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O Godefroy

Publications and source records attributed to O Godefroy.

At least 37 records · Page 2Linked to original sources
PubMed1998

Unusual MRI findings in grey matter heterotopia.

We report unusual MRI patterns in patients with grey matter heterotopia. Standard T1- and T2-weighted spin-echo and inversion-recovery sequences were used in 22 patients presenting with seizures or developmental delay. The images were reviewed for signal change surrounding white matter and for atypical size, morphology or topography. We found 10 cases of subependymal heterotopias 11 of focal subcortical heterotopia and of diffuse subcortical heterotopia. On clinical or MRI grounds, 8 cases were considered unusual: 2 of the subependymal type, 2 of focal subcortical heterotopia with white matter abnormalities, 2 of focal subcortical heterotopia with no clinicoradiological correlation 1 of extensive hemispheric subcortical heterotopia and 1 of diffuse subcortical heterotopia confined to the frontal lobe. The classical classification of heterotopia enables easy radiological diagnosis even in cases with unusual patterns. In some cases, heterogeneity and high signal in surrounding white matter can be found. Cortical dysplasia is the most frequent associated malformation.

Adolescent↗
PubMed1998

PET study and neuropsychological assessment of a long-lasting post-encephalitic parkinsonism.

A 76-year old woman was affected by lethargic encephalitis in 1918, at the age of 3 months. Long-term clinical follow-up with late neuropsychological evaluation revealed post-encephalitic parkinsonism, which worsened very slowly and was improved by levodopa. Obsessive and compulsive disorders (OCD) were associated to nosophobia. Neuropsychological evaluation showed mild visuocontructional memory deficit, which was isolated. 18 Fluoro-Dopa PET demonstrated a severe bilateral and symmetrical reduction in fluoro-dopa uptake, which was more marked in the putamen than in the caudate. Thus, the pattern of dopaminergic denervation was similar to the one observed in idiopathic Parkinson's disease.

Aged↗
PubMed1998

Electrodermal level asymmetry in a unilateral brain-damaged patient.

The purpose of this article is to report on a patient with right frontal damage who exhibited a strong left > right asymmetry of skin conductance levels (SCLs). Comparison with a control group indicates that this asymmetry resulted only from a higher SCL on the left hand. Such a result suggests that the frontal lesion has induced a contralateral disinhibition and is consistent with the idea of a contralateral inhibitory control of tonic electrodermal activity in the case of a healthy hemisphere. Peripheral factors, such as sweating or temperature seem unrelated to the SCL asymmetry and a possible influence of motor weakness is also rejected following comparison with a second patient who presented the same motor disorder without atypical SCL asymmetry. In contrast to SCLs, no asymmetry in skin conductance response amplitudes was observed in the former patient. This discrepancy is in line with previous observations showing that tonic and phasic EDA could depend on different neurophysiological controls.

Brain Damage, Chronic↗
PubMed1998

[Brain stem metastasis revealing bronchopulmonary cancer: 2 cases].

INTRODUCTION: Brainstem metastasis is a very rare revealing feature of lung carcinoma. EXEGESIS: We report two cases of brainstem metastasis revealing lung carcinoma. In the first case, diagnosis was made on stereotaxic biopsy. In the second, the biopsy was not necessary as lung lesion was observed on thoracic CT-scan. Diagnosis of metastasis is difficult when a brainstem tumor occurs. CONCLUSION: Stereotaxic biopsy is an interesting tool to distinguish between primary lesion and metastasis, but only when diagnosis work-up of primary cancer is negative.

Adenocarcinoma↗
PubMed1998

Brain-behaviour relationships. Some models and related statistical procedures for the study of brain-damaged patients.

