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Biomedical subjects

M Rasura

Publications and source records attributed to M Rasura.

At least 19 recordsLinked to original sources
PubMed2000

Patent foramen ovale and its embolic implications.

This study investigates the usefulness of the echocardiographic characteristics of patent foramen ovale (PFO) in the stratification of stroke recurrence risk in patients with acute ischemic cerebral disease. Shunting at rest and a highly mobile fossa ovalis membrane are more frequently detected in stroke patients with PFO as the only identifiable cause of embolism. For PFO patients with both rest patency and membrane mobility > 6.5 mm, the risk of stroke/transient ischemic attack recurrence was 7.6% (95% CI, 0-18.0) at 12 months and 12.5% (95% CI, 0-26.1) at 24 months (p = 0.05). The association of both rest patency and high membrane mobility seems to identify those stroke patients with PFO at higher risk for further brain embolism.

Case-Control Studies↗
PubMed2000

Effects of intra-VTA injection of neurotensin on local cerebral glucose utilization in freely moving rats.

The [14C]2-deoxyglucose method was applied to measure the effects of the injection of neurotensin (7 microg) in the ventral tegmental area on local cerebral glucose utilization in the rat. Injection of neurotensin produced significant increases of glucose utilization in the shell of the nucleus accumbens and in the olfactory tubercle. These results indicate that stimulation of neurotensin receptors in the ventral tegmental area produces functional changes that are confined to the regions receiving mesolimbic projections within the rostral extended amygdaloid complex. These findings extend our understanding on the effects of neurotensin in the limbic system, with particular regard to reward pathways.

Amygdala↗
PubMed2000

Morphological and functional characteristics of patent foramen ovale and their embolic implications.

BACKGROUND AND PURPOSE: Transesophageal echocardiography (TEE) has detected a high prevalence of patent foramen ovale (PFO) in stroke patients, but the clinical implications of the distinctive characteristics of this patency are still a matter of debate. METHODS: We studied 350 patients with acute ischemic stroke or transient ischemic attack (TIA) within 1 week of admission. Of these, 101 (29%) were identified by contrast TEE to have a PFO; 86 patients (25%) were cryptogenic stroke patients, and 163 were excluded because of the presence of a definite or possible arterial or clinical evidence of a source of emboli or small-vessel disease. Thirteen PFO subjects without a history of embolism were designated as the control group. All PFO and cryptogenic stroke patients were followed up by neurological visits. RESULTS: Compared with controls, PFO patients with acute stroke or TIA more frequently presented with a right-to-left shunt at rest and a higher membrane mobility (P:<0. 05). Patients with these characteristics were considered to be at high risk. During a median follow-up period of 31 months (range, 4 to 58 months), 8 PFO and 18 cryptogenic stroke patients experienced recurrent cerebrovascular events. The cumulative estimate of risk of cerebrovascular event recurrence at 3 years was 4.3% (95% confidence interval [CI], 0% to 10.2%) for "low-risk" PFO patients, 12.5% (95% CI, 0% to 26.1%) for "high-risk" PFO patients, and 16.3% (95% CI, 7. 2% to 25.4%) for cryptogenic stroke patients (high-risk PFO versus low-risk PFO, P:=0.05). CONCLUSIONS: The association of right-to-left shunting at rest and high membrane mobility, as detected by contrast TEE, seems to identify PFO patients with cerebrovascular ischemic events who are at higher risk for recurrent brain embolism.

Aorta↗
PubMed1998

Central nervous system vasculitis.

Vasculitis is inflammation of blood vessel walls, which produces dysfunction in both the peripheral and central nervous system (CNS). Cerebral ischemia is the major cause for neurological manifestations of CNS vasculitis. Unfortunately, a universally accepted classification of vasculitis has not emerged. Vasculitis affecting the CNS alone is referred to as primary angiitis of the CNS; secondary vasculitis occurs in association with a variety of conditions, including infections, drug abuse, lymphoproliferative disease and connective tissue diseases. The pathogenesis of vasculitis includes different immunological mechanisms. Recently, anti-neutrophil cytoplasmatic antibody (ANCA) has been demonstrated to play an active role in the immunopathogenesis of the vasculitis. Diagnosis of vasculitis depends on a combination of clinical, radiographic and pathologic features. A wide spectrum of clinical features may occur. The most typical clinical picture of CNS vasculitis is troke, encephalopathy or seizures. Assays for ANCA, serum cytokines, antibodies to endothelial cell antigens have been reported to be useful in diagnosing or monitoring the disease activity. The gold standard in diagnosis is confirmation of vasculitis in a biopsy specimen. Angiography may suggest the diagnosis but no abnormalities are pathognomonic. Ideally, the therapy of each vasculitis would focus on the specific immunologic mechanism causing the disease. Such specific interventions are not yet available. In general the most important approaches induce global immunosuppression. The goal of therapy, however, is to prevent recurrence of disease.

