Search PubMed⌕ Search

Biomedical subjects

L Defebvre

Publications and source records attributed to L Defebvre.

At least 37 records · Page 2Linked to original sources
PubMed2006

Clinical and economic results of bilateral subthalamic nucleus stimulation in Parkinson's disease.

BACKGROUND: High frequency stimulation of the subthalamic nucleus (STN) is an alternative but expensive neurosurgical treatment for parkinsonian patients with levodopa induced motor complications. OBJECTIVE: To assess the safety, clinical effects, quality of life, and economic cost of STN stimulation. METHODS: We conducted a prospective multicentre study in 95 consecutive Parkinson's disease (PD) patients receiving bilateral STN stimulation and assessed its effects over 12 months. A double blind randomised motor evaluation was carried out at 3 month follow up, and quality of life, self care ability, and predictive factors of outcome following surgery were assessed. The cost of PD was estimated over 6 months before and after surgery. RESULTS: The Unified Parkinson's Disease Rating Scale (UPDRS) motor score improved by 57% (p<0.0001) and activities of daily living improved by 48% (p<0.0001) at 12 month follow up. Double blind motor scoring improved by 51% at 3 month follow up (p<0.0001). The total PD Quality of Life Questionnaire (PDQL-37) score improved by 28% (p<0.001). The better the preoperative motor score after a levodopa challenge, the better the outcome after STN stimulation. Five patients developed an intracerebral haematoma during electrode implantation with permanent after effects in two. The 6 month costs of PD decreased from 10,087 euros before surgery to 1673 euros after surgery (p<0.0001) mainly because of the decrease in medication. These savings allowed a return on the procedure investment, estimated at 36,904 euros over 2.2 years. CONCLUSIONS: STN stimulation has good outcomes with relatively low risk and little cost burden in PD patients with levodopa induced motor complications.

Activities of Daily Living↗
PubMed2006

Functional data analysis for gait curves study in Parkinson's disease.

In Parkinson's disease, precise analysis of gait disorders remains essential for the diagnostic or the evaluation of treatments. During a gait analysis session, a series of successive dynamic gait trials are recorded and data involves a set of continuous curves for each patient. An important aspect of such data is the infinite dimension of the space data belong. Therefore, classical multivariate statistical analysis are inadequate. Recent methods known as functional data analysis allow to deal with this kind of data. In this paper, we present a functional data analysis approach for solving two problems encountered in clinical practice: (1) for a given patient, assessing the reliability of the gait curves corresponding to the different trials (2) performing intra individual curves comparisons for assessing the effect of a therapy. In a first step, each discretized curve was interpolated using cubic B-splines bases in order to ensure the continuous character of data. A cluster analysis was performed on the smoothed curves to assess the reliability and to identify a subset of representative curves for a given patient. Intra individual curves comparisons were carried out in the following way: (1) functional principal component analysis was performed to describe the temporal structure of data and to derive a finite number of reliable principal components. (2) These principal components were used in a linear discriminant analysis to point out the differences between the curves. This procedure was applied to compare the gait curves of 12 parkinsonian patients under 4 therapeutic conditions. This study allowed us to develop objective criteria for measuring the improvements in a subject's gait and comparing the effect of different treatments. The methods presented in this paper could be used in other medical domains when data consist in continuous curves.

France↗
PubMed2005

Elevated IL-6 and TNF-alpha levels in patients with ALS: inflammation or hypoxia?

Abnormal levels of interleukin (IL)-6 were described in patients with ALS, related to an inflammatory process. The authors compared IL-6 and tumor necrosis factor alpha (TNF-alpha) levels in CSF and sera from 10 hypoxemics and 10 normoxemics patients with ALS to those of 10 hypoxemics and 10 normoxemics neurologic controls. The same pattern exists in patients with ALS and controls: the highest levels are found in hypoxic conditions and undetectable levels are found in normoxemic conditions. Elevated IL-6 levels in ALS could correspond to a normal response to hypoxemia.

Aged↗
PubMed2005

ERG and anatomical abnormalities suggesting retinopathy in dementia with Lewy bodies.

The authors used flash electroretinography to demonstrate dysfunction of the photopic and scotopic retina in patients with dementia with Lewy bodies and visual hallucinations (VHs) compared with patients with Parkinson disease, patients without VHs, and controls. The retinal dysfunction may be related to slight alteration of the photoreceptors and numerous pale inclusions in the outer plexiform layer found at the post mortem examination, suggesting a specific retinopathy.

Aged↗
PubMed2005

The place of perceptual analysis of dysarthria in the differential diagnosis of corticobasal degeneration and Parkinson's disease.

