Biomedical subjects

Bernard Pillon

Publications and source records attributed to Bernard Pillon.

9 recordsLinked to original sources

PubMed2005

Bilateral deep-brain stimulation of the globus pallidus in primary generalized dystonia.

BACKGROUND: Severe forms of dystonia respond poorly to medical treatment. Deep-brain stimulation is a reversible neurosurgical procedure that has been used for the treatment of dystonia, but assessment of its efficacy has been limited to open studies. METHODS: We performed a prospective, controlled, multicenter study assessing the efficacy and safety of bilateral pallidal stimulation in 22 patients with primary generalized dystonia. The severity of dystonia was evaluated before surgery and 3, 6, and 12 months postoperatively during neurostimulation, with the use of the movement and disability subscores of the Burke-Fahn-Marsden Dystonia Scale (range, 0 to 120 and 0 to 30, respectively, with higher scores indicating greater impairment). Movement scores were assessed by a review of videotaped sessions performed by an observer who was unaware of treatment status. At three months, patients underwent a double-blind evaluation in the presence and absence of neurostimulation. We also assessed the patients' quality of life, cognition, and mood at baseline and 12 months. RESULTS: The dystonia movement score improved from a mean (+/-SD) of 46.3+/-21.3 before surgery to 21.0+/-14.1 at 12 months (P<0.001). The disability score improved from 11.6+/-5.5 before surgery to 6.5+/-4.9 at 12 months (P<0.001). General health and physical functioning were significantly improved at month 12; there were no significant changes in measures of mood and cognition. At the three-month evaluation, dystonia movement scores were significantly better with neurostimulation than without neurostimulation (24.6+/-17.7 vs. 34.6+/-12.3, P<0.001). There were five adverse events (in three patients); all resolved without permanent sequelae. CONCLUSIONS: These findings support the efficacy and safety of the use of bilateral stimulation of the internal globus pallidus in selected patients with primary generalized dystonia.

Adolescent↗

PubMed2005

Effects of internal clock and memory disorders on duration reproductions and duration productions in patients with Parkinson's disease.

Patients with Parkinson's disease (PD) exhibit deficits in perceptual and motor timing as well as impairments in memory and attentional processes that are related to dysfunction of dopaminergic systems in the basal ganglia. The aim of the present study was to assess the relationships existing between impaired duration judgments and defective memory and attention in PD patients. We compared time performance of medicated PD patients and control subjects on a duration reproduction task that is highly memory-dependent, and on a duration production task that could reveal effects of changes in the speed of internal time-keeping mechanisms. Each task was performed in a control counting condition and in a condition requiring divided attention between the temporal task and a concurrent reading task. Moreover, PD patients and control subjects were assessed on memory and attention using a battery of neuropsychological tests. The results revealed that in the concurrent reading condition of the reproduction task, duration judgments tended to be more variable in PD patients than in control subjects. Moreover, variability of duration reproductions was correlated with both measures of memory and of disease severity. In the concurrent reading condition of the production task, duration judgments were significantly shorter in PD patients than in control subjects, and accuracy of duration productions was correlated with scores on sub-tests of short-term memory. The findings suggest that the administration of dopamine did not entirely remove the memory deficits in PD patients. Moreover, DA treatment would have abnormally accelerated the rate of the internal clock leading to shorter duration productions in PD patients. The whole results indicate that dopamine administration in patients might have overshadowed the slowing rate of the internal clock usually reported in non medicated PD patients, without entirely restoring all of the memory functions.

Aged↗

PubMed2004

Executive dysfunctions as potential markers of familial vulnerability to bipolar disorder and schizophrenia.

Attentional and executive impairments have been found both in patients with schizophrenia and in their unaffected first-degree relatives, suggesting that they might be considered as familial vulnerability markers. Several studies have shown that the performance of bipolar patients does not significantly differ from that of schizophrenic patients, so that executive and attentional deficits might not be specific to schizophrenia. In the present study, we aimed to identify executive dysfunctions in schizophrenia and bipolar disorder that might be vulnerability trait markers specific to one or common to both of these diseases. We assessed cognitive performance of euthymic bipolar and schizophrenic patients, their unaffected first-degree relatives and a healthy control group, using neuropsychological tasks to test different components of executive function: the Verbal Fluency Test, the Stroop Word Colour Test, the Wisconsin Card Sorting Test and the Trail Making Test. The two groups of patients and their unaffected relatives demonstrated disproportionately increased slowness on the Stroop test in comparison to the normal healthy group. Patients with schizophrenia performed poorly on all the tests in comparison to the normal healthy subjects, while no other impairment was observed in the bipolar patients and in the relatives of schizophrenic and bipolar patients. Enhanced susceptibility to interference and reduced inhibition could be transnosographical markers for a shared familial vulnerability common to schizophrenia and bipolar disorders.

Adult↗

PubMed2004

Frontal assessment battery and differential diagnosis of frontotemporal dementia and Alzheimer disease.

BACKGROUND: The different distribution of pathologic features in frontotemporal dementia (FTD) and Alzheimer disease (AD) predicts a predominant dysexecutive syndrome in FTD. The Frontal Assessment Battery (FAB) has previously been validated in diseases associated with a frontal lobe dysfunction. OBJECTIVE: To evaluate the sensitivity of the FAB to differentiate FTD and AD. DESIGN: Comparison study. SETTING: Memory Clinic of the Salpêtrière Hospital, Paris, France. PATIENTS: Twenty-six patients with FTD and 64 patients with AD. MAIN OUTCOME MEASURES: Comparison of FAB and Mini-Mental State Examination (MMSE) scores between patients with FTD and those with AD. RESULTS: The mean +/- SD FAB scores significantly differed between patients with FTD (7.6 +/- 4.2) and those with AD (12.6 +/- 3.7) (P<.001), but not MMSE scores. The FAB correctly identified 78.9% of the patients. These results were maintained in a subgroup of mildly demented patients (MMSE score, > or =24). In these patients, a cutoff score of 12 on the FAB was optimal to differentiate both disorders (sensitivity, 77%; specificity, 87%). CONCLUSIONS: The FAB takes less than 10 minutes to administer and provides an objective measure to distinguish FTD from AD in mildly demented patients.

