A dissociation between real and simulated movements in Parkinson's disease

Subcortical lesions have been simultaneously implicated in both real and simulated movement deficits. However, the analysis of the simulated opposition axis in precision grasping reveals that, in individuals with idiopathic bilateral Parkinson's disease motor imagery is impaired and that execution of overt movements is spared. This constitutes the first lesion observation congruent with the anatomical and functional dichotomy between real and simulated movements seen in experimental studies. These results underline the modality-specific nature of motor imagery and show that subcortical damage differentially impacts on motor activity

Simulated precision grasping in Parkinson’s Disease.

Subcortical lesions have been simultaneously implicated in both real and simulated movement deficits, suggesting that as with frontal le- sions, self action representation and programmation are the same process. We have analyzed the simulated precision grasping in subjects with idiopathic bilateral PD compared to a healthy control group. Re- sults showed that individuals with PD are impaired in the mental rep- resentation of a grasp orientation but are still capable of normally ex- ecuting this movement. These observations reveal that programmation and execution of movements is spared and that motor representation is selectively impaired. Thus, programmation of real acts and representa- tion of motor action are distinct processes

Dopaminergic innervation of the human subventricular zone: a comparison between Huntington’s chorea and Parkinson’s disease

The subventricular zone retains its neurogenic capacity throughout life and, as such, is often considered a potential source for endogenous repair in neurodegenerative disorders. Because dopamine is believed to stimulate adult neurogenesis, we looked for possible variations in the dopaminergic innervation of the subventricular zone between cases of Huntington’s chorea and Parkinson’s diseases. Antibodies against tyrosine hydroxylase (TH) and proliferating cell nuclear antigen (PCNA) were used as specific markers of dopaminergic axons and cell proliferating activity, respectively. The immunohistochemical approach was applied to postmortem tissue from 2 Parkinson’s disease cases, 4 Huntington’s disease cases, along with age-matched controls. The immunostaining was revealed with either diaminobenzidine or fluorescent-conjugated secondary antibodies. Optical density measurements were made along the entire dorso-ventral extent of the caudate nucleus. An intense TH+ zone was detected along the ventricular border of the caudate nucleus in Huntington’s disease cases, but not in patients with Parkinson’s disease or age-matched controls. This thin (287±38 µm) paraventricular zone was composed of numerous small and densely packed dopamine axon varicosities and overlapped the deep layers of the subventricular zone. Its immunoreactivity was 47±8% more intense than that of adjacent striatal areas. The dopamine innervation of the subventricular zone is strikingly massive in Huntington’s chorea compared to Parkinson’s disease, a finding that concurs with the marked increase in neurogenesis noted in the subventricular zone of Huntington’s disease patients. This finding suggests that dopamine plays a crucial role in mechanisms designed to compensate for the massive striatal neuronal losses that occur in Huntington’s disease

Intense dopamine innervation of the subventricular zone in Huntington’s disease

Dopamine exerts a robust promoting effect on adult neurogenesis. Here, we report the presence of an intense dopamine (tyrosine hydroxylase immunoreactive) zone along the ventricular border of the caudate nucleus in patients with Huntington’s disease, but not in age-matched controls. This thin (150–400 lm) paraventricular zone was composed of numerous small and densely packed dopamine axon varicosities and overlapped the deep layers of the subventricular zone. Immunoreactivity in the paraventricular zone was 50% higher than in adjacent striatal areas. This intense dopamine zone concurs with the striking increase of neurogenesis noted in the subventricular zone of Huntington’s disease patients and indicates that dopamine might play a crucial role in intrinsic mechanisms designed to compensate for the massive striatal neuronal losses that occur in Huntington’s diseas

Combined Omic Analyzes of Cerebral Thrombi: A New Molecular Approach to Identify Cardioembolic Stroke Origin

