Biomedical subjects

N M Bornstein

Publications and source records attributed to N M Bornstein.

At least 19 recordsLinked to original sources

PubMed2006

Hemodynamic effects of liquid food ingestion in mid-thoracic paraplegia: is supine postprandial hypotension related to thoracic spinal cord damage?

BACKGROUND: Postprandial hypotension (PPH) appears in various conditions with autonomic failure and was symptomatic in a patient with thoracic paraplegia, but was not remarkable in patients with tetraplegia. OBJECTIVE: To determine whether the pathology causing PPH may include a thoracic but not a cervical spinal cord lesion (SCL). DESIGN: An experimental controlled study. SETTING: The spinal research laboratory, Loewenstein Hospital, Raanana, Israel. SUBJECTS: Thirteen healthy subjects, 10 patients with traumatic T(4)-T(6) paraplegia, and 11 patients with traumatic C(4)-C(7) tetraplegia. MAIN OUTCOME MEASURES: Heart rate (HR), blood pressure (BP), HR and BP spectral components (LF, HF, LF/HF), cerebral blood flow velocity (CBFV), and cerebrovascular resistance index (CVRi). METHODS: The effects of a standard liquid meal on the outcome measures were compared between the three subject groups monitored for HR, BP, and CBFV, from 55 min before to 45 min after the start of the meal. The recorded signals were digitized online and analyzed off-line in the time and frequency domains. RESULTS: After meal, BP decreased only in the paraplegia group (P<0.01), HR increased more prominently in this group (P<0.01), CVRi tended to decrease only in the paraplegia group, CBFV did not change significantly in any group, and HR LF/HF increased (P<0.001) in all groups but tended to increase more in paraplegia. CONCLUSIONS: Patients with mid-thoracic SCL may develop PPH. The pathology causing PPH can include a thoracic but not a cervical SCL. The normal hemodynamic reaction to liquid meal ingestion is mediated through the mid-thoracic spinal cord. The sympathovagal balance increases after food ingestion, more prominently in patients with PPH, and cerebrovascular resistance changes during PPH may help maintain the cerebral circulation.

Adolescent↗

PubMed2006

Cerebral vasomotor reactivity of bilateral severe carotid stenosis: is stroke unavoidable?

We evaluated the cerebral hemodynamic features of severe bilateral carotid stenosis by assessing and comparing cerebral vasomotor reactivity (VMR) in the middle cerebral (MCA) and vertebral arteries (VA) by transcranial Doppler and the Diamox (1 g acetazolamide i.v.) test. VMR was evaluated by recording the percentage differences in peak systolic blood flow velocity in each MCA and VA at baseline and by the Diamox test. Twenty-eight symptomatic (SCAS) and 31 asymptomatic (ACAS) patients with bilateral severe (>70%) internal carotid artery stenosis were studied. The mean MCA VMR% was 29 +/- 26.9% in SCAS and 43.2 +/- 26.8% in ACAS patients (P < 0.01). Their respective mean VA VMR% was 30.2 +/- 36.5% and 39.6 +/- 24.4% (P = NS). VMR% of the symptomatic MCA side in SCAS patients was significantly lower than the opposite side (20.5 +/- 31.1% and 39.2 +/- 37.9% respectively; P < 0.03). In contrast, the VA VMR% of both sides in SCAS patients remained similar (28.1 +/- 39.3% and 34.6 +/- 47.9% respectively; P = NS). VMR% of the MCA and VA in ACAS patients was also similar for both sides of bilateral carotid stenosis. The cerebral hemodynamic features differ between SCAS and ACAS patients with bilateral carotid occlusive disease in the anterior part of the circle of Willis. An independent cerebral vascular reserve capacity of the posterior circulation is proposed.

Aged↗

PubMed2006

Wide-range C-reactive protein efficacy in acute ischemic stroke patients.

OBJECTIVE: To compare the recently introduced wide-range C-reactive protein (wr-CRP) with the widely used high-sensitivity Behring Dade method (hs-CRP) in acute stroke/transient ischemic attack (TIA) patients. MATERIALS AND METHODS: A total of 119 consecutive patients admitted to a tertiary medical center with acute ischemic stroke/TIA were included in the study. Venous blood was obtained for both assays during the first 24 h, 3-5 days, as well as 3-6 months thereafter. RESULTS: A highly significant correlation (r=0.994, P<0.0001) was found between the two methods even when analyzed at three different time points. In addition, a similar correlation was noted between these two assays and other commonly used biomarkers, including white blood cell count, Westergren's sedimentation rate and quantitative fibrinogen. CONCLUSION: Real-time, on-line and low-cost wr-CRP assay is a reasonable alternative to the Behring Dade hs-CRP method in acute stroke/TIA patients.