The study of brain-damaged patients provides the opportunity to examine the anatomy of brain functions, and has been renewed by the development of structural neuroimaging. Despite the development of neuroimaging and neuropsychological assessment, major uncertainties persist on the exact delimitation of the brain areas involved in specific processes, and these contribute to the enduring controversies over the effective lesions associated with neuropsychological disorders. These uncertainties are mainly due to the methods used in the study of brain-behaviour relationships, which frequently rely on a group comparison design. The aim of this study was to provide models for the study of brain-behaviour relationships and to assess the reliability of related statistical procedures. In the present work, four theoretical modes of brain-behaviour relationship consistent with neuropsychological data are put forward: unicity, equivalence, association and summation. The first experimental study was based on a simulated population of patients. Lesions associated with the occurrence of a deficit were predetermined according to modes of brain-behaviour relationship and were compared with lesions selected by statistical analysis. The study showed that (i) the group comparison design did not allow determination of the effective lesion, (ii) stepwise regression analysis was sensitive to the relative frequency of lesions, especially when the occurrence of a deficit depended on two lesions, but did not allow determination of the mode of brain-behaviour relationship, and (iii) the classification tree test described the data very satisfactorily and permitted the determination of the mode of brain-behaviour relationships. In order to assess the validity of statistical analyses, a second study was performed in which lesion locations associated with motor weakness in stroke patients were examined. Selected lesions were compared with the anatomy of the human motor system. The study mainly showed that (i) the stepwise regression analysis of selected lesions was not related to the presence of a motor deficit, and (ii) the classification tree test provided perfect agreement with motor weakness predicted by lesion locations and suggested an equivalence mode of brain-behaviour relationship consistent with current neurological knowledge. These studies provide models of brain-behaviour relationships and related statistical procedures that may allow more precise documentation of the anatomy of brain functions and its pathology, and further investigation of the modalities of brain-behaviour relationships.

Behavior↗
PubMed1998

Helical CT for the follow-up of cervical internal carotid artery dissections.

PURPOSE: The aim of this study was to assess the changes over time of internal carotid artery (ICA) dissections by using helical CT. METHODS: Twenty-seven patients with 30 angiographically proved ICA dissections were followed up with helical CT at 7 to 62 months (median, 24 months) after conventional angiography. CT scans, analyzed independently by two radiologists in a blinded fashion, were evaluated for the presence of mural thickening, aneurysmal formation, and arterial occlusion. In cases without persisting occlusion or aneurysm, we measured the external diameter of the ICA at its upper segment. RESULTS: The interobserver agreement was good. Mild mural thickening was observed in four cases of 30 previously dissected ICAs. All stenotic and nearly occlusive dissections without an aneurysm (n = 12) reverted to a normal or nearly normal diameter. Half the aneurysms resolved spontaneously (four of eight). Of the 10 occluded ICAs, nine were recanalized, but their external diameter was significantly smaller than that of normal carotid arteries, and a hypoplastic appearance was seen throughout the cervical segment of the ICA in three cases. CONCLUSION: Most arterial lesions tend to improve or disappear spontaneously, but persisting ICA narrowing may be observed in the late course of occlusive-type dissections.

Adult↗
PubMed1998

Contrast-enhanced three-dimensional fast imaging with steady-state precession (FISP) MR angiography of supraaortic vessels: preliminary results.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the effectiveness of contrast-enhanced fast three-dimensional (3D) MR angiography in depicting both the carotid and vertebral arteries in their cervical portions and to compare MR angiography with conventional angiography for the evaluation of arteriosclerotic disease. METHODS: Twenty-seven patients with ischemic cerebral events in the anterior (n = 18) and posterior (n = 9) circulation underwent contrast-enhanced 3D MR angiography in the coronal plane. MR angiograms were examined in a blinded fashion by two observers independently. Stenosis was classified according to the appearance of the residual lumen (no stenosis, mild stenosis, moderate stenosis, severe stenosis, occlusion). Conventional angiography was used as the standard of reference. RESULTS: Proximal great vessels and carotid siphons were not assessable on MR angiograms in 35% of cases owing to limited coverage. All cervical and petrous segments of the internal carotid arteries (ICAs) and 93% of the extracranial vertebral arteries were assessable. Flow-related artifacts were observed in seven cases of severe stenosis, including three with signal void at the site of narrowing and four with signal loss in the distal ICA. Interobserver agreement was good and significant. Overall agreement between 3D MR angiography and conventional angiography was good for the anterior and posterior circulations despite a tendency toward overestimation of stenoses on MR angiograms. Clinically relevant stenoses and occlusions were correctly identified on 3D MR angiograms, providing good sensitivity and specificity. CONCLUSION: Contrast-enhanced 3D MR angiography is a promising tool for assessing arteriosclerotic lesions of supraaortic vessels. Further studies with larger groups are required to determine its value for patient care.

Adult↗
PubMed1998

[Learning disorders after ruptured aneurysms of the anterior communicating artery].

