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Biomedical subjects

M G Bousser

Publications and source records attributed to M G Bousser.

At least 253 records · Page 14Linked to original sources
PubMed1983

[Positron emission tomography in the physiopathological study of cerebral ischemia in man].

The development of positron emission tomography now allows the local study of cerebral blood flow, oxygen consumption and glucose utilization in ischemic stroke patients. In recent cerebral infarction, a disruption of the normal couple between flow and metabolism is almost constantly observed: in the first few days cerebral blood flow is either inadequate (persistent ischemia) or over-abundant ("luxury perfusion"), whereas a late "luxury perfusion" is almost constant within the necrotic area between the 10th and the 40th day. Threshold values for cerebral blood flow and oxygen consumption that are ultimately associated with necrosis or tissue integrity have been determined. A metabolic depression without C.T. Scan counterpart has been observed in various brain structures remote from the infarcted area per se. Lastly, the hemodynamic and metabolic effects the superficial-temporal-middle-cerebral-artery anastomosis have been studied.

Brain Ischemia↗
PubMed1983

Coupling between regional blood flow and oxygen utilization in the normal human brain. A study with positron tomography and oxygen 15.

Using the oxygen 15 continuous-inhalation technique and positron emission tomography (PET), the regional cerebral blood flow (rCBF), oxygen extraction fraction (rOEF) and oxygen utilization (rCMRO2) were measured in 19 control subjects. The rCBF and rCMRO2 values, computed for small regions of interest (ROI), were within accepted normal ranges. Larger, more convenient ROI provided values for gray and white matter regions that were, respectively, lower and higher than those found using small ROI. The rOEF values were not affected by the ROI size, but seemed to slightly overestimate real OEF. These findings may be explained by (1) the partial volume effect, and (2) some limitations of the 15O steady state model. The 15O-PET technique therefore provides representative but clinically useful physiological indexes. In addition, our study demonstrated the normal coupling between local oxygen supply and demand.

Adult↗
PubMed1983

Tissue acid-base balance and oxygen metabolism in human cerebral infarction studied with positron emission tomography.

Nine patients who had suffered strokes were examined between 10 and 34 days after onset using positron emission tomography. DMO labeled with carbon 11 was used to evaluate brain acid-base balance, and the oxygen-15 inhalation technique was used to measure regional cerebral blood flow, the oxygen extraction fraction, and cerebral metabolic rate for oxygen. [11C]DMO concentration and oxygen metabolism variables were measured in the infarcted area and in the symmetrical region in the contralateral cerebral hemisphere. [11C]DMO concentration was found to be unchanged or slightly increased in five cases and markedly increased in four cases. The apparent increase in tissue pH can be explained by the presence of a large extracellular fluid space with a pH nearly identical to that of brain plasma, or by an increase in intracellular pH, or by both phenomena. The change in [11C]DMO concentration in the infarcted area relative to that in the normal tissue was independent of the change in blood flow. Cerebral metabolic rate for oxygen was decreased in all cases. The increase in [11C]DMO concentration in the infarcted area was linearly correlated with the decrease in the oxygen extraction fraction in the same region; that is, it was correlated with the occurrence of perfusion in excess of metabolic demand. The overabundant local perfusion could play a role in the decreased H+ content.

Acid-Base Equilibrium↗
PubMed1983

[Role of antiplatelet agents in the prevention of cerebral ischemic accidents].

This is a critical review of controlled therapeutic trials concerned with the use of anti-platelet agents in the prevention of cerebral ischaemic accidents due to atherosclerosis (CIADA). Amongst the 4 substances studied in 9 trials, dipyridamole, clofibrate, sulfinpyrazone and aspirin, only aspirin at the dose of 1 g brought about a statistically significant reduction in the risk of cerebral infarction and death in patients who had suffered an initial transient or rapidly regressive cerebral ischaemic accident. Nevertheless, this preventive action was seen in only one of the 5 studies devoted to aspirin and was found only in men, in particular where there was no history of diabetes or myocardial infarction. Although encouraging, this result requires confirmation by other studies before any definite conclusion is drawn as to the efficacy of aspirin in the secondary prevention of CIADA.

Adult↗
PubMed1983

[The A.I.C.L.A. controlled cooperative trial. Secondary prevention of cerebral ischemic accidents due to atherosclerosis by aspirin and dipyridamole. 3: Results].