Acute Disease↗

PubMed2004

Triggering risk factors for ischemic stroke: a case-crossover study.

BACKGROUND: While vascular risk factors for stroke are well established, little is known about factors that may precipitate the acute event. In this study the authors investigated the association between exposure to seven potential triggers during waking hours and acute onset of ischemic stroke. METHODS: In a case-crossover study, 200 consecutive stroke patients were interviewed 1 to 4 days after the event using a validated questionnaire. Reported exposure to potential triggers including negative and positive emotions, anger, sudden posture changes as response to a startling event, heavy physical exertion, heavy eating, and sudden temperature changes during a 2-hour hazard period prior to stroke onset were compared to the same period during the preceding day and to average exposures in the last year. RESULTS: Seventy-six patients (38%) reported exposure to at least one of the study triggers during the 2-hour hazard period. For all factors combined, the OR was 8.4 (95% CI 4.5 to 18.1). The OR for negative emotions was 14.0 (95% CI 4.4 to 89.7), for anger 14.0 (95% CI 2.8 to 253.6), and for sudden changes in body posture in response to a startling event 24.0 (95% CI 5.1 to 428.9). It is important to interpret the reported ORs as estimates of a short-term 2-hour period relative risk and not as cumulative risks. CONCLUSIONS: Negative emotions, anger, and sudden changes in body posture in response to a startling event appear to be independent triggers for ischemic stroke.

Adrenergic beta-Antagonists↗

PubMed2004

Early CT changes and outcome of ischemic stroke.

Although recombinant tissue plasminogen activator (rt-PA) was rapidly implemented as part of the emergency care of acute stroke, its use in daily clinical practice still remains controversial in many countries. The most important question is criteria for careful selection of subgroup of patients for this treatment. It has been hypothesized that early computed tomography (CT) changes of ischemia are risk factors for symptomatic intracerebral hemorrhage and poor outcome. We conducted a prospective outcome study of patients with acute ischemic stroke (IS) admitted to the hospital within 6 h of symptom onset. Experienced neuroradiologists blind to the clinical outcome of the patients read all CT scans carried out in the emergency room. Early CT changes were defined as in European Cooperative Acute Stroke Study (ECASS) 2. There were 150 patients (75 males, mean age 72.5 +/- 9.0) with acute IS (54.7% with mild stroke and 45.3% with severe stroke). Early CT changes were presented with tissue hypodensity - 55.7%, effacement of sulci - 41.3%, hyperdensity of middle cerebral artery (MCA) - 13.3%, hypodensity of lentiform - 20.7%, loss of insular ribbon sign - 28.7%. Follow-up after 30 days showed that 44% of the patients were discharged home, 20% were discharged to rehabilitation facilities, 22% were discharged to chronic care institutions and 14% died. Data were statistically analyzed. Our data suggest that early signs on CT scan could not predict outcome of patients with acute IS.

Aged↗

PubMed2003

Cerebral vasomotor reactivity of the posterior circulation in patients with carotid occlusive disease.

We evaluated the hemodynamic features of the posterior circulation in patients with severe carotid stenosis by assessing and comparing cerebral vasomotor reactivity (VMR) in the middle cerebral (MCA) and vertebral arteries (VA) by transcranial Doppler and the Diamox (1 g acetazolamide i.v.) test. Sixty symptomatic and 111 asymptomatic patients with unilateral severe (>70%) internal carotid artery stenosis were studied. The VMR was 19.2 +/- 18.9% for the MCA ipsilateral to the stenosis and 27.3 +/- 17.4% on the contralateral side (P < 0.0001) for all patients. It was 18.2 +/- 23.2% for the VA ipsilateral to the stenosis and 19.7 +/- 21% on the contralateral side (P = NS). The symptomatic patients' VMR of the MCA on the side of stenosis and the opposite side were 19.2 +/- 17.6 and 29 +/- 17.2%, respectively (P < 0.03). The VMR of the VA remained similar (15.1 +/- 21 and 21.6 +/- 6%, respectively, P = NS). The asymptomatic patients' VMR of the MCA on the side of the stenosis was also lower (19.2 +/- 19.7 vs. 26.5 +/- 17.5% on the opposite side, P < 0.001). In contrast, the VMR in the VA was similar (19.8 +/- 21.4 and 18.7 +/- 19.5%, respectively, P < 0.6, NS). Thus, the VMR of the posterior circulation remained similar regardless of carotid stenosis and a symptomatic/asymptomatic course of carotid occlusive disease, suggesting an independent cerebral vascular reserve capacity of the posterior circulation.

