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Biomedical subjects

A Bès

Publications and source records attributed to A Bès.

At least 19 recordsLinked to original sources
PubMed1995

Asymptomatic cerebral embolic signals in patients with carotid stenosis. Correlation with appearance of plaque ulceration on angiography.

BACKGROUND AND PURPOSE: Asymptomatic cerebral emboli may be detected in patients with carotid stenosis by transcranial Doppler ultrasonography of the middle cerebral artery (MCA). The aim of this study was to determine the angiographic correlates of such embolic signals. METHODS: Doppler signals from 48 MCAs in 26 patients with carotid stenosis that was either symptomatic (n = 20) or asymptomatic (n = 6) were recorded for 40 minutes. The grade of carotid stenosis and the ulcerated or nonulcerated appearance of the plaque were assessed using the criteria of the North American Symptomatic Carotid Endarterectomy Trial. RESULTS: Embolic signals were detected in 8 MCAs from 7 patients; 4 (50%) of these MCAs were clinically symptomatic compared with 16 (40%) without embolic signal. Although there was a trend toward more severe stenosis in the cases with embolic signals, this was not significant (mean +/- SD, 67 +/- 29% versus 55 +/- 36%). In contrast, an image of ulceration was found on ipsilateral carotid angiography in 5 cases (63%) with embolic signals and in only 9 cases (23%) without embolic signals (odds ratio, 5.74; 95% confidence interval, 1.15 to 28.79, by multivariate regression analysis). CONCLUSIONS: This study demonstrates that the occurrence of embolic signals in patients with carotid stenosis is associated with the appearance of plaque ulceration on angiography.

Carotid Arteries↗
PubMed1994

The functional anatomy of attention in humans: cerebral blood flow changes induced by reading, naming, and the Stroop effect.

We measured changes in regional cerebral blood flow (rCBF) induced by reading, naming, and the Stroop effect in 12 right-handed normal volunteers. rCBF was quantified with a single-photon emission computerized tomograph after intravenous injection of 133Xe. Data were analyzed using predetermined regions of interest and a linear model. A significant relative activation was revealed in the right superior mesial frontal region during the Stroop effect.

Adult↗
PubMed1994

[Effects of captopril on the cerebral blood flow in the hypertensive aged subjects].

Cerebral blood flow (CBF) was measured in 13 subjects (4 men and 9 women, mean age +/- SD = 63 +/- 7) with moderate, uncomplicated and untreated hypertension and 11 normotensive subjects (6 men and 5 women, mean age +/- SD = 66 +/- 5). A second CBF measurement was performed in hypertensive subjects after a 60 days randomized double blind treatment with either captopril, 75 mg a day (n = 8) or placebo (n = 5). CBF was quantified using the 133Xe inhalation technic and 16 stationary detectors by hemisphere. Comparison of CBF values between hypertensive subjects before treatment and normotensive subjects demonstrated a decrease of CBF in the hypertensive group (49 +/- 9 vs 72 +/- 14 ml/100 g/min; p < 0.001). After the trial the results in the captopril group showed a significant fall in systolic (p < 0.001) and diastolic (p < 0.05) blood pressure and a significant increase in CBF (60 +/- 14 vs 49 +/- 11 ml/100 g/min; p < 0.05). In the placebo group there was no change in blood pressure and CBF (Table). [Table; see text] Our results demonstrate a decrease in CBF of uncomplicated and untreated elderly hypertensive subjects. This decrease is reversible under chronic treatment with captopril.

Aged↗
PubMed1986

Pharmacological exploration of dopamine hypersensitivity in migraine patients.

Patients with migraine show a hypersensitivity to dopamine or its agonists. One of these, piribedil, was administered as 0.1 mg/kg intravenously over 30 min to subjects with either migraine or other types of headache. This test provoked in migraine patients an increase of the cerebral blood flow and the peripheral signs of dopamine hypersensitivity:- nausea or vomiting and a rapid fall in blood pressure. In contrast, in those subjects with chronic non-migrainous headache, the administration of piribedil had no effect. The piribedil test appears to possess good specificity vis à vis migraine, enabling a differential diagnosis from atypical periodic headache, a condition difficult to consider as migraine or psychogenic headache on clinical grounds alone.