As decided in the protocol, the AICLA study ended when all the 604 patients had completed a follow up of three years. Adhesion to the protocol and drug compliance were excellent. Side effects, particularly peptic ulcers and bleedings of various origins were more frequent in the 2 treatment groups containing aspirin. The number of fatal and non fatal cerebral infarction was 31 in the P group, 17 in the ASA group, and 18 in the ASA + D group. Taking into account the duration of follow up for each patient, these figures correspond to cummulate rates of 18 p. 100 in the P group and 10.5 p. 100 in the 2 others. Analysis with the Mantel Method showed: 1 - a difference at the 6 p. 100 level between the 3 groups and between P an AD; 2 - A difference at the 5 p. 100 level between P and A; 3 - No difference between A and AD; 4 - A difference at the 2 p. 100 level between the P group and the two treated groups taken together. Among other diseases occurring during the trial, the only significant difference concerned myocardial infarction, less frequent in the 2 treated groups (p less than 0.05). Subgroup analysis failed to show a significant sex difference in the efficacy of aspirin. It is concluded that, in patients such as those defined in the protocol, Aspirin (1 g) has a significant beneficial effect in the secondary prevention of atherothrombotic cerebral infarction.

Aspirin↗
PubMed1983

[Cerebral blood flow and oxygen extraction in lacunar hemiplegia. Semi-quantitative study using oxygen 15 and emission tomography].

The oxygen 15 non invasive continuous inhalation technique coupled with positron emission tomography (P.E.T.) allows the local study of cerebral blood flow and oxygen metabolism. Recent P.E.T. studies have demonstrated the frequent occurrence of widespread metabolic depression remote from the site of middle cerebral artery territory infarct per se, especially over the cortical mantle and thalamus ipsilaterally, and over the cerebellar hemisphere contralaterally. These phenomena have been taken as indicative of transneural depression (i.e. diaschisis). We thought it interesting to study the possible occurrence of such abnormalities in patients with lacunar syndromes. We have applied the (15)0 technique to six patients (2 with pure motor hemiplegia, 4 with ataxic hemiparesis) for whom no large causal ischemic lesion could be demonstrated on CT scans; in only one patient was a lacunar lesion, presumably responsible for the clinical deficit demonstrated. Compared to a set of 19 patients without brain disease, the semi-quantitative results (analyzed in terms of asymmetry indices between homologous brain regions) in our patients did not disclose any pathophysiologically significant abnormality. More specifically, no evidence of physiological dysfunction similar to that reported in internal carotid artery territory infarcts, was detected over the cerebral or cerebellar cortices. These findings are commented upon in view of the presumably small size and the uncertain topography of the causal lesion.

Aged↗
PubMed1982

[Controlled therapeutic trials in migraine: methodology and results].

This review first brings justification to performing controlled therapeutic trials in migraine. It then describes the organisation of a prophylactic trial; the criteria for inclusion and exclusion, the various possible protocols, and the data analysis are discussed, while the many difficulties and pitfalls brought about by the natural characteristics of the disease are stressed. Some limitations inherent to prophylactic trials and to migraine when interpreting the results are emphasized. The findings of the prophylactic trials published to date are briefly summarized in three tables; the results indicate both the usefulness and the validity of this methodological approach in migraine. The main features and specific difficulties of the controlled trials of drugs the treatment of migraine attacks are briefly commented, and the literature review is broadly tabulated. Lastly, a brief account of the problems involved in controlled trials of non-chemical migraine therapy is given. Despite their numerous limitations, the controlled trials have considerably clarified the therapeutic approach of migraine.

Clinical Trials as Topic↗
PubMed1982

Noninvasive measurement of blood flow, oxygen consumption, and glucose utilization in the same brain regions in man by positron emission tomography: concise communication.

Local cerebral blood flow (CBF), oxygen consumption (CMRO2), and glucose utilization (CMR-Glc) have been measured in three patients by positron emission tomography (PET), together with continuous inhalation of oxygen-15-labeled gases and i.v. injection of [18F]fluoro-2-deoxy-D-glucose. In normal brain, the close local coupling between CBF and CMR-Glc, and that between CMRO2 and CMR-Glc, were well demonstrated. The coupling held for the asymptomatic areas and for parts of the affected hemispheres in two patients with cerebral ischemia. In one patient the CBF/CMR-Glc couple, but not the CMRO2/CMR-Glc couple, was disrupted in the acute ischemic core. This preliminary work demonstrates the local quantification of these important functional parameters, and indicates the potential usefulness of studying their pathophysiological interrelationship in brain disease.