Aged↗

PubMed2002

Prognostic implications of admission inflammatory profile in acute ischemic neurological events.

OBJECTIVE: To reveal the potential prognostic implications of admission inflammatory markers in patients with acute ischemic neurological events. PATIENTS AND METHODS: Sixty patients with an acute ischemic neurological event who were examined within 24 h from the appearance of symptomatology. We determined the high-sensitive C-reactive protein (hs-CRP) concentrations, erythrocyte sedimentation rate (ESR), fibrinogen concentrations and degree of erythrocyte adhesiveness/aggregation. RESULTS: A significant correlation was noted between baseline hs-CRP concentrations, ESR as well as adhesiveness/aggregation and the outcome of the ischemic neurological event as determined by the modified Rankin scale 8-12 months following the insult. CONCLUSION: Admission inflammatory markers have long-term prognostic implications in patients with acute ischemic neurological events. These findings are relevant in view of the new therapeutic interventions now available for reducing the inflammatory response.

Acute Disease↗

PubMed2002

Stroke in hospitalized patients: are there special risk factors?

BACKGROUND AND PURPOSE: The occurrence of stroke in patients hospitalized for various illnesses remains a particular challenge for neurologists. Determining the potential causes for these particular cerebrovascular events may help to define the population at risk and to take measures in order to prevent stroke during hospitalization. The aim of our study was to evaluate the potential risk factors associated with stroke, which occurred in patients hospitalized for other illnesses. METHODS: This retrospective case-control study based on data of patients who underwent an ischemic stroke while being hospitalized not because of stroke and a control group of patients admitted during the same period who were matched for age and sex to the study patients. Common vascular risk factors, e.g. fever, leukocytosis, blood pressure, hemoglobin, cardiac arrhythmia and dehydration, were compared between the study and control groups. RESULTS: Of 2,247 consecutive patients with ischemic stroke, the stroke had occurred during hospitalization not related to any surgical procedure in 80 (3.5%). Six parameters were found as being significant independent risk factors for in-hospital stroke: fever and leukocytosis during hospitalization, elevated diastolic and unstable blood pressure, dehydration and past history of myocardial infarction. CONCLUSION: Careful monitoring of temperature, blood count, blood pressure, and clinical and laboratory signs of dehydration is needed to prevent in-hospital stroke.

Aged↗

PubMed2001

Antibodies to brain antigens following stroke.

Cerebral necrosis following stroke exposes brain antigens to the immune system, potentially initiating an antibody response. The authors measured levels of antibodies to specific neuronal antigens, neurofilaments (NF), and a ubiquitous antigen, cardiolipin (CL), in 45 patients following an acute first-ever stroke, within 48 hours, and 1, 3, and 6 months later. The mean levels of anti-NF antibodies were elevated compared with baseline at 1, 3, and 6, months (p = 0.012, 0.002, and 0.003 by paired t-test). Anti-CL levels did not change significantly.

Acute Disease↗

PubMed2001

The state of leukocyte adhesiveness/aggregation in the peripheral blood of patients with type 2 diabetes and ischemic vascular disease.

White blood cells have a potential role in the pathogenesis of vasculopathy in diabetic patients. We studied the circulating peripheral blood in a cohort of patients with documented ischemic heart or brain disease with and without type 2 diabetes by means of image analysis and flow cytometry. Our study showed that the state of leukocyte adhesiveness/aggregation is slightly increased in those who had concomitant diabetes but that there was no difference regarding the expression of CD11b/CD18 and CD62L antigens on the surface of the peripheral blood white blood cells. The finding of a significantly increased number of white blood cells in the peripheral blood of patients with ischemic vascular diseases is important insofar as it is associated with a poorer prognosis.

Aged↗

PubMed2001

The erythrocyte adhesiveness/aggregation test in the peripheral blood of patients with ischemic brain events.