The aim of this study was to reevaluate short term and long term memory disorders after anterior communicating artery rupture, then to more specifically assess the importance and the role of forgetting, proactive and retroactive interferences, impaired memory for temporal order, attention disorders and dysexecutive syndrome, and finally MRI-defined brain lesions. Twenty one patients presenting with selective anterior brain injury, were assessed at the secondary and late post stroke phases. The short term memory analysis showed the digit span was reduced at the secondary stage, but that mean performances were preserved in the Peterson and Sternberg paradigms. Verbal and visuospatial learning in long term memory showed a severe deficit in free recall, chiefly serial, and associative recall. Recognition was mildly impaired at the secondary phase, and later normalized. A definite and lasting increase of proactive and retroactive interferences and an impairment in discriminating the temporal order of word presentations were observed. Amnesic impairment was relatively well correlated with forgetting, severity of interferences and temporal order amnesia, so as with disorders of attention and executive functions (Wisconsin Card Sorting Test). However, intrusions in free recall and false recognitions were not clearly related with the dysexecutive syndrome. The severity of amnesia was associated with lesions of the left anterior cingulate cortex, and of the corpus callosum. These results suggest that these patients mainly had a deficit in information retrieval, mostly compromising long term memory, but also to a lesser degree short term memory. Forgetting, interferences and the dysexecutive syndrome probably play an important role in the decline of mnemonic performance, but do not clearly explain intrusions in recall and errors in recognition.

Aged↗
PubMed1997

[Cerebral fat embolism after closed leg injury].

A 21-year-old man sustained a closed fracture of the leg from an industrial accident, without associated head trauma. The orthopaedic treatment consisted of immediate immobilization by setting leg in plaster. Two hours after admission, the Glasgow coma scale score was 10. Four hours after admission he developed a coma (Glasgow coma scale score = 7) with repetitive seizures. No lesion was visible on cerebral CT scan. Chest X-ray was unremarkable. Petechiae on the anterior chest wall and abdomen with bilateral mydriasis occurred. Thrombocytopenia with prothrombine time increase were observed. Magnetic resonance imaging, 27 hours after admission, showed high-intensity areas on T2 weighted views due to fat embolism. Retinal haemorrhages were observed. The bronchoalveolar lavage showing fat staining of tracheal aspirates confirmed the diagnosis of fat embolism. This case report emphasizes the possibility of predominant neurologic manifestations of a fat embolism and the diagnostic help of cerebral magnetic resonance imaging.

Accidents, Occupational↗
PubMed1997

Preexisting dementia in stroke patients. Baseline frequency, associated factors, and outcome.

BACKGROUND AND PURPOSE: The link between stroke and degenerative dementia, especially Alzheimer's disease, is closer than expected by chance. Dementia after stroke may be due to the cumulative effect of vascular and degenerative changes. The prevalence of dementia just before stroke onset remains unsettled. The aim of this study was to determine the frequency of preexisting dementia in stroke patients, associated factors, and consequences on outcome. METHODS: We evaluated the cognitive functioning prior to stroke in 202 consecutive patients with ischemic or hemorrhagic stroke by means of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). We classified in the dementia group patients with IQCODE scores of 104 or more. Six months after stroke onset, survivors underwent a battery of neuropsychological tests. RESULTS: Thirty-three patients were demented before stroke (16.3%; 95% confidence interval, 11.2 to 21.4). There was no diagnosis of dementia in 32 of these 33 patients. We determined by logistic regression analysis that female sex, family dementia, leukoaraiosis, and cerebral atrophy are independently associated with prestroke dementia. All survivors who had IQCODE scores of 104 or more at the acute stage met criteria for dementia 6 months later. CONCLUSIONS: Our study showed that one sixth of stroke patients have preexisting dementia. Therefore, some patients with so-called "poststroke dementia" probably had unrecognized preexisting dementia.

Adult↗
PubMed1997

Novel decision making in patients with prefrontal or posterior brain damage.

