44 research outputs found
A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability
AIM
To evaluate a standardised MRI acquisition protocol and a new image rating scale for disease severity in patients with progressive supranuclear palsy (PSP) and multiple systems atrophy (MSA) in a large multicentre study.
METHODS
The MRI protocol consisted of two-dimensional sagittal and axial T1, axial PD, and axial and coronal T2 weighted acquisitions. The 32 item ordinal scale evaluated abnormalities within the basal ganglia and posterior fossa, blind to diagnosis. Among 760 patients in the study population (PSP = 362, MSA = 398), 627 had per protocol images (PSP = 297, MSA = 330). Intra-rater (n = 60) and inter-rater (n = 555) reliability were assessed through Cohen's statistic, and scale structure through principal component analysis (PCA) (n = 441). Internal consistency and reliability were checked. Discriminant and predictive validity of extracted factors and total scores were tested for disease severity as per clinical diagnosis.
RESULTS
Intra-rater and inter-rater reliability were acceptable for 25 (78%) of the items scored (℠0.41). PCA revealed four meaningful clusters of covarying parameters (factor (F) F1: brainstem and cerebellum; F2: midbrain; F3: putamen; F4: other basal ganglia) with good to excellent internal consistency (Cronbach α 0.75-0.93) and moderate to excellent reliability (intraclass coefficient: F1: 0.92; F2: 0.79; F3: 0.71; F4: 0.49). The total score significantly discriminated for disease severity or diagnosis; factorial scores differentially discriminated for disease severity according to diagnosis (PSP: F1-F2; MSA: F2-F3). The total score was significantly related to survival in PSP (p<0.0007) or MSA (p<0.0005), indicating good predictive validity.
CONCLUSIONS
The scale is suitable for use in the context of multicentre studies and can reliably and consistently measure MRI abnormalities in PSP and MSA. Clinical Trial Registration Number The study protocol was filed in the open clinical trial registry (http://www.clinicaltrials.gov) with ID No NCT00211224
Role of Basal Ganglia Circuits in Resisting Interference by Distracters: A swLORETA Study
BACKGROUND: The selection of task-relevant information requires both the focalization of attention on the task and resistance to interference from irrelevant stimuli. Both mechanisms rely on a dorsal frontoparietal network, while focalization additionally involves a ventral frontoparietal network. The role of subcortical structures in attention is less clear, despite the fact that the striatum interacts significantly with the frontal cortex via frontostriatal loops. One means of investigating the basal ganglia's contributions to attention is to examine the features of P300 components (i.e. amplitude, latency, and generators) in patients with basal ganglia damage (such as in Parkinson's disease (PD), in which attention is often impaired). Three-stimulus oddball paradigms can be used to study distracter-elicited and target-elicited P300 subcomponents. METHODOLOGY/PRINCIPAL FINDINGS: In order to compare distracter- and target-elicited P300 components, high-density (128-channel) electroencephalograms were recorded during a three-stimulus visual oddball paradigm in 15 patients with early PD and 15 matched healthy controls. For each subject, the P300 sources were localized using standardized weighted low-resolution electromagnetic tomography (swLORETA). Comparative analyses (one-sample and two-sample t-tests) were performed using SPM5Âź software. The swLORETA analyses showed that PD patients displayed fewer dorsolateral prefrontal (DLPF) distracter-P300 generators but no significant differences in target-elicited P300 sources; this suggests dysfunction of the DLPF cortex when the executive frontostriatal loop is disrupted by basal ganglia damage. CONCLUSIONS/SIGNIFICANCE: Our results suggest that the cortical attention frontoparietal networks (mainly the dorsal one) are modulated by the basal ganglia. Disruption of this network in PD impairs resistance to distracters, which results in attention disorders
Deficit in decoding emotional facial expression in Parkinson's disease
International audienc
Les enjeux de la loi Léonetti : participation des patients atteints de sclérose latérale amyotrophique à une discussion anticipée sur la réanimation respiratoire et les soins de fin de vie
Par respect du principe dâautonomie, les experts rĂ©unis en confĂ©rence de consensus recommandent de discuter de façon anticipĂ©e avec le patient atteint de sclĂ©rose latĂ©rale amyotrophique (SLA) du traitement de la dĂ©faillance respiratoire terminale (accompagner le dĂ©cĂšs par des soins palliatifs ou mettre en place une trachĂ©otomie pour une supplĂ©ance ventilatoire de survie). La loi Leonetti inscrit un droit pour le patient de refuser une trachĂ©otomie sâil la considĂšre dĂ©raisonnable et prescrit aux mĂ©decins de tenir compte des directives anticipĂ©es sur le traitement de la dĂ©faillance respiratoire terminale quâaura donnĂ© la personne avant son incapacitĂ© Ă communiquer. Deux Ă©cueils sont Ă Ă©viter : que la visĂ©e de la relation mĂ©decin/patient soit lâobtention de ces directives anticipĂ©es et que la vulnĂ©rabilitĂ© du patient, avec ses ambivalences possibles, ne soit pas reconnue. Notre Ă©tude a portĂ© sur 35 patients atteints de SLA pour lesquels la question anticipĂ©e dâune rĂ©animation ou de soins palliatifs de fin de vie a pu ĂȘtre posĂ©e. Si la majoritĂ© des patients ont demandĂ© Ă en ĂȘtre informĂ©, 48 % nâont jamais pu anticiper. Seulement 20 % ont exprimĂ© des directives anticipĂ©es. Ces rĂ©sultats montrent que la discussion est dĂ©licate et conduit Ă nous interroger sur la dimension Ă©thique du concept dâautonomie, au-delĂ de sa formulation principliste : ne peut-on envisager lâincapacitĂ© de se confronter Ă la question existentielle de la mort possible ? Plus quâun exercice de respect de lâautonomie de la personne, il sâagit ici dâun exercice de responsabilitĂ© mĂ©dicale.