Cerebrovascular Circulation↗
PubMed1985

[Cerebral blood flow and meningeal hemorrhage. An aid to the surgical decision].

One hundred and eleven measurements of cerebral blood flow (C.B.F.) were performed using the Xenon 133 inhalation method in 80 cases of spontaneous subarachnoid hemorrhage of which 59 were due to ruptured aneurysms. This method is non-traumatic, reproducible and dependable. A correlation was found between clinical condition and C.B.F. values, but in a number of cases which cannot be dismissed, very low mean C.B.F. values or ischemic foci were revealed where clinical state gave no indication. A poor correlation appeared between vasospasm seen by angiography and ischemic foci detected by isotopic technique. Patients' age influenced C.B.F. values but not clinical evolution. No correlation was found between C.B.F. values and cisternal blood seen on CT scan. C.B.F. values, measured in the first two weeks of illness, were significantly higher in those patients having favorable outcome, whatever their clinical state at the time of C.B.F. measurement (comas excluded). The figure of 60 ml/100 g/min for mean cortical flow seemed to be a critical level below which the risk of complication was greater. Below this level or in cases or ischemic foci, surgery was delayed. Thus, C.B.F. measurement promises to be a valuable prognostic tool, playing an important role in the therapeutic strategy for this type of patients.

Adult↗
PubMed1984

[Central pontine myelinolysis with regressive development and x-ray computed tomographic interpretation].

A 68 year-old woman presented after rapid correction of a hyponatremia a clinical picture suggestive of central pontine myelinolysis. Clinical disorders regressed but serial CT scans showed the late development of a central pontine low density area which persisted for several months. Such a lack of correlation between clinical and CT scan data has been previously reported. On the present case the demyelination lesions appeared to have resulted principally from the rapid increase of natremia.

Aged↗
PubMed1983

[Recurrent cerebral ischaemic attacks in young subjects. Arteriolar dysplasia or early atheroma?].

The case of a 33-year old woman with recurrent cerebral and peripheral ischaemic attacks is reported and the difficult nosological problem of juvenile ischaemia is discussed. Thromboangiitis obliterans (Buerger's disease) was excluded by morphological studies of finger tips, temporal artery and dermis, which demonstrated arteriolar dysplasia and premature aging of the connective tissue. A diagnosis of "juvenile atheroma" may be considered in view of the dyslipidaemia and increase in skin cholesterol and apoprotein B concentrations observed. A review of the literature, together with the biochemical and histological findings in this patient, suggests that ischaemic attacks, dysplasia of small vessels and serum dyslipidaemia reflected in the dermis are all manifestations of early atheroma.

Adult↗
PubMed1983

Cerebral blood flow studied by Xenon-133 inhalation technique in parkinsonism: loss of hyperfrontal pattern.

Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of 133Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid 133Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the "hyperfrontal distribution" in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group.

Adult↗
PubMed1983

[Value of the piribedil test in diagnosing migraine. Apropos of 150 cases].

Patients with migraine show a hypersensitivity to dopamine or its agonists. One of these, piribedil, was administered as 0,1 mg/kg intravenously over 30 minutes to 150 subjects with either migraine or other types of headache. This test provoked nausea and vomiting in 94 p. cent of patients with migraine, and a rapid fall in blood pressure requiring immediate interruption of the infusion in 69 p. cent. In contrast, in those subjects with chronic non-migrainous headache the administration of piribedil had no effect in 61 p. cent and provoked a fall in blood pressure in only 16 p. cent. The piribedil test appears to possess good specificity vis-à-vis migraine, enabling a differential diagnosis from atypical periodic headache, a condition difficult to consider as migrain or psychogenic headache on clinical grounds alone.

Adult↗
PubMed1983

[Atraumatic measurement of cerebral blood flow in spontaneous meningeal hemorrhage].