OBJECTIVE: To characterize the dysarthria in patients with corticobasal degeneration (CBD) and determine if analysis of speech in isolation helps to distinguish CBD patients from patients with Parkinson's disease (PD). METHODS: 60 subjects were assessed by means of perceptual analysis of speech: 15 patients with CBD, 15 patients with PD and 30 control subjects. A detailed profile was furnished with the help of 33 perceptual items. A global perceptual approach was used to classify patients by judges blind to the medical diagnosis. Rating scales were adapted to quantify the degree of spasticity and hypokinesia in the speech of each patient. RESULTS: Dysarthria was frequent in CBD even though it remained mild for a long period of time. Group analysis revealed the importance of temporal errors of speech control in CBD patients while voice disturbances were most frequent in PD patients. However, attempts to classify patients according to global perceptual analysis remained below a reasonable level of clinical acceptability. Finally, even though the widespread neuropathological changes suggest that deviant speech dimensions of several types of dysarthria might be found in CBD, evidence for a mixed dysarthria with presence of spastic elements could not be established. CONCLUSION: The findings support the view that even though perceptual analysis is mandatory in the management of dysarthric patients, it does not help in the clinical differential diagnosis of CBD.

Aged↗
PubMed2005

Progressive MRI abnormalities in late recurrence of Sydenham's chorea.

We report four cases of adult recurrence of Sydenham's chorea (SC). The first episodes all followed childhood tonsillopharyngitis. Many years later, subsequent episodes appeared after the triggering circumstances: throat or cutaneous infection, pregnancy, childbirth, contraceptive treatment or stress. Other inflammatory diseases were ruled out and streptococcal serology was weakly positive. Magnetic Resonance Imaging (MRI) revealed focal areas of T2 hypersignal in the caudate nucleus, the pallidum, the putamen and the white matter. One year later, repeat MRI variously gave evidence of the persistence, disappearance or even new appearance of abnormalities. Specific features of SC recurrence in the adult may include: a personal history of chorea after a throat infection during childhood; a second episode of isolated chorea with or without slight neuropsychological disorders; streptococcal serology weakly positive; focal hypersignals involving the basal ganglia; the triggering circumstances. Since SC is considered to be an autoimmune disease, the progressive MRI abnormalities suggest that certain circumstances may trigger the reactivation of persistent immune disorders.

Adult↗
PubMed2005

[Parkinson's disease, progressive lumbar kyphosis and focal paraspinal myositis].

INTRODUCTION: The camptocormia (bent spine) is characterized by a severe forward flexion of the thoracolumbar spine which disappears in the supine position. Clinical case. We describe a typical case observed in a parkinsonian patient. The MRI, electromyogram and biopsy of the paraspinal muscles revealed a typical myositis pattern. DISCUSSION: This case, the sixth published to our knowledge, confirms that focal myositis is associated with the camptocormia in Parkinson's disease. Typically it is observed in male subjects, appearing 4 to 6 years after the onset of Parkinson's disease, in fluctuating patients treated by an association of L-Dopa and agonist. It appears quickly and becomes the most important symptom. Antiparkinsonian drugs are useless. CONCLUSION: This exceptional picture raises original pathophysiological and therapeutic questions. Systematic studies should be performed in order to detail the pathophysiological link between these 3 entities: Parkinson's disease, focal myositis and camptocormia.

Disease Progression↗
PubMed2005

[Can meningoencephalitis be caused by Chlamydiae pneumoniae?].

INTRODUCTION: Meningoencephalitis attributed to Chlamydiae pneumoniae has rarely been reported in the literature. OBSERVATION: We describe the case of a 21-year-old-man admitted for a meningeal syndrome and fever associated with respiratory symptoms and a temporal syndrome. Even though the clinical presentation and certain serological results suggested Chlamydiae infection, some of the biological data raised the possibility of Epstein Barr Virus infection. Intravenous fluoroquinolone therapy led to a successful outcome. CONCLUSION: Meningoencephalitis associated with non neurological symptoms, especially respiratory symptoms, is suggestive of Chlamydia pneumoniae infection. A broad spectrum antibiotic should be prescribed.

Adult↗
PubMed2005

[Pathophysiological mechanisms implicated by high-frequency stimulation in Parkinson's disease: the restoration of high and low frequency oscillatory systems].

