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A Carolei

Publications and source records attributed to A Carolei.

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

Evaluation of potential factors affecting the measurement of cerebrovascular reactivity by near-infrared spectroscopy.

1.Near-infrared (IR) spectroscopy is based on the relative transparency of skin, skull and brain to the light in the near-IR region (700-1100 nm) and on the oxygen-dependent tissue absorption changes of haemoglobin.2. We evaluated the most relevant factors (reproducibility, venous return, age and sex) that might affect reliability of near-IR spectroscopy to test CO2 cerebrovascular reactivity.3.Thirty-four healthy volunteers were enrolled in the study. The protocol consisted of a 3-min baseline, a 3-min hypercapnia (5% CO2 in air) and a 2-min recovery. Transcranial Doppler sonography measurements were simultaneously performed. The CO2 reactivity test was repeated on 27 subjects after 1 h to assess reproducibility. CO2 reactivity was also evaluated at different body positions (supine, 35 degrees Trendelenburg and 35 degrees reverse Trendelenburg), and over a gradual increase of the inspired CO2.4. Changes in near-IR spectroscopy and transcranial Doppler sonography parameters were significantly correlated with variations of end-tidal CO2 (P<0.005). A significant correlation between the reactivity indexes of near-IR spectroscopy parameters and flow velocity was also found (P<0.01). A high reproducibility was also found for deoxyhaemoglobin (rI=0.76), oxyhaemoglobin (rI=0.68) and flow velocity (rI=0.60) reactivity indexes. No significant differences between the reactivity indexes of different body positions were found (P>0.05). The reactivity index of oxyhaemoglobin and deoxyhaemoglobin decreased (P<0.05) and increased (P<0.01) with age respectively.5. We found that near-IR spectroscopy is a reliable and reproducible method for the evaluation of cerebrovascular reactivity and might be considered, after appropriate validation, for the assessment of patients with cerebrovascular disease.

Adolescent↗
PubMed1997

Cerebrovascular reactivity in migraine during headache-free intervals.

Alterations of intracranial vessel tone have been implicated in the pathophysiology of migraine. The cerebrovascular reactivity was measured by means of transcranial Doppler in 60 migraine patients with (n = 30) or without aura (n = 30) during the headache-free interval and in 30 healthy controls. The vasomotor response was evaluated during hypercapnia induced by inhalation of a mixture of CO2 5% and O2 95% and during hypocapnia obtained after voluntary hyperventilation. To improve the power of the study in detecting possible abnormalities of cerebrovascular reactivity, two different measures were performed at 1 week intervals in migraine patients and controls. Reactivity index values during CO2 inhalation were significantly different (p = 0.01) among the three groups during the first and second measurements; in particular, lower values were found in patients suffering from migraine without aura with respect to controls (p < 0.05, Scheffé's test). Values of reactivity index obtained following induction of hypocapnia did not differ between migraine patients and controls (all p values > 0.05). Our data suggest a reduced vasodilatory response to hypercapnia of cerebral arterioles in patients suffering from migraine without aura with respect to controls that might be related to baseline arteriolar vasodilation.

Adult↗
PubMed1997

Oxidative stress and platelet responsiveness in migraine.

The aim of this study is to investigate whether oxidative stress may represent a pivotal determinant of the altered functional features of platelets in migraineurs during the headache-free period. Twenty-three patients with migraine with aura, free of attack, and 23 healthy volunteers were enrolled for the study. The involvement of an oxidative condition appears confirmed by the statistically significant increase (p < 0.001) of plasma levels of thiobarbituric acid-reactive substances which may be considered a marker for oxidative stress and themselves strong-pro-oxidants. Such oxidative status seems to induce in platelets of migraineurs increased membrane rigidity (p < 0.001), reduced cytosolic calcium in the resting condition and after thrombin stimulation (p < 0.001), and decreased aggregatory responses to ADP and collagen. These findings indicate that the "in vitro" anomalous platelet behavior in migraineurs, observed in headache-free periods, may be considered as the transient expression of the exhausted platelets to "in vivo" stimulation and probably related to an increased vulnerability to oxidative stress.