Cerebral blood flow (CBF) was measured 74 times in 50 patients with spontaneous meningeal hemorrhage using a method involving the inhalation of Xenon-133. The procedure is non-invasive, reproductible, and provides reliable results. Correlation was found between the clinical state and the CBF, but very low mean values for CBF, and ischemic foci associated with these values, were detected in cases where this could not be predicted from the clinical findings. No correlation existed between vasospasm seen on angiography and the ischemic foci revealed by the isotopic method. The age of patients had an influence on CBF values but not on the clinical course. Mean CBF levels during the first two weeks of the disease were significantly higher in patients in whom the course was uncomplicated, whatever their clinical condition (excluding coma) at the time of CBF measurement. A figure of 60 ml/100 g/min for gray substance blood flow appeared to be a threshold value, below which there was a greater risk of complications. Inversely, the outcome was favorable in all cases with a cortical blood flow superior to 70 ml. These findings suggest that cerebral blood flow measurement provides prognostic information which could be of marked assistance when deciding on appropriate therapy in such cases.

Adult↗
PubMed1982

[Dopaminergic hypersensitivity in migraine: a diagnostic test? (author's transl)].

A dopaminergic agonist, piribedil, was administered by intravenous infusion (0.1 mg/kg over 30 minutes) to 20 patients known to suffer from migraine and 20 subject free from any kind of headache. Neither changes in cerebral blood flow (CBF), as measured by the 33Xenon inhalation technique, nor peripheral side-effects were noted in the control group. Patients with migraine exhibited an 18 p. cent increase in CBF and a 32 p. cent decrease in mean arterial pressure and rapidly developed nausea severe enough to discontinue the infusion in most cases. Prior administration of domperidone, a neuroleptic drug which does not cross the blood-brain barrier, suppressed the nausea and fall in blood pressure but had no effect on the increase in CBF. This study confirms the existence of central and peripheral hypersensitivity to dopaminergic agents in patients with migraine. The piribedil test could be used to distinguish genuine migraine from ordinary cephalalgia in patients prone to headache.

Cerebrovascular Circulation↗
PubMed1982

Cerebral circulatory effects of a dopaminergic agonist (apomorphine) in the dog.

Dopaminergic influence upon cerebral circulation was studied in 12 adult mongrel dogs, local cerebral blood flow (lCBF) being measured by the microspheres method. The intravenous injection of apomorphine (0.1 mg/kg) produced heterogeneous effects on lCBF; an increase in lCBF reaching the level of statistical significance was observed in frontal and sensory motor cortices, whereas blood flow was not significantly altered in the other regions examined. When the animals are considered individually, a widespread response was generally observed. Local cerebral blood flow increased from 16% to 85% (depending on the regions examined) in 4 animals, and tended to decrease (particularly in the caudate nucleus) in the 8 others. These opposite effects cannot be related with changes in general metabolic or hemodynamic parameters (PaCO2, PaO2, pH, and arterial pressure). It is thus concluded that the effect of dopaminergic stimulation upon cerebral circulation is more complex than previously reported. These effects could only be partly mediated via vascular receptors and could be the result of modifications of the local metabolic level.

Animals↗
PubMed1978

[Peripheral neuropathy with cryoglobulinemia (author's transl)].

The author describe 2 personal observations of peripheral neuropathy with cryoglobulinemia and the 28 cases previously recorded are reviewed. The characteristics of the usually sensorimotor neuropathy are not specific. Nevertheless, the association with purpura, Raynaud's syndrome and leg ulcers and the inconstant aggravation of the symptoms with cold allow the diagnosis to be suspected on clinical grounds. Cryoglobulin can be recognised by immunoelectrophoresis and classified as type I monoclonal, types II and III mixed and polyclonal. Associated disease should be looked for; lymphocytic proliferation or auto-immune disease. If none is found a diagnosis of essential cryoglobulinemia can be made but with caution as cryoglobulinemia can precede by several years the appearance of associated disease.

Aged↗
PubMed1978

[Pseudo-tumoral softening of the cerebellum].

The author establish an onerall picture of cerebellar infarction with brain stem compression after reviewing 63 cases published in the literature and 4 personal observations. The frequency of this affection can be compared with that of cerebellar hematomas. Diagnosis is based on its predominance in males, the early age at which it appears, its rapid and typical onset, and the delayed signs of brain stem compression. Conventional neuroradiological procedures show an expanded cerebellar volume, and the scanner can specify the ischaemic nature of the lesion. As soon as changes in consciousness occur surgical decompression is necessary, first by external drainage of C.S.F. and later, if necessary, by direct access to the postdrior fossa.

Adult↗