Patients with lesions of the frontal lobes experience greater difficulties in performing nonroutine tasks, but their ability to cope with novel situations has not been studied. We assessed novel and previously practiced decisions in normal subjects and patients with frontal or posterior brain damage using a unimanual two-choice response time test. Patients with frontal damage had a dramatic impairment on novel decision, whereas practiced decision was normal. Relative Judgment Theory analysis suggested that the basic disorder concerns the ability to create internal referents that are determined from instructions and are subsequently required to associate the current stimulus with the appropriate response. The results of the study suggest that the prefrontal cortex is critical for novel decision making and that it operates mainly at the stage of creation of internal referents that associate some subsequent event with the selection of appropriate processing. This basic disorder may underlie some behavioral changes such as apathy and difficulty on tests that are sensitive to frontal damage.

Adult↗
PubMed1997

[Retrograde memory after rupture of aneurysms of the anterior communicating artery].

The aim of this study was to investigate deficits of retrograde memory, semantic, autobiographical, and for famous events, associated with prefrontal, cingulate and subcortical lesions resulting from anterior communicating artery rupture. Analyses were performed during the secondary phase post-stroke in 16 patients, and performances were compared to those of an equivalent number of matched control subjects. Semantic investigations revealed a significant deficit in each task using evocation, more especially categorical and literal evocations, and the verbal subtests of the WAIS-R: vocabulary, information, comprehension, and similarities. Furthermore, the capacity to categories was preserved. The Crovitz paradigm, which evaluated the autobiographical memory showed a severe deficit in the evocation of events associated with a precise context in place and moreover in time, with a clear tendency to produce semantic responses, but without significant increase in confabulations. The questionnaire on famous events (1936-1985) did not document deficit in recognition and recall. Furthermore, the patients disorder was more severe in learning new information. Memory disorders were best explained by the severity of lesions in the medio-basal frontal and cingulate cortices, but also by the subcortical injury. Significant correlations were observed between the retrograde memory performance and "frontal" tasks, more especially the WCST; however, similar relations were also documented between learning new information and "frontal" performance. These data suggest that retrograde amnesia results from a selective impairment in accessing old memory representations, and that cognitive processes more specifically altered have tight relations with the capacity to organize the search and to shift.

Adult↗
PubMed1996

Divided and focused attention in patients with lesion of the prefrontal cortex.

Despite the common claim of attention disorders in patients with frontal lobe lesion, attention has been poorly investigated and its contribution to behavioral changes has not been studied. The aim of this study was to assess divided (Experiment I) and focused attention (Experiment II) in patients with prefrontal damage. The study used simple detection tests measuring reaction times (RT) to successive stimuli of one modality and of randomly varying modalities (divided attention) and Go No-Go tests (focused attention). Experiment I showed that RT difference between patients and controls increased when stimuli modality was uncertain, a result we attributed to a deficit of divided attention. Experiment II showed that patients remained sensitive to irrelevant stimuli, demonstrating their inability to focus attention. The prominent behavioral change in patients consisted of increased distractibility which was correlated with divided and focused attention deficits. Finally, the presence on magnetic resonance imaging of a left lesion in the superior part of the prefrontal cortex and in the head of the caudate nucleus was the best predictor of attention disorders. In conclusion, this study shows that patients with a prefrontal lesion suffer from divided and focused attention deficits that correspond to behavioral changes.

Adult↗
PubMed1996

Binary choice in patients with prefrontal or posterior brain damage. A relative judgement theory analysis.

Binary choice task has been poorly evaluated in patients with focal brain damage. We assessed the decision process in normal subjects and patients with frontal or posterior brain damage using a unimanual two-choice response time (CRT) paradigm. The decision was manipulated by varying the response probability and parameters were analysed with the relative judgement theory. The results suggest that the binary decision process is spared in patients with focal lesions and that their longer CRT is mainly related to slowing the perceptual or motor stages. The prominent role of the left hemisphere in binary choice received support.

Adult↗
PubMed1996

Non-spatial attention disorders in patients with frontal or posterior brain damage.