International audienceBackground and Purpose: The diagnosis of cardioembolic stroke can be challenging for patient management in secondary stroke prevention, particularly in the case of covert paroxysmal atrial fibrillation. The molecular composition of a cerebral thrombus is related to its origin. Therefore, proteomic and metabolomic analyses of the retrieved thrombotic material should allow the identification of biomarkers or signatures to improve the etiological diagnosis of stroke. Methods: In this pilot study, the proteome and metabolome of cerebral thrombi from atherothrombotic and cardioembolic stroke patients were studied according to ASCOD phenotyping (A: atherosclerosis; S: small-vessel disease; C: cardiac pathology; O: other causes; D: dissection), with the highest causality grade, from the ThrombiOMIC cohort (consecutive patients with stroke recanalized by mechanical thrombectomy in an acute phase). Proteomic and metabolomic results were used separately or combined, and the obtained omic signatures were compared with classical cardioembolic stroke predictors using pairwise comparisons of the area under receiver operating characteristics. Results: Among 59 patients of the ThrombiOMIC cohort, 34 patients with stroke showed a cardioembolic phenotype and 7 had an atherothrombotic phenotype. Two thousand four hundred fifty-six proteins and 5019 molecular features of the cerebral thrombi were identified using untargeted proteomic and metabolomic approaches, respectively. Area under receiver operating characteristics to predict the cardioembolic origin of stroke were calculated using the proteomic results (0.945 [95% CI, 0.871–1]), the metabolomic results (0.836 [95% CI, 0.714–0.958]), and combined signatures (0.996 [95% CI, 0.984–1]). The diagnostic performance of the combined signatures was significantly higher than that of classical predictors such as the plasmatic BNP (B-type natriuretic peptide) level (area under receiver operating characteristics, 0.803 [95% CI, 0.629–0.976]). Conclusions: The combined proteomic and metabolomic analyses of retrieved cerebral thrombi is a very promising molecular approach to predict the cardioembolic cause of stroke and to improve secondary stroke prevention strategies

Recommandations de la Société francophone de la sclérose en plaques « Vaccinations et sclérose en plaques » : mise à jour 2024

International audienceThe French Group for Recommendations for Multiple Sclerosis (France4MS) for the French MS Society (SFSEP) updated its 2019 recommendations on immunization for patients with multiple sclerosis (MS). This update includes the most recent available immunoreactive treatments and specific situations (pregnancy, childhood, elderly patients, travelers, and COVID-19). Physicians and patients should be aware of the updated recommendations for immunizations of patients with MS.Le groupe français pour les recommandations de la SFSEP a mis à jour les recommandations « Vaccinations et SEP » publiées en 2019. Cette mise à jour tient compte de la littérature récente, mais aussi de l’arrivée de nouvelles molécules, ou de situations particulières non abordées dans les précédentes recommandations (femmes enceintes, enfants, personnes âgées, voyageurs, COVID-19). Il est important que les médecins et les patients soient bien informés des mises à jours disponibles des recommandations vaccinales

Donepezil in Parkinson's disease dementia: A randomized, double-blind efficacy and safety study

Parkinson's disease dementia (PDD) is associated with cholinergic deficits. This report presents an efficacy and safety study of the acetylcholinesterase inhibitor donepezil hydrochloride in PDD. PDD patients (n = 550) were randomized to donepezil (5 or 10 mg) or placebo for 24 weeks. Coprimary end points were the Alzheimer's Disease Assessment Scalecognitive subscale (ADAS-cog) and Clinician's Interview-Based Impression of Change plus caregiver input (CIBIC+; global function). Secondary end points measured executive function, attention, activities of daily living (ADLs), and behavioral symptoms. Safety and tolerability were assessed. ADAS-cog mean changes from baseline to week 24 (end point) were not significant for donepezil in the intent-to-treat population by the predefined statistical model (difference from placebo: -1.45, P = .050, for 5 mg; -1.45, P = .076, for 10 mg). Alternative ADAS-cog analysis, removing the treatment-by-country interaction term from the model, revealed significant, dose-dependent benefit with donepezil (difference from placebo: -2.08, P = .002, for 5 mg; -3.31, P < .001, for 10 mg). The 10-mg group, but not the 5-mg group, had significantly better CIBIC+ scores compared with placebo (3.7 vs 3.9, P = .113, for 5 mg; 3.6 vs 3.9, P = .040, for 10 mg). Secondary end pointsMiniMental State Exam; DelisKaplan Executive Function System; Brief Test of Attention, representing cognitive functions particularly relevant to PDDshowed significant benefit for both donepezil doses (P = .007). There were no significant differences in ADLs or behavior. Adverse events were more common with donepezil but mostly mild/moderate in severity. Although the study did not achieve its predefined primary end points, it presents evidence suggesting that donepezil can improve cognition, executive function, and global status in PDD. Tolerability was consistent with the known safety profile of donepezil. (C) 2012 Movement Disorder Societ

La mort

Le sujet traité sous un angle résolument anthropologique, concerne l'Europe d'aujourd'hui : rituels funéraires des Tsiganes de Hongrie, photographies servant de médiation entre morts et vivants en Calabre, familiarisation des étudiants en médecine avec les cadavres, important taux de suicide chez les Vaqueiros des Asturies, autant d'études de cas sur les diverses façons de se représenter et d'affronter la mort