Adult↗
PubMed1997

High stroke incidence in the prospective community-based L'Aquila registry (1994-1998). First year's results.

BACKGROUND AND PURPOSE: Changes in stroke incidence are likely to occur as a consequence of aging of the population, but evidence for this hypothesis is lacking. METHODS: A prospective community-based registry of first-ever strokes (1994 to 1998) classified according to the International Classification of Diseases, 9th Revision (ICD-9) was established in the L'Aquila district, central Italy, with a total population of 297,838 (1991 census). Patients were identified by active monitoring of multiple sources, including general practitioners. RESULTS: In 1994, 819 patients (398 men and 421 women; mean +/- SD age, 74.8 +/- 11.3 years) suffered from a first-ever stroke. Eighty-nine percent of the patients had neuroimaging studies of the brain and were reclassified with the recent Application of the International Classification of Diseases to Neurology (ICD-10 NA). The occurrence of subarachnoid hemorrhage, intracerebral hemorrhage, cerebral infarction, and ill-defined events was 2.9%, 14.9%, 80.2%, and 2.0%, respectively. Crude annual incidence of first-ever stroke was 2.75/1000 (95% confidence interval [CI], 2.57 to 2.94) and 24.23/1000 (95% CI, 21.65 to 27.10) in patients older than 80 years. Incidence rates were higher in men and steeply increased with age. The standardized rate was 2.37/1000 for the Italian and 2.28/1000 for the European population. The 30-day case-fatality rate was 25.6% (95% CI, 22.8% to 28.7%). The occurrence of death, disability, and full recovery at 1 year was 36.9%, 38.9%, and 24.2%, respectively. No differences were found in stroke incidence and case-fatality according to income and urban or rural residences. CONCLUSIONS: In our population-based study, we found a high stroke incidence notably in the older age subgroups, suggesting that rather than declining, stroke is only being postponed until later in life.

Adult↗
PubMed1996

History of migraine and risk of cerebral ischaemia in young adults. The Italian National Research Council Study Group on Stroke in the Young.

BACKGROUND: A history of migraine has been proposed as a risk factor for cerebral ischaemia in women under 45. METHODS: To investigate the association between history of migraine and cerebral ischaemia, we performed a case-control study of 308 patients aged 15-44, with either transient ischaemic attack (TIA) or stroke, and of 591 age- and sex-matched controls prospectively recruited in seven university hospitals. Crude and adjusted odds ratios were calculated using logistic regression analysis. FINDINGS: A history of migraine was more frequent in patients than in controls (14.9% vs 9.1%; adjusted odds ratio 1.9, 95% confidence interval 1.1-3.1). In the prospectively designed subgroup analyses, a history of migraine reached the highest odds ratio (3.7, 95% CI 1.5-9) and was the only significant risk factor in women below age 35 (p=0.003); atherogenic risk factors were more relevant in men and in patients older than 35; previous migraine attacks with aura were more frequent in stroke patients (odds ratio 8.6, 95% CI 1-75). INTERPRETATION: Our findings indicated that the rare association between migraine and cerebral ischaemia is limited to women below age 35, and suggest a need for careful clinical evaluation of comorbidity in the presence of migraine with aura.

Adolescent↗
PubMed1995

Prevalence and outcome of symptomatic carotid lesions in young adults. National Research Council Study Group.

OBJECTIVE: To estimate the prevalence and outcome of symptomatic internal carotid artery lesions in young adults. DESIGN: Multicentre hospital based observational study with five year follow up. SETTING: Seven neurological departments in northern and central Italy. SUBJECTS: 240 patients (115 men) aged 15-44 with a recent transient ischaemic attack or stroke in the carotid territory. MAIN OUTCOME MEASURES: (a) Prevalence of symptomatic internal carotid artery stenosis or occlusion detected by continuous wave Doppler ultrasonography at entry; (b) incidence rates of cerebral, cardiac, and non-vascular death; non-fatal stroke; and non-fatal myocardial infarction. RESULTS: Carotid stenoses of 50-99% and occlusions were found in 38 patients (15.8%). Both conditions were significantly more frequent in patients aged over 35 and in those with hypertension, diabetes mellitus, and stroke at entry. The standardised mortality ratio at five years was 10.5 (95% confidence interval 5.0 to 19.3). Survival of patients with stenoses of 0-49% and occlusions was significantly better than that of patients with stenoses of 50-99%. Carotid stenosis of 50-99% was an independent predictor of death (hazard ratio 7.9; 95% confidence interval 2.2 to 29) and non-fatal stroke (hazard ratio 7.4; 1.5 to 37.4). CONCLUSIONS: The prevalence of carotid stenosis or occlusion in young adults after a cerebrovascular event is low. Though patients with high grade symptomatic carotid stenosis are at risk of non-fetal and fetal events, patients with internal artery occlusion apparently have a benign prognosis.

