Brain metabolic abnormalities during gait with freezing in Parkinson’s disease

International audienc

Resting-State Functional Connectivity in Frontostriatal and Posterior Cortical Subtypes in Parkinson's Disease-Mild Cognitive Impairment

International audienceBackgroundThe “dual syndrome hypothesis” distinguished two subtypes in mild cognitive impairment (MCI) in Parkinson's disease: frontostriatal, characterized by attentional and executive deficits; and posterior cortical, characterized by visuospatial, memory, and language deficits.ObjectiveThe aim was to identify resting-state functional modifications associated with these subtypes.MethodsNinety-five nondemented patients categorized as having normal cognition (n = 31), frontostriatal (n = 14), posterior cortical (n = 20), or mixed (n = 30) cognitive subtype had a 3 T resting-state functional magnetic resonance imaging scan. Twenty-four age-matched healthy controls (HCs) were also included. A group-level independent component analysis was performed to identify resting-state networks, and the selected components were subdivided into 564 cortical regions in addition to 26 basal ganglia regions. Global intra- and inter-network connectivity along with global and local efficiencies was compared between groups. The network-based statistics approach was used to identify connections significantly different between groups

Could conservative iron chelation lead to neuroprotection in amyotrophic lateral sclerosis?

Iron accumulation has been observed in mouse models and both sporadic and familial forms of Amyotrophic lateral sclerosis. Iron chelation could reduce iron accumulation and the related excess of oxidative stress in the motor pathways. However, classical iron chelation would induce systemic iron depletion. We assess the safety and efficacy of conservative iron chelation (i.e. chelation with low risk of iron depletion) in a murine preclinical model and pilot clinical trial. In Sod1G86R mice, deferiprone increased the mean life span as compared with placebo. The safety was good, without anemia after 12 months of deferiprone in the 23 ALS patients enrolled in the clinical trial. The decreases in the ALS Functional Rating Scale and the body mass index (BMI) were significantly smaller for the first 3 months of deferiprone treatment (30 mg/kg/day) than for the first treatment-free period. Iron levels in the cervical spinal cord, medulla oblongata and motor cortex (according to MRI), as well as cerebrospinal fluid levels of oxidative stress and neurofilament light chains were lower after deferiprone treatment. Our observation leads to the hypothesis that moderate iron chelation regimen that avoids changes in systemic iron levels may constitute a novel therapeutic modality of neuroprotection for ALS

Insuffisance cardiaque à fonction systolique altérée (analyse des prescriptions et recommandations à la sortie d'un service de court séjour gériatrique)

L'insuffisant cardiaque âgé doit pouvoir bénéficier, en l'absence de contre-indication, d'un inhibiteur de l'enzyme de conversion (IEC) et d'un béta-bloquant. Notre étude porte sur 50 patients avec insuffisance cardiaque à fonction systolique altérée hospitalisés dans un service de court séjour gériatrique, et entre dans le cadre d'une évaluation des pratiques professionnelles à l hôpital et en ville six mois après la sortie. Elle permet ainsi d'effectuer une analyse épidémiologique des insuffisants cardiaques âgés, d étudier les facteurs influant sur la prescription et de mettre à jour les faiblesses et points forts des pratiques hospitalières et des pratiques de ville, afin de proposer des axes d amélioration et des actions correctives. Notre étude montre en effet qu'il serait nécessaire d introduire ou d augmenter plus fréquemment les IEC, ainsi que d'utiliser de façon plus rigoureuse les béta-bloquants.NANTES-BU Médecine pharmacie (441092101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

What can we learn from fMRI capture of visual hallucinations in Parkinson’s disease?

Background: With disease progression, patients with Parkinson’s disease (PD) may havechronic visual hallucinations (VH). The mechanisms behind this invalidating non-motorsymptom remain largely unknown, namely because it is extremely difficult to capturehallucination events. This study aimed to describe the patterns of brain functional changeswhen VH occur in PD patients.Methods: Nine PD patients were enrolled because of their frequent and chronic VH (>10/day). Patients with severe cognitive decline (MMSE<18) were excluded. Patients werescanned during ON/OFF hallucinatory states and resting-state functional imaging (rs-fMRI)was performed. Data were analyzed in reference to the two-step method, which consists in:(i) a data-driven analysis of per-hallucinatory fMRI data, and (ii) selection of the componentsof interest based on a post-fMRI interview.Results: The phenomenology of VH ranged from visual spots to distorting faces. First, at theindividual level, several VH-related components of interest were identified and integrated ina second-level analysis. Using a random-effects self-organizing-group ICA, we evidencedincreased connectivity in visual networks concomitant to VH, encompassing V2, V3 and thefusiform gyri bilaterally. Interestingly, the stability of the default-mode network (DMN) wasfound positively correlated with VH severity (spearman’s rho = 0.77, p = 0.05).Conclusion: By using a method that does not need online self-report, we showed that VH inPD patients were associated with functional changes in associative visual cortices, possiblylinked with strengthened stability of resting-state networks

Anxiety in Parkinson's Disease Is Associated with Changes in Brain Structural Connectivity

BACKGROUND: Anxiety in Parkinson's disease (PD) has been associated with grey matter changes and functional changes in anxiety-related neuronal circuits. So far, no study has analyzed white matter (WM) changes in patients with PD and anxiety. OBJECTIVE: The aim of this study was to identify WM changes by comparing PD patients with and without anxiety, using diffusion-tensor imaging (DTI). METHODS: 108 non-demented PD patients with (n?=?31) and without (n?=?77) anxiety as defined by their score on the Parkinson Anxiety Scale participated. DTI was used to determine the fractional anisotropy (FA) and mean diffusivity (MD) in specific tracts within anxiety-related neuronal circuits. Mean FA and MD were compared between groups and correlated with the severity of anxiety adjusted by sex, center, Hoehn &amp; Yahr stage, levodopa equivalent daily dosage, and Hamilton depression rating scale. RESULTS: Compared to patients without anxiety, PD patients with anxiety showed lower FA within the striato-orbitofrontal, striato-cingulate, cingulate-limbic, and caudate-thalamic tracts; higher FA within the striato-limbic and accumbens-thalamic tracts; higher MD within the striato-thalamic tract and lower MD within the striato-limbic tract. CONCLUSIONS: Anxiety in PD is associated with microstructural alterations in anxiety-related neuronal circuits within the WM. This result reinforces the view that PD-related anxiety is linked to structural alteration within the anxiety-related brain circuits