sous-score, freezing), sans et avec dopa, sans et avec stimulation (chronique ou aiguë). L'analyse statistique a été réalisée avec des tests le plus souvent non paramétriques, l'erreur de type I était fixée à alpha = 0,05 (Statasoftware, version12; StataCorp, College Station, TX, USA). Nous n'avons pas trouvé de relation entre la position des contacts (unifiée ou couples droit et gauche) et l'amélioration du score moteur (UPDRS III global). La dysarthrie et le freezing étaient plus fréquents chez les patients avec des contacts unifiés en dehors du STN. De même, la dysarthrie était plus fréquente chez les patients qui avaient un contact en position postérieure, supérieure, en dehors et à gauche. La prise en compte de la position des contacts effectifs par rapport au noyau sous-thalamique semble utile pour comprendre des effets cliniques. Les résultats de cette étude pourraient être utiles pour le ciblage chirurgical lors de maladie de Parkinson sévère

Deep brain stimulation in routine clinical practice: monocentric study of the battery lifetime of different generations of neurostimulators

TalkInternational audienceRoutine clinical practice of Deep Brain Stimulation (DBS) enters a new era where battery-related events are challenging. The important number of primary implantations and replacements pushed industrials to develop new generations of devices. We aimed to analyze the battery lifetime of different kinds of non-rechargeable devices, manufactured by a single company (Medtronic, USA): the first generation of 4-contact neurostimulator for one DBS-lead (1 channel; Soletra®) and 8-contact neurostimulator for two DBS-leads (two channels of 4 contacts; Kinetra®); the second generation of advanced programming neurostimulator (Activa® PC, two channels of 8 contacts, and SC, 1 channel of 8 contacts). We retrospectively reviewed 281 consecutive patients operated on in a single institution (from 1995 to 2016): 584 surgeries for primary implantation or replacement of neurostimulator (infection and traumatic etiologies of battery replacement were excluded). The battery lifetime was defined as the period between the surgical implantation and the removal at battery depletion. Two hundred and eighty eight battery-lifetimes were analyzed in 157 patients suffering of Parkinson disease (n=129), essential tremor (n=19), dystonia (n=9). Exclusion criteria were: battery related, still operational (n=217); patient related, died before battery depletion (n=50); missing follow-up (n=3); and other diseases treated by DBS (n=2). Battery lifetime was analyzed using survival methods (univariate, Log-Rank test; multivariate, marginal cox model; two-sided tests) accounting for the following parameters: gender, neurological disease, age at the primary implantation, the UPDRS-score before DBS surgery, the deep brain target, battery model, mean voltage (low 4V), location of battery (abdominal or sub clavicular) and presence of an adapter for replacement of first generation (Kinetra or Soletra) by second generation model (Activa).Results: The battery lifetime was shorter in male (p=0.03) and young (p<0.001) patients suffering of essential tremor (p<0.001) and dystonia (p<0.001). High voltage reduced battery lifetime (p<0.001). The second generation device, Activa models, had shorter lifetime than first generation, Soletra and Kinetra (p<0.001). Replacement of battery decreased lifetime independently of models (p<0.001). Patient and disease characteristics, high voltage, second generation devices and replacement seem to shorten lifetime of battery