Adolescent↗
PubMed1995

Influence of a selective 5HT1-receptor agonist GR43175 on platelet responsiveness.

The possible interaction of sumatriptan, a selective 5HT1-receptor agonist, with platelet responsiveness has been investigated. Stimulation of platelet rich plasma with sumatriptan (1-100 microM) did not induce shape change, aggregation or modification of intraplatelet cytosolic calcium levels. Total inhibition of aggregation induced by 20 microM 5HT was observed in platelets preincubated for 20 min with 100 microM sumatriptan. In the same model, platelet stimulation with 4 microM adenosine 5'-diphosphate (ADP), concentration known to induce an irreversible single-phase curve, determined a decrease of aggregatory response. Concentrations from 1 microM to 50 microM of sumatriptan did not influence the aggregatory response induced by 5HT and ADP. These effects appear not to be determined by modifications of platelet calcium homeostasis. The possibility to modulate platelet responsiveness by sumatriptan offers a further approach for evaluating the probable link between platelet behaviour and pathophysiology of migraine.

Adenosine Diphosphate↗
PubMed1995

Manganism.

Explore the source record for details and available documents.

Humans↗
PubMed1994

Early treatment of stroke with monosialoganglioside GM-1. Efficacy and safety results of the Early Stroke Trial.

BACKGROUND AND PURPOSE: The Early Stroke Trial (EST) is a randomized, double-blind, placebo-controlled trial to assess the effect of monosialoganglioside GM-1 in improving recovery in patients who experienced an ischemic supratentorial stroke. METHODS: Sixteen clinical centers recruited 805 patients, of whom 792 were confirmed to be eligible. Treatment, consisting of a first dose of either 200 mg GM-1 or placebo, was initiated within 5 hours of the onset of stroke; a second dose of either 100 mg GM-1 or placebo was administered 12 hours later. Thereafter, patients received a daily injection of 100 mg GM-1 or placebo intravenously from day 2 through 10 and intramuscularly from day 11 through 21. Patients were followed up for a total of 4 months. RESULTS: Survival was similar in the two treatment groups. Improvement in neurological status, as measured by the change in Canadian Neurological Scale score between baseline and 4-month assessments, was greater in the group receiving GM-1; the observed difference between treatment groups was 0.22 (P = .06). A post hoc analysis in the subgroup of patients treated within 4 hours showed a statistically significant difference, with Canadian Neurological Scale mean improvement of 0.41 (P = .016). GM-1 use was not associated with differences in frequency, nature, or severity of adverse experiences. CONCLUSIONS: These findings suggest that GM-1 is safe in the dose and treatment schedule used and that its efficacy in ischemic stroke is greater when given soon after onset of stroke.

Adult↗
PubMed1993

Focal cerebral ischemia in young adults: a collaborative case-control study. The National Research Council Study Group.