INTRODUCTION: Increased neuronal activity in the internal pallidum (GPi) and the subthalamic nucleus (STN) has been clearly demonstrated in Parkinsonian models, and the two structures have thus been selected as therapeutic targets for functional neurosurgery. High-frequency electrical stimulation of the GPi or the STN improves the parkinsonian symptoms but also dyskinesias directly by GPi stimulation or indirectly by reduction of L-Dopa associated with STN stimulation. According to Alexander's model of the organisation of the basal ganglia, electrical stimulation of GPi or STN should have led to uncontrolled hyperkinesia. This apparent paradox could be explained on one hand by the involvement of different anatomo-functional areas within these structures and on the other by spatial and temporal changes in neuronal discharge patterns in the basal ganglia which in turn produce variations in synchronisation. RESULTS: Event-related (de)synchronisation (ERD) has enabled us to study variations in subcortico-cortical oscillatory activity: it has been shown that high-frequency electrical stimulation of the GPi/STN increases desynchronisation of low frequency rhythms (mu and beta,<30 Hz) during movement preparation and execution and augments post-movement synchronisation. Stimulation also decreases the abnormal frontocentral spreading of desynchronisation during movement preparation. CONCLUSIONS: In accordance with previous coherence analyses, electrical stimulation of STN is likely to restore the activity of high-frequency and low-frequency systems, as evidenced by a decrease in the hypersynchronisation of low-frequency rhythms at rest and restoral of a high-frequency rhythm during movement. Stimulation may improve spatial selectivity by activating the selected programs in conjunction with the primary sensorimotor cortex, whilst inhibiting competitive programs represented by abnormal spreading outside the primary sensorimotor cortex.

Basal Ganglia↗
PubMed2005

Brain MRI in late-onset multiple sclerosis.

Multiple sclerosis (MS) with clinical onset after 50 years of age is unusual (between 1 and 6%) and is frequently misdiagnosed. Furthermore, brain magnetic resonance imaging (MRI) abnormalities are frequently observed in subjects over 50 years of age. The aim of this study was to describe brain MRI in late-onset MS to evaluate the sensitivity and specificity of radiological MS criteria in patients aged over 50 years. We evaluated the brain MRI of 20 patients with onset of MS after 50 years of age. We compared these MRI with 26 controls matched for age, sex and vascular risk factors. MRI were blindly analysed by two neuroradiologists according to Paty et al.'s [Neurology38 (1988) 180] criteria, Fazekas et al.'s [Neurology38 (1988) 1822] criteria and Barkhof et al.'s [Brain120 (1997) 2059] criteria. The mean age at MRI scanning was 58 years. Sensitivity was 90% for Paty et al.'s criteria, 80% for Fazekas et al.'s criteria and 85% for Barkhof et al.'s criteria. Specificity was 54% for Paty et al.'s criteria, 69% for Fazekas et al.'s criteria and 65% for Barkhof et al.'s criteria. Barkhof et al.'s criteria are less specific in older patients than in young patients. We suggest that spinal cord MRI and cerebrospinal fluid analysis should be systematically performed in suspected late-onset MS in order to increase the specificity of the diagnosis.

Aged↗
PubMed2005

Disturbance of sensory filtering in dementia with Lewy bodies: comparison with Parkinson's disease dementia and Alzheimer's disease.

INTRODUCTION: Prepulse inhibition (PPI) is considered to mirror an organism's ability to filter out irrelevant sensory or cognitive information. The disruption of PPI has never been studied in individuals suffering from dementia with Lewy bodies (DLB). As attention deficits largely contribute to cognitive impairment in DLB, an investigation with a PPI paradigm is useful for differential diagnosis of DLB versus Alzheimer's disease (AD) and Parkinson's disease dementia (PDD). OBJECTIVE AND METHODS: PPI of the N1/P2 component of auditory evoked potentials was used to investigate the early stages of attention selectivity in 10 DLB, 10 AD, and 10 PDD patients, as well as in 10 healthy controls. The PPI paradigm consisted of the presentation of sound pulses (40 ms, 115 dB) preceded by a prepulse (40 ms, 80 dB). Sound stimuli were presented in a total of 80 trials in a pseudo-random order. RESULTS: Non-parametric analyses of variance revealed a significant group effect on the 120 ms lead interval. Retrospective analyses revealed that PPI was significantly reduced in DLB compared to healthy controls and AD. In the PDD group, the disturbance was of intermediate intensity. CONCLUSION: The present study revealed a severe disturbance of PPI in DLB patients. The DLB patients displayed a specific disruption profile in terms of magnitude as well as time course.

Acoustic Stimulation↗
PubMed2004

Statistical tools for clinical gait analysis.

Gait analysis studies involve continuous curves of data measured over a gait cycle. Curve analysis and interpretation require adequate statistical methods. Three principal problems may be encountered in clinical practice: (i) the reliability of gait curves for a given patient, (ii) classifying a new subject as belonging to a given population or not and (iii) comparison of two populations (independent or paired). This paper presents three statistical tools for solving these problems: (i) intra-class correlation coefficients, (ii) confidence bands for a population (iii) a combination of analysis of variance and confidence bands for the difference between the means and shows how they can be used in clinical practice.

Adult↗
PubMed2004

Influence of aging on cortical activity associated with a visuo-motor task.