Adult↗

PubMed2003

Metabolic correlates of behavioral and affective disturbances in frontal lobe pathologies.

OBJECTIVE: Although previous studies have shown that the human frontal cortex is involved in the experience of emotions as well as in social behavior, data regarding the exact anatomical substrates of behavioral and affective deficits in frontal lobe pathologies are still scarce. The aim of this study was to investigate the metabolic correlates of these deficits in a group of non-selected consecutive patients with frontal lobe lesions. PATIENTS AND METHODS: Clinicometabolic correlations between several emotional and social parameters and metabolic patterns in the frontal cortex and amygdala were investigated in 32 patients with frontal lobe pathologies. The behavioral disturbances were evaluated using the Lhermitte's informant questionnaire. Regional cerebral glucose metabolism was measured with [(18)F] fluorodeoxyglucose and high-resolution positron emission tomography. Statistical analysis was performed using both single variable correlation and multiple regression analyses. RESULTS: Both single variable and multivariate analyses demonstrate that decreased regional glucose metabolism in the right medial area 10 was associated with apathy. There were also significant negative relationships between metabolism in the right orbitofrontal cortex and stereotypy and indifference to rules. Impulsiveness, personality disturbances and loss of emotional control were associated with decreased metabolism in the left amygdala. CONCLUSIONS: In terms of clinicometabolic correlations, the present data support the implication of different functional anatomic systems in frontal lobe-related behavioral and affective disturbances. In particular, they imply that the classically described symptoms of impaired behavioral control may be related to right orbitofrontal cortex hypometabolism whereas impaired regulation of emotions may result from a functional damage of the left amygdala.

Adult↗

PubMed2003

Dopamine and cognitive function.

PURPOSE OF REVIEW: Although the cognitive deficits of idiopathic Parkinson's disease are now relatively well known, their neuropsychological and neurobiological basis are still discussed. RECENT FINDINGS: As well as recent findings on cognitive changes and their underlying mechanisms, we will review new approaches concerning the effects of levo-dihydroxyphenylalanine, those of deep-brain stimulation and recent developments on personality disorders. SUMMARY: Future research directions concern the relative influence of the striatofrontal loops in cognition and personality, and the respective contribution of subcortical and cortical lesions or dysfunctions, both in dementia and in specific cognitive and personality changes.

Brain Chemistry↗

PubMed2002

Compulsions, Parkinson's disease, and stimulation.

Pathophysiological models suggest that obsessive compulsive disorder (OCD) might be associated with dysfunctions in cortico-striato-pallido-thalamo-cortical neuronal circuits. We implanted subthalamic electrodes to alleviate parkinsonian symptoms in two patients who had Parkinson's disease and a history of severe OCD. Parkinsonian disability improved postoperatively in both patients, and 2 weeks after the procedure, their compulsions had disappeared and obsessive symptoms improved (58% improvement for patient 1 on the Yale-Brown obsessive compulsive scale, 64% for patient 2). The improvements in these two patients suggest that high-frequency stimulation could improve function in the subcortical-limbic circuitry in patients with severe OCD.

Electric Stimulation Therapy↗

PubMed2002

Procedural learning and striatofrontal dysfunction in Parkinson's disease.

The neural basis of procedural learning remains controversial. We further analyzed procedural learning in nondemented patients with Parkinson's disease (PD) according to the specific demands of the tasks and the severity of striatal and frontal lobe dysfunction. In the first experiment, the performance of 20 nondemented PD patients and matched normal control subjects was studied in two procedural learning tasks, rotor pursuit and mirror reading, that differ in terms of motor and cognitive involvement. A second experiment further assessed the relationship between learning in mirror reading and executive functions in a new group of 15 nondemented PD patients. In rotor pursuit, PD patients significantly progressed across the first sessions, although their asymptotic performance was inferior to that of controls. In mirror reading, both experiments showed substantial learning in PD patients considered as a group. However, subsequent analyses allowed us to distinguish PD patients without executive dysfunction, whose learning was normal, from PD patients with executive dysfunction, whose learning was severely impaired. These results confirm the involvement of striatofrontal circuits in procedural learning and indicate that the intervention of the frontal network may depend on the characteristics of the task.

Aged↗

PubMed2002

Neuropsychological assessment for management of patients with deep brain stimulation.

The inclusion of cognitive and behavioural criteria has been recommended for the management of patients with deep brain stimulation. A neuropsychological assessment may contribute to different issues: (1) selection of the best candidates for surgery, (2) evaluation of the consequences of surgery, (3) research of the best electrode implantation. Recent neuropsychological studies indicate that (1) with appropriate inclusion criteria, the effects of surgery on cognitive functions are limited; (2) an aggravation of behavioural disorders might be related to subthalamic nucleus (STN) stimulation and depend on electrode location; (3) subthalamic nucleus stimulation, but not the internal globus pallidus stimulation, improves psychomotor efficiency and working memory. These results would suggest that the implanted electrodes are not solely targeting the motor circuit and that the cognitive and motor circuits are not completely segregated.

Basal Ganglia↗