// In accordance with the principle of personal autonomy, expert consensus statements on amyotrophic lateral sclerosis (ALS) recommend early engagement with terminal-phase patients on the type of symptomatic treatment to be administered in the event of respiratory failure, since decompensation progresses too rapidly to allow time for a discussion. The French Parliamentary Act on Patientsâ Rights and End-of-Life Care (dated 22 April 2005) grants individuals the right to refuse unreasonable treatment and obliges physicians to take account of any prior instructions given by a person before he/she became incapable of communicating. The provision of prior instructions is a very reassuring situation for the physician: the autonomous patient indicates his or her choice of end-of-life care. However, there are two pitfalls which must be avoided: (i) holding a discussion for the sole purpose of obtaining prior instructions and (ii) not acknowledging the patientâs vulnerability. The present study dealt with 35 ALS patients for whom the question of either intensive care or palliative end-of-life care remained open. Even though the great majority of these individuals were keen to know their exact state of health, 48% refused to consider this circumstance and only 20% expressed prior instructions. These results prompted us to question the ethical dimension of the concept of autonomy beyond its founding formulation: can one envisage an incapacity to confront oneself with the existential question of possible death? In 80% of cases, the physician will have to take a care decision in the absence of any prior instructions from the patient. This amounts to more than respecting a personâs autonomy and involves exercising medical responsibility
Memantine for patients with Parkinson's disease dementia or dementia with Lewy bodies: a randomised, double-blind, placebo-controlled trial
Background: Previous studies have suggested that patients with Lewy-body-related dementias might benefit from treatment with the N-methyl D-aspartate receptor antagonist memantine, but further data are needed. Therefore, the efficacy and safety of memantine were investigated in patients with mild to moderate Parkinson's disease dementia (PDD) or dementia with Lewy bodies (DLB). Methods: Patients (â„50 years of age) with mild to moderate PDD or DLB were recruited from 30 specialist centres in Austria, France, Germany, the UK, Greece, Italy, Spain, and Turkey. They were randomly assigned to placebo or memantine (20 mg per day) according to a computer-generated list. Patients and all physicians who had contact with them were masked to treatment assignment. No primary endpoint was defined. Safety analyses were done for all patients who took at least one dose of memantine or placebo, and efficacy analyses were done for all patients who had at least one valid postbaseline assessment. This trial is registered with ClinicalTrials.gov, number NCT00855686. Findings: Of the 199 patients randomly assigned to treatment, 34 with DLB and 62 with PDD were given memantine, and 41 with DLB and 58 with PDD were given placebo. 159 (80%) patients completed the study: 80 in the memantine group and 79 in the placebo group. 93 patients treated with memantine and 97 patients treated with placebo were included in the efficacy analysis. At week 24, patients with DLB who received memantine showed greater improvement according to Alzheimer's disease cooperative study (ADCS)-clinical global impression of change scores than did those who received placebo (mean change from baseline 3·3 vs 3·9, respectively, difference -0·6 [95% CI -1·2 to -0·1]; p=0·023). No significant differences were noted between the two treatments in patients with PDD (3·6 with memantine vs 3·8 with placebo, -0·1 [-0·6 to 0·3]; p=0·576) or in the total population (3·5 with memantine vs 3·8 with placebo, -0·3 [-0·7 to 0·1]; p=0·120). Neuropsychiatric-inventory scores showed significantly greater improvement in the memantine group than in the placebo group (-4·3 vs 1·7, respectively, -5·9 [-11·6 to -0·2]; p=0·041) in patients with DLB, but not in those with PDD (-1·6 vs -0·1, respectively, -1·4 [-5·9 to 3·0]; p=0·522) or in the total patient population (-2·6 vs 0·4, respectively, -2·9 [-6·3 to 0·5]; p=0·092). In most of the cognitive test scores, ADCS-activities of daily living, and Zarit caregiver burden scores, there were no significant differences between the two treatment groups in any of the study populations. The incidence of adverse events and number of discontinuations due to adverse events were similar in the two groups. The most common serious adverse events were stroke (n=3 in memantine group), falls (n=2 in memantine group; n=1 in placebo group), and worsening of dementia (n=2 in memantine group). Interpretation: Memantine seems to improve global clinical status and behavioural symptoms of patients with mild to moderate DLB, and might be an option for treatment of these patients
Paradoxical response of VEGF expression to hypoxia in CSF of patients with ALS
Vascular endothelial growth factor (VEGF) is implicated in motor neurone degeneration. In normal individuals, hypoxia is known to induce an overexpression of VEGF, as measured in CSF. We show that patients with ALS do not manifest this VEGF overexpression in the presence of hypoxia. Although VEGF gene expression is mainly stimulated by hypoxia, we have measured lower VEGF levels in cerebrospinal fluid (CSF) from hypoxaemic patients with amyotrophic lateral sclerosis (ALS) than in CSF from normoxaemic patients with ALS. In contrast, hypoxaemic neurological controls displayed higher levels than normoxaemic neurological controls. There was a negative correlation between VEGF levels and the severity of hypoxaemia in patients with ALS, suggesting deregulation of VEGF in ALS