Aged↗
PubMed1982

[A 15oxygen positron study of relative local perfusion and oxygen extraction of the brain in lacunar hemiparesis (author's transl)].

The oxygen-15 non-invasive continuous inhalation technique coupled with positron emission tomography (PET) allows the local study of cerebral blood flow and oxygen metabolism. Recent PET studied have demonstrated the frequent occurrence of widespread metabolic depression remote from the site of middle cerebral artery territory infarct per se, especially over the cortical mantle and thalamus ipsilaterally, and over the cerebellar hemisphere contralaterally. These phenomena have been taken as indicative of a transneural depression (i.e. diaschisis). We thought interesting to study the possible occurrence of such abnormalities in patients with lacunar syndromes. We have applied the 15O technique to seven patients (2 with pure motor hemiplegia, 5 with ataxic hemiparesis) in whom no large causal ischemic lesion could be demonstrated on CT Scans; in only one patient was a lacunar lesion, presumably responsible for the clinical deficit, evidenced. Compared to a set of 19 patients without brain disease, the semi-quantitative results (analyzed in terms of asymmetry indices between homologous brain regions) in our patients did not disclose any pathophysiologically significant abnormality. More specifically, no evidence of physiological dysfunction similar to that reported in internal carotid artery territory infarcts, was detected over the cerebral or the cerebellar cortices. These original findings are commented upon in view of the presumably small size and the uncertain topography of the causal lesion.

Aged↗
PubMed1982

[Controlled cooperative trial. Secondary prevention of atherosclerosis-related cerebral ischemic accidents by aspirin dipyridamole. 2: Description of subjects at the beginning of the trial].

This paper is the second devoted to the controlled trial "A.I.C.L.A." comparing aspirin, aspirin + dipyridamole and placebo in the secondary prevention of athero-thrombotic cerebral ischaemic events. It presents the description and distribution of baseline characteristics at entry. Six hundred and four patients (men: 70 p. 100, mean age : 63) were entered. Risk factors were distributed as follows: arterial hypertension: 63 p. 100, Diabetes: 24 p. 100, High blood lipids: 26 p. 100, high uric acid: 20 p. 100, hematocrit greater than 46 p. 100: 34 p. 100, cigarette smoking: 64 p. 100, angina pectoris and myocardial infarction: 15 p. 100, peripheral vascular disease: 7 p. 100, 37 p. 100 of patients had a stroke prior to entry. The ischemic event at entry occurred not more than one year prior to randomization and less than 3 months in 77 p. 100. It was much more often a completed stroke (84 p. 100) than a transient ischaemic attack (16 p. 100) and was referrable either to the carotid (46 p. 100) or the vertebrobasilar circulation (50 p. 100). On the whole patients are older and strokes more severe than in other similar studies. Randomization produced remarkably comparable treatment groups since almost no significant difference was observed between the 3 groups.

Aged↗
PubMed1982

[Neurologic manifestations of Behcet's disease. 24 cases].

Dominant symptoms in 24 patients with neurological manifestations of Behçet's disease were meningo-encephalitis (13 cases), febrile meningeal syndrome (3 cases), intracranial hypertension (6 cases), polyneuritis of the lower limbs (1 case), and isolated retrobulbar ocular neuritis (1 case). Several classical notions concerning the "Neuro-Behçet" meningo-encephalitis were confirmed: the frequency of central motor lesions (33 p. cent), cerebrospinal fluid alterations (anomalies in 100 p. 100 of cases in the initial stage), and the often unfavorable course (40 p. cent). An unusual finding in this series was the frequency of cerebral veins thrombosis (4 certain and 2 probable). These could be differentiated from meningo-encephalitis by their symptomatology, predominantly that of intracranial hypertension, and by their course: often the first disorder to appear in the course of Behçet's disease, they followed a favorable neurological course but were constantly complicated by other vascular manifestations, usually phlebitis. It is suggested that a long-term anticoagulant treatment should be associated with corticoid therapy in these forms.

Adult↗
PubMed1981

[Migraine].

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Adolescent↗