Biomedical subjects

Kathy Dujardin

Publications and source records attributed to Kathy Dujardin.

7 recordsLinked to original sources

PubMed2006

Utility of the Mattis dementia rating scale to assess the efficacy of rivastigmine in dementia associated with Parkinson's disease.

INTRODUCTION: The severe, cortical, cholinergic depletion accompanying Parkinson's disease (PD) is considered as a highly probable correlate of cognitive and behavioural dysfunction. Recent studies have demonstrated that cholinesterase inhibitors (notably rivastigmine) are beneficial in patients suffering from dementia associated with PD (PDD). However, the primary efficacy variables used in such work came from scales designed for Alzheimer's disease (AD), even though the cognitive symptoms in PD and AD dementia do not overlap completely. The aim of the present study (a double-blind, placebo-controlled clinical trial) was to determine the utility of the Mattis dementia rating scale - the most commonly used scale in PD patients - to assess the efficacy of a 24-week rivastigmine treatment. METHODS: Twenty-eight patients with PD, who constituted a subgroup of patients enrolled to the EXPRESS study (Emre et al, N Engl J Med 2004) participated in this study. They suffered from mild to moderately severe dementia (MMSE scores above 10 and below 24), with an onset of cognitive symptoms occurring at least two years after the diagnosis of PD. Patients were randomly assigned to treatment with rivastigmine (3 to 12 mg per day) or placebo. The Mattis dementia rating scale was administered to patients from six centres in France at the baseline and end-point visits. RESULTS: Compared with placebo, a 24-week rivastigmine treatment led to a significant improvement in the overall score on the Mattis dementia rating scale (p = 0.031), with a trend towards a significant improvement in the "Attention" subscale score (p = 0.061). Correlation analysis showed that in the rivastigmine group, performance on the Mattis "Attention" and "Initiation" subscales appeared to contribute heavily to the improvement in the overall score. Moreover, the latter was also related to an improvement in activities of daily living and a reduction in behavioural disturbances. DISCUSSION: By using the Mattis dementia rating scale (which comprises items that are sensitive to executive dysfunction), the present study confirmed that rivastigmine has a beneficial effect on cognitive function in PDD. Despite our study's small sample size, the Mattis scale was able to detect this improvement and could thus be considered as an interesting outcome measure in further work.

Aged↗

PubMed2005

Role of hypokinesia and bradykinesia in gait disturbances in Huntington's disease: a biomechanical study.

OBJECTIVE: To evaluate specific patterns of locomotion in Huntington's disease (HD) and notably the respective roles of hypokinesia (i. e. a decrease in the amplitude of movement) and bradykinesia (i. e. difficulty in executing a movement, slowness) in gait disturbance. METHODS: Kinematic, spatial (stride length, speed), temporal (cadence, speed, and stride time) and angular gait parameters (joint ankle range) were recorded in 15 early-stage HD patients by means of a video motion analysis system and then compared with 15 controls and 15 Parkinson's disease (PD) patients. Hypokinesia was studied in terms of both spatial (decrease in stride length) and angular gait parameters (decrease in joint ankle range), whereas hyperkinesia was characterized by an increase in joint ankle range. Bradykinesia (defined by a decrease in gait velocity) was also assessed in terms of temporal parameters (cadence, stride time). We studied the influence of clinical symptoms (motor dysfunction, chorea, overall disability and cognitive impairment) and the CAG repeat number on gait abnormalities. RESULTS: we observed a clear decrease in gait speed, a decrease in cadence and an increase in stride time (i. e. bradykinesia) for HD, with significant intra-individual variability. Cadence remained normal in PD. In HD, there was no evidence for a clear decrease in stride length, although the latter is a characteristic feature of hypokinetic gait (such as that observed in PD). Angle analysis revealed the coexistence of hyperkinesia and hypokinesia in HD, which thus participate in gait abnormalities. Gait speed in HD was correlated to the motor part of the UHDRS. CONCLUSION: Gait in HD is mainly characterized by a timing disorder: bradykinesia was present, with severe intra-individual variability in temporal gait parameters.

Adult↗

PubMed2004

Orofacial apraxia in corticobasal degeneration, progressive supranuclear palsy, multiple system atrophy and Parkinson's disease.

OBJECTIVES: To determine whether the assessment of orofacial praxis is useful for the differential diagnosis of parkinsonian syndromes and to understand the neural mechanisms underlying OFA, searching for the respective roles of cortical and subcortical structures. METHODS: Forty-four patients were assessed: 12 with idiopathic Parkinson's disease (IPD), 8 with multiple system atrophy (MSA), 12 with progressive supranuclear palsy (PSP) and 12 with corticobasal degeneration (CBD). An easy bedside scale was used, exploring single gestures, gestures with noise production and multiple sequential gestures. We searched for group and task effects. RESULTS: Patients with CBD were significantly more impaired than those with IPD, MSA or PSP (p<0.001). Our assessment was unable to distinguish between the IPD, MSA and PSP groups. There was a clear task effect in CBD with a major impairment in multiple sequential gestures (p<0.0001). CONCLUSION: Assessment of orofacial praxis helps in the clinical diagnosis of CBD. Patients with IPD, MSA and PSP did not present with OFA. We suggest that the deficit in multiple sequential gestures in CBD is related to simultaneous lesions of the parietal lobule and the supplementary motor area.

Adult↗

PubMed2004

Cognitive and SPECT characteristics predict progression of Parkinson's disease in newly diagnosed patients.