We adopted a simple slide test and image analysis to determine the state of erythrocyte adhesiveness/aggregation in the peripheral blood of 45 patients with acute ischemic stroke, 30 with TIA and 27 matched controls. A highly significant (P=0.005) difference was noted between patients and controls regarding the degree of erythrocyte adhesiveness/aggregation while there was no significant difference for both erythrocyte sedimentation rate or fibrinogen concentrations. We suggest that our slide test might be a low cost and real time method to detect the increased erythrocyte aggregability in the peripheral blood of patients with acute ischemic neurological events. These findings might be relevant in view of recent studies that suggest a favorable effect of therapeutic interventions directed at the improvements of this hemorrheological aspect in individuals with ischemic vascular conditions.

Aged↗

PubMed2001

Antiplatelet drugs: how to select them and possibilities of combined treatment.

Antiplatelets are the pivotal drugs in preventing recurrent stroke or other major vascular events in patients who have undergone TIA or stroke. Aspirin is the most widely used, although its effect is very modest (relative risk reduction 20%), and most physicians use between 100 and 325 mg daily as a maintenance dose. For patients who develop stroke on aspirin treatment, the options are either to increase the dose of aspirin or to administer another anti-aggregate. No study has yet been performed to support these approaches. In patients who cannot tolerate aspirin, the options are clopidogrel 75 mg once daily or dipyridamole 400 mg combined with 50 mg aspirin. An approach which is very appealing, but not yet proven is to combine different antiplatelet drugs with different modes of action, such as aspirin and clopidogrel, in order to achieve a better and more effective antithrombotic effect. Further controlled trials are needed to justify this approach.

Drug Therapy, Combination↗

PubMed2001

Population group differences in trends in stroke mortality in Israel.

BACKGROUND AND PURPOSE: In Israel, stroke is the third most common cause of death. In 1997 stroke accounted for 2905 deaths (8.1% of total), 1390 of them among men (7.5% of total; crude mortality rate of 48.3/100 000) and 1515 among women (8.6% of total; crude rate of 51.7/100 000). This report presents trends on stroke mortality by population group and estimates of morbidity in Israel. METHODS: Data on stroke mortality in Israel during 1969-1997 were obtained from the Israel Central Bureau of Statistics. Age-specific and age-adjusted mortality rates were calculated for the 2 main population groups. Data on morbidity were obtained form the 1996/1997 National Health Survey. Hospitalization rates due to stroke are based on the national hospitalization data. RESULTS: A monotonic decrease in stroke mortality is evident in Jews during 1969-1997 in both sexes. Age-adjusted mortality rates declined by 62.5% for Jewish men and by 73.4% for Jewish women during 1969-1997. Among Arabs, there was a general decreasing trend in the mortality for both sexes during 1973-1997. The main difference in population group mortality trends was found in the group aged >/=75 years: a statistically significant decrease in mortality rates for Jews is evident, while no decrease is apparent for Arabs. On the basis of available data for 1990, an estimated 13 000 patients with stroke were hospitalized during 1997. CONCLUSIONS: During the last 25 years, age-adjusted stroke mortality in Israel has declined substantially, but the decline has been much greater among Jews than Arabs. The group aged >/=75 years shows the greatest difference in trends between Jews and Arabs. This finding may be explained by differences in risk factor distribution and case fatality rates.

Acute Disease↗

PubMed2001

TCD and the Diamox test for testing vasomotor reactivity: clinical significance.

Transcranial Doppler sonography has become widely used in assessing cerebral vasomotor reactivity which provides information regarding cerebral autoregulation and collateral circulation. Cerebral vasomotor reactivity is defined as a shift between cerebral blood flow or cerebral blood velocity before and after administration of a potent vasodilatory stimulus test. Three such tests are currently used for this purpose: the apnea test, CO2 inhalation and the Diamox test (i.v. acetazolamide), all of which are based on the dilatatory response of cerebral blood flow to hypercapnia. Certain advantages of the Diamox test were described, but each of the three tests has its strong and weak points, and this will be the topic under discussion. There are several practical applications of the combined TCD and the vasodilatory tests in assessing of cerebral vasomotor reactivity: 1. To evaluate the intracranial hemodynamic status in patients with carotid occlusive disease with the intent of predicting the occurrence of ischemic brain events. 2. To compare intracranial hemodynamics before and after carotid endarterectomy. 3. To compare autoregulation and collateral circulation in the different parts of the circle of Willis. 4. To predict dementia after stroke. In summary, the potential clinical usefulness of combined TCD and provocative vasodilatory tests has been clearly shown. Further large scale studies are needed in order to augment the applications of cerebral vasomotor reactivity assessment in the clinical setting.

Acetazolamide↗

PubMed2000

Stroke prevention: cardiac and carotid-related stroke.