The aim of this study was to determine how cerebral aging influences the pattern of cortical oscillatory activity when a targeting movement with visual control is planned. Changes in cortical oscillatory activity were assessed by recording the event-related (de)synchronization (ERD/S) of micro and beta rhythms. Young and elderly subjects performed a distal movement, a proximal movement and a visuo-guided targeting movement. Our results demonstrated an increase in micro ERD over ipsilateral regions and showed the spatial extent of micro ERD over parietocentral and parietal regions during motor planning in elderly subjects compared to young ones. After the movement, the beta ERS was significantly modified (a decrease in slope and amplitude) in elderly subjects. The most pronounced age-related changes in ERD/S pattern were observed for the targeting movement. Our results suggest that motor planning is less efficient in elderly subjects. This deficit might result from impaired parietal integrative function and/or changes in inputs from subcortical structures. Subsequently, the changes observed in the post-movement phase might reflect a decrease in (reafferent) sensory inputs and hence impaired their input processing.

Adult↗
PubMed2004

[Neuromeningeal tuberculosis: the contribution of genetic amplification to diagnosis].

Neurological manifestations of tuberculosis are rare, especially in immunocompetent subjects. The heterogeneity of clinical and radiological features induces frequently a delay for diagnosis. The aim of the study was to describe clinical and radiological presentation of 11 cases of neuro-tuberculosis and to evaluate clinical outcome. We performed clinical, CSF, MRI and outcome evaluation in all patients. We also performed a mycobacterium analysis by polymerase chain reaction (PCR). Patients were 6 men and 5 women with a mean age of 45.4 years. Clinical presentations were meningeal symptoms in 9 cases and focal manifestations in 4 cases. CSF was abnormal in 82 p.cent of cases (protein increase in 73 p.cent, pleiocytosis in 73 p.cent, hypoglycorrhachia in 45 p.cent and hypochlorrhachia in 36 p.cent). The best diagnostic test was PCR (positive in 45 p.cent of cases). CSF cultures were positive in only 2 cases (18 p.cent). Only 2 patients had chest involvement. MRI was abnormal in 64 p.cent of cases showing pseudo-tumor, arachnoiditis, vascular lesions or medullar involvement. Outcome was good in all cases but two (one patient died and one patient had paraplegia possibly related to late diagnosis). Neurological manifestations of tuberculosis are extremely various in terms of clinical and radiological presentation. The best diagnostic test seems to be tuberculosis PCR. Outcome is frequently favorable if late diagnosis is avoided.

Adult↗
PubMed2004

[Usefulness and limitations of polymygraphic recordings in dystonia].

INTRODUCTION: Diagnosis of dystonia is based on well-known clinical findings, but electrophysiological explorations can help to establish the diagnosis. METHODS: We report 179 patients presenting primary or secondary dystonia. Polymyographic recordings were available for all. We studied activation patterns of agonist and antagonists muscles (prolonged bursts, co-contraction), presence of antagonistic gestures and other associated movement disorders such as tremor or myoclonus. RESULTS: 83.9 percent of patients presented abnormalities which evoked dystonia (prolonged bursts: 75.3 percent, co-contraction: 48.7 percent, successful antagonistic gesture successful with reduction or suppression of EMG activity, 8.7 percent). For the patients who presented no EMG abnormality, diagnosis was maintained in 22 cases because of the limitations of the exploration: intermittent symptoms, dystonia involving deep muscles which were not recorded by the surface electromyogram, or difficulties to reproduce the conditions of apparition of the dystonic symptoms during examination or to recognize a pathologic EMG pattern in hand cramps for instance. Another diagnosis was retained because of the polymyographic findings in 16.2 p.cent of these patients, particularly those who had tremor associated with dystonia (essentially diagnosis of primary writing tremor). CONCLUSION: Polymyography is an effective tool for confirming clinical findings.

Adult↗
PubMed2004

[The presentation of small-cell lung cancer with metastatic carcinomatous encephalitis in a non-Hodgkin's lymphoma patient].

BACKGROUND: Carcinomatous encephalitis or milary cerebral metastases characterized by signs of diffuse encephalopathy is a rare form of brain metastases. Tiny tumor nodules are seen throughout the cortical and subcortical gray matter. OBSERVATION: We report the case of a patient with a history of non-Hodgkin lymphoma who developed carcinomatous encephalitis probably secondary to small-cell lung cancer. This case is discussed in light of findings of 16 cases of carcinomatous encephalitis reported in the literature. We discuss clinical, radiological, histological, pathophysiological characteristics and the survival of this form. CONCLUSION: The frequency of carcinomatous encephalitis is underestimated because clinical expression is non specific. Brain magnetic resonance imaging must be performed in all patients presenting encephalopathy without an obvious cause.

Aged↗