OBJECTIVE: To identify features in cognitive functioning and regional cerebral blood flow (rCBF) in newly diagnosed Parkinson's disease (PD) patients and to determine whether these factors are able to predict the progression of the disease in general and the development of cognitive decline in particular. METHODS: 50 previously treatment-naive PD patients participated in the study. Cognitive assessment and SPECT were performed twice: at the time of diagnosis and then 3 years later. Six patients died or refused to continue. The Mattis dementia rating scale, the WAIS-R digit span test, a word list learning/recall test, a word fluency task and the Stroop word-colour test were used to assess cognitive function. rCBF was measured in 10 pairs of regions of interest. Principal component analysis of the data from the final examination was used to determine which variables allowed the formation of patient subgroups. Thereafter, factorial discriminant analysis (FDA) was performed in order to obtain a predictive model of these final classes. RESULTS: A stepwise procedure enabled the identification of 3 clusters (26, 16 and 2 patients). As the patients in the smallest cluster met the criteria for dementia at the final examination, they were discarded from further analyses. All the cognitive variables contributed to the constitution of the two other clusters. Age, educational level and all the rCBF parameters also contributed but to a lesser extent. Comparison of these groups showed reduced overall cognitive efficiency and an exacerbated subcorticofrontal syndrome in the 16-patient cluster. FDA showed that the best predictive model for the final classes was based on 7 variables: educational level, semantic and alternating word fluency, Stroop interference index and the right medial frontal, left parietal and left lenticular nucleus rCBF findings. CONCLUSION: Even though both cognitive and rCBF parameters help predict the progression of newly diagnosed PD patients and bearing in mind the limitations of the SPECT method used here, it appears that the contribution of cognitive assessment is greater than that of rCBF measurement.

Aged↗

PubMed2004

Deficits in decoding emotional facial expressions in Parkinson's disease.

INTRODUCTION: The basal ganglia have numerous connections not only with the motor cortex but also with the prefrontal and limbic cortical areas. Therefore, basal ganglia lesions can disturb motor function but also cognitive function and emotion processing. The aim of the present study was to assess the consequences of Parkinson's disease (PD) on ability to decode emotional facial expressions (EFEs)-a method commonly used to investigate non-verbal emotion processing. METHODS: Eighteen PD patients participated in the study, together with 18 healthy subjects strictly matched with respect to age, education and sex. The patients were early in the course of the disease and had not yet received any antiparkinsonian treatment. Decoding of EFEs was assessed using a standardized, quantitative task where the expressions were of moderate intensity, i.e. quite similar to those experienced in everyday life. A set of tests also assessed executive function. Visuospatial perception, depression and anxiety were measured. RESULTS: Early in the course of the disease, untreated PD patients were significantly impaired in decoding EFEs, as well as in executive function. The deficits were significantly interrelated, although neither was significantly related to severity of the motor symptoms. Visuospatial perception was not impaired, and the patients' impairment was related neither to their depression nor to their anxiety score. The PD patients' impairment in decoding EFEs was related to a systematic response bias. CONCLUSION: Early in the course of PD, non-verbal emotional information processing is disturbed. This suggests that in PD, nigrostriatal dopaminergic depletion leads not only to motor and cognitive disturbances but also to emotional information processing deficits. The observed correlation pattern does not enable adoption of a clear-cut position in the debate over totally or partially segregated functional organization of the basal ganglia circuits.

Aged↗

PubMed2003

Executive function differences in multiple system atrophy and Parkinson's disease.

The aim of the present study was to assess executive function in patients with multiple system atrophy (MSA) and Parkinson's disease (PD) looking for specific differences and considering motor disability and disease duration. Performance of 11 MSA patients was compared to that of 12 healthy controls and two groups of 12 PD patients, one matched with respect to the severity of motor symptoms and the other with respect to disease duration. Compared to healthy controls, MSA and PD patients both presented executive dysfunction but, in MSA, the impairment was more severe and diffuse. This study suggests that despite the evidence of some differences in executive function in MSA and PD, the contribution of standard neuropsychological examination to the differential diagnosis of both syndromes remains still limited.

Adult↗

PubMed2003

Dysfunction of the human memory systems: role of the dopaminergic transmission.

Human memory is currently considered to consist of different subsystems subserved by different anatomofunctional networks. However, the biochemical basis of memory disturbances remains unclear. The present review focuses on data from studies in Parkinson's disease in order to define the role played by the dopaminergic system in episodic memory and procedural learning. The pattern of episodic memory disturbances in Parkinson's disease is very specific: Parkinson's disease patients display a preserved ability to encode, store and consolidate new information but have difficulties in retrieving it. This deficit is particularly observed when patients have to self-initiate remembering strategies, as they are unimpaired when retrieval cues are explicitly presented. This probably reflects executive dysfunction, and is related to the disruption of the associative striato-prefrontal circuit. It is observed with verbal as well as visuospatial material. On procedural learning tasks, Parkinson's disease patients display a lower progressive performance enhancement over trials than healthy controls. However, this impairment mainly concerns the initial learning phase and appears to be highly dependent on the motor demands of the task. The role played by dopamine depletion in these deficits remains a subject of debate as some studies suggest the involvement of the dopaminergic system in cognitive function, although other results do not support it. Other neurotransmission systems are probably involved in the pathophysiology of cognitive dysfunction in Parkinson's disease, and currently it is the cholinergic hypothesis that is the most considered.

Brain Chemistry↗