Biomedical subjects

H L Lagreze

Publications and source records attributed to H L Lagreze.

7 recordsLinked to original sources

PubMed1993

Treatment of multiple sclerosis with 15 +/- deoxyspergualin. Design of a controlled study with close MRI-monitoring.

The rationale and design of a prospective randomized double blind study of 15 +/- Deoxyspergualin in the treatment of Multiple Sclerosis are presented. The study was started in autumn 1992 and will include more than 200 patients who will be randomized either to DSG low dose or DSG high dose or placebo. Average number of contrast enhancing lesions in monthly cranial MRIs during the first six months of treatment and change in EDSS at the end of the two-year study period will be the main efficacy parameters.

Adolescent↗

PubMed1989

Evidence for transhemispheric diaschisis in unilateral stroke.

Nineteen patients with strictly unilateral ischemic stroke as determined by clinical examination, computed tomography, magnetic resonance imaging, and standard angiography underwent cerebral blood flow (CBF) analysis using fluorine 18 fluoromethane and positron emission tomography. Mean flow values for averaged hemispheric, infarct, and homologous contralateral regions of interest (ROIs) were determined. All patient CBF values were significantly below comparable CBF ROIs in neurologically normal controls using Wilcoxon's two-sample rank testing. Multiple regression analysis disclosed a significant correlation between contralateral CBF are both localized CBF in the infarct ROI and patient age. Correlations between contralateral CBF and dependency score or severity of neurologic deficit at time of positron emission tomography, expired PCO2, mean arterial blood pressure, serum glucose or hematocrit, risk factor score, and number of days studied after stroke were not statistically significant. Although we did not identify the biologic mechanisms involved, we conclude that CBF reduction contralateral to a strictly unilateral ischemic infarction is due to a combination of aging and transhemispheric diaschisis.

Adult↗

PubMed1989

Cerebral vasocapacitance and TIAs.

We report the vasocapacitance of the cerebral circulation, as determined by cerebral blood flow reactivity to induced hypercapnia using fluoromethane positron emission tomography, in 32 patients with unilateral anterior circulation transient ischemic attacks. A hemodynamic subset of eight patients, defined based on exertional, positional, orthostatic, or cardiac dysrhythmic induction of symptomatology, is characterized by multiple (median, 4.5 attacks per patient), brief (median, 2.5 minutes per attack), continued episodes of hemispheric ischemia including focal limb shaking. Symptomatic middle cerebral artery flow territories show significantly lower (p less than 0.04) and more asymmetric (p = 0.036) vasodilatory responses in the hemodynamic subset. Although ipsilateral internal carotid artery occlusion is more prevalent in the hemodynamic subset, the features of age, mean arterial blood pressure, carbon dioxide values, serum glucose, serum hematocrit, and number or type of risk factors do not differ significantly between groups. These studies of vasocapacitance help validate clinical criteria for cerebral hemodynamic events with an objective physiologic measurement.

Cerebral Angiography↗

PubMed1988

Large subcortical hemispheric infarctions. Presentation and prognosis.

A specific form of large subcortical hemispheric infarction on computed tomography was identified in 24 of 2198 (1%) stroke registry patients. Combined with 13 cases from earlier literature reports, a characteristic neurologic picture developed. Severe face plus arm plus leg weakness at onset (76%), corticallike features of aphasia and/or contralateral neglect (68%), and premonitory transient ischemic attacks (24%) were frequent. Twenty-two patients (59%) had large vessel arterial occlusive disease. Eight patients (22%) had primary embolic occlusion in the middle cerebral artery territory. During an average follow-up of 16 months, five patients (14%) suffered recurrent stroke or death. The clinical presentation and prognostic features of this distinct stroke subtype are described.

Adult↗

PubMed1988

Pitfalls of regional cerebral blood flow analysis in cerebrovascular disease.

In 20 patients with unilateral cerebrovascular disease, regional cerebral blood flow (rCBF) was measured by F-18-fluoromethane inhalation and positron emission tomography (PET). The purpose was to study various strategies of rCBF data analysis that are currently used in SPECT and PET. Methods of quantitative data analysis standardize rCBF values relative to an intraindividual reference, and thus create ratios as estimators of rCBF in the ischemic regions-of-interest (ROI). These ratios were compared as well as the absolute rCBF values in the ischemic ROI graphically and by Spearman's rank correlation coefficient (r). The results demonstrated that previously reported methods of data analysis failed to represent rCBF in the ischemic ROI; r values were 0.467, -0.406, -0.453, and 0.329, respectively (N.S.). This failure was due to a more widespread reduction of rCBF even in patients with minimal ischemic deficits. In conclusion, previously reported strategies of rCBF analysis based on intraindividual standardization should not be used in patients with cerebrovascular disease since they may produce misleading results.

Brain Ischemia↗

PubMed1988

Cerebral perfusion reserve indexes determined by fluoromethane positron emission scanning.

An index of cerebral perfusion reserve (RES%), defined as the percent change of regional cerebral blood flow over baseline per mm Hg of end-tidal CO2 tension, was determined for each middle cerebral artery (MCA) territory in patients with unilateral carotid distribution transient ischemic attacks or minor cerebrovascular accidents and was compared with that of age-matched, neurologically normal volunteers. Vasodilator responses to induced hypercapnia were tested during inhalation of 5% CO2 in 95% O2 while regional cerebral blood flow was measured by fluoromethane inhalation positron emission tomography. Mean RES% for 24 normal MCA territories was 5.2 +/- 0.8%. Mean RES% for 15 patient nonischemic MCA territories was 3.8 +/- 1.3% and for 15 ischemic MCA territories was 2.8 +/- 1.9% (both p less than 0.001). Individual RES% values and symmetry ratios between ischemic and nonischemic regions were also determined and compared with angiographic data. Areas of diminished, asymmetric, or paradoxical (two patients) CO2 reactivity appear to correspond to areas of compensatory vasodilation. We found this technique to be a safe and reproducible method for defining and recording localized areas of cerebral tissue at apparent risk for hemodynamically related damage.

Carbon Dioxide↗

PubMed1988

Noninvasive testing of cerebral perfusion reserve prior to coronary artery bypass graft surgery.

Cerebral perfusion reserve testing using fluorine-18-fluoromethane and positron emission tomographic brain scanning to define cerebral blood flow abnormalities was performed in 5 patients being considered for combined coronary and carotid reconstructive surgery. Blood flow testing during normocapnia and following hypercapnia was utilized in these patients to determine the hemodynamic significance of known extracranial carotid artery occlusive lesions. Reserve diminution in 2 of these patients prompted combined surgery, whereas normal reserve values in the other 3 prompted coronary surgery alone. Results obtained in this preliminary series show how preoperative noninvasive testing of cerebral perfusion reserve adds to the diagnostic evaluation of patients with widespread vascular disease.

Brain↗