Central Nervous System Diseases↗
PubMed1998

Long-term prognosis after a minor stroke: 10-year mortality and major stroke recurrence rates in a hospital-based cohort.

BACKGROUND AND PURPOSE: Determinants of long-term outcome are not well defined in minor stroke patients. This study aims to evaluate which factors are independent long-term predictors of death and major stroke recurrence in a cohort of minor ischemic strokes. METHODS: A cohort of 322 patients with first-ever minor ischemic strokes (mean age, 55 years; 89% were treated with antiplatelet or anticoagulant drugs) with minor (Rankin score=2) or no disability (Rankin score <2) were followed for 10 years, with only 6% lost to follow-up. Death and major stroke recurrence rates were evaluated by Kaplan-Meier analysis. Hazard ratios and 95% confidence intervals (CI) of factors with P<.1 at the log-rank test were evaluated by multivariate Cox analysis. RESULTS: The 10-year mortality rate was 32%, with a relative risk of 1.7 (95% CI, 1.4 to 2.1) compared with the age- and sex-matched general population. The 10-year recurrence rate of major strokes was 14%. The hazard ratio (95% CI) of death was 1.1 (1.05 to 1.09) for age (1-year increments), 3.4 (2.2 to 5.2) for minor disability, 1.8 (1.1 to 3.1) for myocardial infarction (MI), 2.0 (1.1 to 3.7) for nonvalvular atrial fibrillation, and 1.8 (1.2 to 2.7) for hypercholesterolemia. The hazard ratio (95% CI) of major stroke recurrence was 2.8 (1.3 to 6.2) for recurrent minor strokes, 3.1 (1.9 to 4.6) for nonlacunar stroke, 2.9 (1.3 to 6.8) for MI, and 3.0 (1.4 to 6.4) for hypertension. CONCLUSIONS: In minor ischemic strokes, age, minor disability, MI, nonvalvular atrial fibrillation, and hypercholesterolemia increase the risk of death; recurrent minor strokes, nonlacunar stroke, MI, and hypertension increase the risk of major stroke.

Age Factors↗
PubMed1996

Microembolization from a carotid mural thrombus detected by transcranial Doppler.

Over the last few years, many authors have described the possibility of using transcranial Doppler to demonstrate the passage of microemboli in the cerebral arteries. We report the case of a 44-year-old woman with thrombotic diathesis and thrombocytosis who was admitted twice within a short period of time (one and a half months) to a neurological department because of multiple cerebral infarctions. On the occasion of the second admission, a colour-Doppler examination of the epiaortic vessels, which had previously been negative, showed a carotid lesion due to a mural thrombus and, on the same side as the carotid lesion, transcranial Doppler detected short-duration, high-intensity signals in the middle and anterior cerebral arteries, an expression of the passage of microemboli. As already described by other authors in similar clinical situations, our case confirms that transcranial Doppler can identify the passage of microemboli in the circle of Willis.

Adult↗
PubMed1994

Paramedian diencephalic syndrome.

The clinical characteristics of paramedian diencephalic syndrome (PDS) are described on the basis of two recently observed cases: one with paramedian thalamic infarct, the other with paramedian thalamopeduncular infarct. Analysis of the clinical symptoms and the results of CBF study show that PDS is a complex neurological syndrome characterized by symptoms due to both anatomical lesions and functional disconnections.

Aged↗
PubMed1994

Antiphospholipid antibodies and cerebral artery dissection: two frequent causes of brain ischemia in young adults.

As part of a multicenter study on ischemic stroke in the young, we report the occurrence of high antiphospholipid antibody (aPLs) levels and cerebral dissection in 75 patients. These represent the two most frequent non-thromboembolic causes of cerebral ischemia in our population. Increased aPL titres were found in nine cases (12%); cerebral artery dissection in eleven (14%). Our data stress the need to modify the classical diagnostic approach to cerebral ischemia by including hematological assessments and new neuroimaging techniques as screening tests.

Adult↗
PubMed1994

[Transesophageal echocardiography in patients with ischemic stroke with and without clinical evidence of heart disease].