Because there is uncertainty about the role of atherogenic and nonatherogenic risk factors for cerebral ischemia in the young, we carried out a multicenter, hospital-based, case-control study. 333 patients (15-44 years) with focal cerebral ischemia (transient ischemic attack or stroke within 8 weeks of admission) were eligible. 25 patients were excluded, according to the protocol. 308 cases were matched by age and gender to one hospital and one population control. Independent risk was shown by logistic conditional regression for migraine with aura [odds ratio (OR) = 14.8], smoking (OR = 3.7), alcohol (OR = 2.8), serum triglycerides (OR = 1.6), arrhythmias (OR = 9.5), mitral stenosis (OR = 56), coronary heart disease (OR = 4.3) and carotid stenosis or occlusion (OR = 41). Serum HDL-cholesterol had a relative protective effect (OR = 0.8). These data confirm the role of atherosclerosis and cardiac diseases as well as migraine with aura and alcohol consumption in the pathophysiology of cerebral ischemia in the young. More thorough prevention programs may contribute to earlier detection and control of all of these risk factors, but further investigations in patients with as yet unidentified risk factors are warranted because the above-mentioned factors do not account for the total risk of ischemic stroke in the young.

Adolescent↗
PubMed1993

A prospective study of cerebral ischemia in the young. Analysis of pathogenic determinants. The National Research Council Study Group.

BACKGROUND AND PURPOSE: The etiology of stroke in the young is different from that in older patients and remains unknown in almost one third of the cases. To gain further insight into both pathogenic and etiologic determinants, we prospectively studied a large number of consecutive young adults with focal cerebral ischemia. METHODS: Three hundred thirty-three patients aged 15-44 years with transient ischemic attack or ischemic stroke within the 8 weeks before hospital admission were recruited and investigated by using a standardized protocol of clinical evaluation, blood tests, electrocardiography, echocardiography, chest roentgenography, and brain computed tomography. Presumed etiology was diagnosed by prospectively applied criteria. RESULTS: Women predominated (61%) among patients under 35 years of age, mainly due to the frequency of cerebral ischemia related to oral contraceptive use, while men outnumbered women (60%) among patients over that age because of a higher prevalence of atherothrombotic disease. Potential cerebral embolism of cardiac origin was the presumed cause of stroke in 23.7%, but conventional sources of emboli were found only in 7.5% of cases. There was a low prevalence of atrial fibrillation among young patients with cerebral ischemia. Mitral valve prolapse was found in 8.4%, as expected, predominantly (71.4%) among the younger patients. The prevalence of stroke over transient ischemic attack was proportional to the likelihood of cardiac embolism. Acute alcohol intoxication was considered a precipitating factor in only three patients. The percentages of cerebral ischemia attributed to arterial dissection (0.3%), oral contraceptive use in women (8.1%), migraine (1.2%), and other associated medical diseases (1.5%) were lower than reported in recent clinical series. CONCLUSIONS: Two different groups of pathogenic determinants predominate in younger women and in older men, supporting public health measures aimed at strict medical control of the recognized cerebrovascular risk factors.

Adolescent↗
PubMed1992

Design and baseline results of the monosialoganglioside early stroke trial. The EST Study Group.

BACKGROUND AND PURPOSE: The Early Stroke Trial is a randomized, placebo-controlled, double-masked, multicenter study to assess the safety and efficacy of monosialoganglioside in patients who have suffered an ischemic stroke of the cerebral hemispheres. METHODS: Only patients who could be evaluated and treated within 5 hours after the onset of stroke were considered; within each center, subjects were stratified by age, sex, and clinical severity. Patients were randomly allocated to receive a specified sequence of intravenous and intramuscular doses of either monosialoganglioside or identical-appearing placebo for 21 days. Patients were followed up for 4 months after randomization. Neurological status was measured primarily by using the Canadian Neurological Scale. After assessing the effect of treatment on survival, the principal measure of efficacy will be the change in neurological status between baseline and the 4-month follow-up among survivors. RESULTS: Sixteen clinical centers, 15 in Europe and one in North America, entered a total of 792 eligible patients during a 36-month recruitment period (from May 1987 to April 1990). In our series there were more men than women, and the relative frequency of patients increased with advancing age. The most frequently associated cardiovascular conditions were hypertension, atrial fibrillation, and peripheral vascular disease. Approximately 46% of the patients were admitted to a hospital within 1 hour and 81%, within 2 hours after the onset of stroke. About 22% first received the study treatment within 3 hours and 57%, within 4 hours. CONCLUSIONS: This study demonstrates the feasibility of large-scale trials with the onset of treatment within 5 hours after an ischemic stroke.

Adult↗