The aim of this article is to discuss cardiac sources of stroke as well as the management of symptomatic and asymptomatic carotid stenosis. The authors detail the risks of cardioembolic stroke in the following conditions: aortic arch atheroma, atrial fibrillation, atrial myxoma, atrial septal aneurysm, dilated cardiomyopathy, infective endocarditis, left ventricular thrombus, mitral annular calcification, mitral valve prolapse, patent foramen ovale, prosthetic heart valves, valvular strands, and the optimal medical management for these conditions. The indications for carotid endarterectomy, angioplasty, and stenting are also outlined.

Carotid Stenosis↗

PubMed2000

Vasomotor reactivity in the ophthalmic artery: different from or similar to intracerebral vessels?

OBJECTIVE: In order to evaluate hemodynamic features of ophthalmic arteries in patients with severe carotid artery stenosis, we assessed and compared vasomotor reactivity in the middle cerebral and ophthalmic arteries. METHODS: Sixty-five patients (25 symptomatic, 40 asymptomatic) with severe (70-99%) internal carotid artery stenosis were studied using transcranial Doppler and the Diamox test. RESULTS: Vasomotor reactivity was found to be similar in the middle cerebral and ophthalmic arteries on the side of severe carotid stenosis in both symptomatic and asymptomatic patients. In contrast, the vasomotor reactivity of the ophthalmic arteries was significantly different from that of the middle cerebral arteries on the side of the normal or the non-significantly stenotic side of the internal carotid artery. CONCLUSIONS: These data suggest a specific autoregulative response of the ophthalmic artery compared to that of the middle cerebral artery and may shed light on the role of the ophthalmic artery in oculovascular hemodynamics.

Acetazolamide↗

PubMed2000

Are there any unique epidemiological and vascular risk factors for ischaemic strokes that occur in the morning hours?

It is now accepted that the incidence of ischaemic stroke is significantly increased in the morning. Any attempts to prevent its occurrence must be based on determining the mechanisms, special risk factors and appropriate protective measures needed during this vulnerable period. We studied the epidemiological features of morning stroke and reviewed the records of 2312 consecutive patients recorded prospectively in the Tel Aviv Stroke Register. Information about time of stroke onset was obtained from the patient, family members or other observers. The study parameters of age, sex, vascular distribution (carotid versus vertebrobasilar), ischaemic heart disease, myocardial infarction, diabetes mellitus, arterial hypertension, smoking, hyperlipidaemia, stroke severity and recurrence were compared between patients with morning stroke and those with stroke occurring at other times. In 599 patients (34%) stroke occurred between 06:00 and 10:00 h. No evaluated parameter was found to be statistically different among the morning stroke patients compared with stroke occurring at other times (P < 0.2). Patients with arterial hypertension and ischaemic heart disease and male patients had a greater likelihood of stroke occurrence between 22:00 and 02:00 h (P < 0.05). Our data suggest that none of the common vascular risk factors could explain the morning peak of stroke occurrence. The next step in the quest for understanding the phenomenon of circadian variation is to identify other physiological factors and the effects of pharmacological agents in morning stroke protection.

Brain Ischemia↗

PubMed2000

Activated polymorphonuclear leukocytes and monocytes in the peripheral blood of patients with ischemic heart and brain conditions correspond to the presence of multiple risk factors for atherothrombosis.

OBJECTIVE: Risk factors like hypertension, diabetes mellitus, dyslipidemia and smoking contribute to the pathogenesis of atherothrombosis. We investigated whether the multiplicity of risk factors for atherothrombosis is associated with leukocyte activation. METHODS: We examined the availability of CD11b/CD18 antigen on the surface of peripheral blood polymorphonuclear leukocytes and monocytes in patients with acute ischemic heart and brain conditions. RESULTS: There was a highly significant (p<0.00001) increment in the availability of the CD11b/CD18 antigen on the surface of the polymorphonuclear leukocytes in patients with multiple (2 or more) vascular risk factors [mean fluorescence intensity (MFI) +/- SD, 210+/-102] as opposed to individuals with none or 1 risk factor for atherothrombosis (MFI 159+/-73). Similar results were observed on the monocytes: 309+/-151 and 235+/-97, respectively (p<0. 00001). CONCLUSION: The multiplicity of risk factors for atherothrombosis is associated with the up-regulation of CD11b/CD18 antigen on the surface of peripheral blood polymorphonuclear leukocytes and monocytes, suggesting the presence of an increased inflammatory response and leukocyte activation in these individuals.

Acute Disease↗