Transesophageal echocardiography (TEE) is useful in the assessment of potential cardiac sources of emboli in patients with ischemic stroke and clinical history of heart disease. Aim of our study was to assess the utility of TEE in stroke patients with and without clinical evidence of cardiac disease. In addition, we evaluated if multiplane TEE, versus mono and biplane TEE, provides additional information about potential cardiac sources of emboli. A total of 89 ischemic stroke patients were studied: 30 patients with a history and clinical evidence of cardiac disease (Group A) and 59 patients without evidence of cardiac disease (Group B). All patients had a documented ischemic lesion of the brain. Patients who had an extracardiac potential source of emboli were excluded from the study. In all patients, transthoracic (TTE) and biplane TEE were performed, whereas omniplane TEE was performed in 40 patients only. In Group A, sources of emboli were disclosed by TTE in 33% of the patients. When TEE was performed the percentage of positive cases raised to 83% (p < 0.001). In Group B, TTE was positive in only 10% of the patients as opposed to 43% with TEE (p < 0.001). Omniplane TEE revealed a potential source of emboli in 23 out of 40 (57%) patients versus 16/40 (40%) and 20/40 (50%) with monoplane and biplane, respectively. TEE is useful in patients with cardiovascular disease in whom clinical evaluation and TTE are negative for sources of emboli. TEE is of great value in stroke patients without clinical evidence of cardiovascular disease in whom an extracardiac potential source of emboli has been excluded.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Lupus anticoagulant and the fibrinolytic system in young patients with stroke.

BACKGROUND AND PURPOSE: Our purpose was to assess the presence of lupus anticoagulant and fibrinolytic system abnormalities in young patients with stroke. METHODS: We studied 33 consecutive ischemic patients aged < 50 years. Lupus anticoagulant was screened by four different coagulation tests, and the fibrinolytic system was studied by analyzing tissue plasminogen activator antigen and plasminogen activator inhibitor activity. RESULTS: Six patients (18%), two of whom were affected by systemic lupus erythematosus, had lupus anticoagulant. Plasminogen activator inhibitor activity was significantly higher in those positive for lupus anticoagulant than in those negative for lupus anticoagulant and control subjects (p < 0.001). CONCLUSIONS: In young patients with stroke, lupus anticoagulant is associated with an imbalance of the fibrinolytic system as a result of higher levels of plasminogen activator inhibitor.

Adult↗
PubMed1993

Blood brain barrier breaking. Is still an absolute contraindication to early surgical reperfusion of the brain?

In the early treatment of the patients with cerebrovascular insufficiency due to internal carotid artery stenosis, the presence of a cerebral infarct and especially the blood brain barrier breaking (BBB) are considered by many as a contraindication to early reperfusion by carotid endarterectomy (CEA). Generally, it has been recommended to differ the operation at least for 4-6 weeks because of the high risk to convert an ischemic infarct into an hemorrhagic one. On the other hand, because unfavorable natural history has been reported as for the progressing unstable neurological deficit as for the minor recent strokes, respectively by Millikan and Dosik, it seem to be justified a more aggressive management with the aim of: 1) eliminating the stenosis as embolic source of emboli; 2) obtaining early brain reperfusion to increase the probability of good recovery. Some previous experiences reported in the literature demonstrated satisfactory results of early reperfusion even in presence of BBB. The Authors present 4 cases of early CEA in patients with BBB. After the CT scan the patients have been submitted preoperatively to non invasive tests (duplex scanning and transcranial Doppler sonography) to assess the presence of the internal carotid artery stenosis and the viability of the intracranial cerebral arteries with special regard to the middle cerebral artery. All the patients underwent CEA in loco-regional anesthesia and particularly systemic blood pressure was carefully monitored and any hypertensive status was early corrected by prompt antihypertensive therapy (i.v. nitrates and or calcium blocking agents).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Circadian variation in the frequency of ischemic stroke.

The frequency of myocardial infarction and sudden death is increased between 6 AM and noon. To determine whether the same is true for the onset of ischemic stroke, we studied 426 consecutive patients within 12 hours after the onset of their first hemispheric stroke. The frequency of onset of hemispheric stroke was significantly (p = 0.0001) higher from 6:01 AM to noon (56.1%) than from 12:01 PM to 6 PM (20.2%), from 6:01 PM to midnight (8.2%), and from 12:01 AM to 6 AM (15.5%). The identification of periods of high risk for vascular events may have important therapeutic implications, such as matching drug effects with vulnerability.

Aged↗
PubMed1989

Influence of nimodipine on cerebral blood flow in human cerebral ischaemia.

Cerebral blood flow (CBF) was measured by xenon-133 inhalation and single photon emission computerized tomography (SPECT) in 7 patients with acute cerebral ischaemia prior to and 30 min after intravenous infusion of nimodipine (1 mg). Neurological examination, CT and CBF study were performed no later than 6 h after the onset of symptoms. Regional perfusion abnormalities were seen in all patients when the CT scan was still normal. Follow-up CT revealed low-density areas roughly corresponding to the core of the perfusion defect. Nimodipine infusion significantly decreased the mean arterial blood pressure (P less than 0.01), while PaCO2 and clinical symptoms remained unchanged. A significant CBF improvement (P less than 0.05) after nimodipine was seen in the border zone of the ischaemic infarct but not in the core of the lesion or in the unaffected contralateral hemisphere.

Adult↗