The few studies that have looked at attention in patients with brain damage suggest a prominent role for the frontal lobe in nonspatial attentional control. However, the studies usually focus on one variety of attention and do not address the nature of the alteration of attention. In addition, the behavioural consequences of nonspatial attentional deficit remain unknown. The aim of this study was to evaluate the role of focal brain damage on divided and focused attention and the relationship between attention disorders and behavioural changes. The study group consisted of patients with lesions of the prefrontal and posterior cortices and control subjects. The assessment of attention used reaction time tests that evaluated the ability to divide attention between two sources (detection tests) and to focus attention on one source (Go/No-Go Tests). The response retardation of the 'frontal' group became more pronounced as the number of sources to be monitored increased, suggesting the presence of a deficit of divided attention. Focused attention deficit was demonstrated in the 'frontal' group by the more frequent responses to irrelevant stimuli on Go/No-Go Tests. Both focused and divided attention deficits were prominent when the lesion included the left dorsolateral prefrontal cortex and the caudate nucleus. Selective deficit of divided or focused attention was shown in a few patients. Finally, the clinically assessed distractibility was related to disorders of divided and focused attention. This study provides additional evidence for the prominent role of the frontal lobe in nonspatial attention regulation and shows that it also operates in elementary perceptuomotor processes. The relationship between distractibility and attention indexes supports the idea that attention disorders may have a functional counterpart that is clinically assessable. The demonstration of selective deficit of divided or focused attention suggests that nonspatial attention depends upon different mechanisms and that it is not an undifferentiated general purpose mechanism. Further studies addressing the nature of the interactions between attentional mechanisms and other cognitive processes are required.

Adult↗
PubMed1996

Risk factors and leukoaraiosis in stroke patients.

OBJECTIVES: Although leukoaraosis (LA) is a common CT findings, its pathogenesis remains debated: if small-artery pathology may explain in some cases white matter changes, many other factors, such as hemodynamic perturbations, might also lead to LA. To test these hypothesis, we determined the types of cerebrovascular risk factors associated with leukoaraosis in consecutive patients with acute cerebrovascular event. PATIENTS AND METHODS: Using CT-scans, we prospectively studied in 610 patients consecutively admitted for an acute cerebral event, the relation between LA and the following cerebrovascular risk factors: age, sex, arterial hypertension, diabetes mellitus, hyperlipemia, alcohol consumption, birth contraceptive pills, previous transient ischemic attack or stroke, migraine, atrial fibrillation, valvulopathy, coronaropathy, left ventricular hypertrophy, stenosis of the internal carotid artery, by means of a multiple linear regression. Relation with cerebral atrophy was also evaluated. RESULTS: We found LA scores to depend on increasing age (p = 0.0001), female sex (p = 0.0146), history of stroke or TIA (p = 0.0051), history or current atrial fibrillation (p = 0.0083), increasing cerebral atrophy score (p = 0.0001), absence of hyperlipemia (p = 0.0003) and absence of alcohol consumption higher than 300 g/week (p = 0.0398). CONCLUSION: Our findings do not support the hypothesis that, in stroke patients, LA share similar risk factors than small-vessel disease; other cerebrovascular risk factors may also contribute to LA, perhaps because of decreased cerebral blood flow.

Adolescent↗
PubMed1996

Helical CT for the diagnosis of extracranial internal carotid artery dissection.

BACKGROUND AND PURPOSE: We attempted to evaluate the sensitivity of helical CT for the diagnosis of extracranial internal carotid artery (ICA) dissection. METHODS: Sixteen consecutive patients with 18 angiographically confirmed extracranial ICA dissections were studied with a helical CT protocol with large-volume acquisition and thin axial slice reconstructions. A control group including normal and atherosclerotic ICAs was formed for comparison, and a blind interpretation of CT images was made by two observers. We evaluated the presence of stenosis, eccentric lumen, mural thickening, aneurysm, occlusion, and annular contrast enhancement. When the artery seemed to be occluded, we measured the external diameter of the ICA (1) on the occluded side, at its upper portion and most enlarged level, (2) at its lower portion, beyond the bulb, and (3) on the contralateral side, at is upper portion. RESULTS: Interobserver agreement was good except for the presence of annular contrast enhancement. In the stenotic dissection group (n=12), the presence of a narrowed eccentric lumen at the upper portion of the ICA on axial CT images was classified correctly in all cases (sensitivity, 100%; specificity, 100%). An arterial wall thickening was seen in all cases of dissection but also in three cases of the control group. In the occlusive dissection group (n=6), the enlargement of the dissected artery was the best criterion (sensitivity, 100%, specificity, 100%) for occlusive dissection. CONCLUSIONS: Helical CT seems to be a reliable method for evaluating extracranial ICA dissection. The analysis of the residual arterial lumen and the measurement of the external diameter of the carotid artery were the best criteria for the diagnosis. Further studies with larger groups are required to determine whether ICA dissections might be diagnosed using helical CT as a first procedure.

Adult↗