Frequency Of Transient Ischemic Attacks Research Articles

CLINICAL APPLICATION STUDY OF 3D-ASL PERFUSION IMAGING AND MAGNETIC RESONANCE DIFFUSION IMAGING IN TRANSIENT ISCHEMIC ATTACK.

Objective: This study aimed to explore the clinical application of three-dimensional arterial spin labeling (3D-ASL) and diffusion-weighted magnetic resonance imaging (DWI) in transient ischemic attacks. Methods: Forty patients with transient cerebral ischemia in our hospital were selected and included from July 2020 to March 2022. All subjects were detected by DWI and 3D-ASL technology. The positive rate, relative cerebral blood flow (rCBF), and the receiver operating characteristic curve of the two methods in the diagnosis of transient cerebral ischemia were compared; the objective was to compare the relationship between the frequency of transient ischemic attack and hypoperfusion, and vascular stenosis. Results: The 3D-ASL examination showed two cases of hypoperfusion in the healthy control group (5.00), and the magnetic resonance imaging examination showed four cases of vascular stenosis in the healthy control group (10.00). The rCBF ratio in the cerebral ischemia group was significantly lower than that in the cerebral ischemia group, which was significantly lower than that in the healthy control group ( P < 0.05). The area under the curve (AUC) of 3D-ASL in the diagnosis of transient cerebral ischemia was 0.800, and the AUC of DWI in the diagnosis of transient cerebral ischemia was 0.725. The AUC of the combination of the two methods in transient cerebral ischemia was 0.850. There was a significant difference in the attack frequency of patients with transient cerebral ischemia with different perfusion ( P < 0.05). There was a significant difference in attack frequency between patients with transient ischemic attack and patients without vascular stenosis ( P < 0.05). Conclusion: 3D-ASL and DWI technology have higher diagnostic efficiency for transient cerebral ischemia.

Vascular comorbidities in patients with multiple sclerosis and their impact on physical disability.

Aim Given the impact of vascular comorbidities (VC) on the diagnosis, treatment, and outcome of multiple sclerosis (MS), we examined the incidence and correlation of VC and risk factors for vascular disease in people with MS (PwMS) compared to the general population, and the impact on the physical disability of patients. Methods Cross-sectional study involved 100 patients with MS and 50 healthy people from the general population, matched by sex and age. The values of demographic, biochemical, and anthropometric parameters, the presence of VC and risk factors for vascular diseases in both groups, and clinical parameters in PwMS were analysed. Statistical analysis included methods of descriptive statistics, χ2 test, Student's t-test, analysis of variance, correlation and regression analysis. Results Groups differed by a higher frequency of transient ischemic attack in the control group (p=0.024), and the treatment of hypertension (p=0.038) and smoking frequency (p=0.044) in the MS group. Normal triglycerides levels were statistically significantly more prevalent in the MS group (p=0.000). Total body weight and BMI were statistically significantly higher in the control group (p=0.000). The increase in Expanded Disability Status Scale (EDSS) score was associated with higher levels of total (p=0.001) and low-density lipoprotein (LDL) cholesterol (p=0.003), and activated partial thromboplastin time APTT (p=0.002). Conclusion In PwMS it is necessary to pay attention to the higher frequency of smoking than in general population, and the impact of total cholesterol, LDL and APTT levels as significant parameters that affect physical disability.

Impact of Atrial Fibrillation on the Severity, Progress, and Disability of the Ischemic Stroke Patients

Background and Aim: The association of atrial fibrillation (AF) with the ischemic stroke has emerged as an area of clinical research. The purpose of the present study is to investigate possible correlations between the severity, progress, and outcome of ischemic stroke and the presence of AF. Materials and Methods and Results: The clinical assessment of patients was based on the neurological status at the time of diagnosis utilizing the National Institutes of Health Stroke Scale (NIHSS), the neurological semiology during hospitalization (improvement, deterioration, and without differentiation), and the final outcome at the end of the treatment optimizing the modified Rankin scale (mRS). A total of 344 patients diagnosed with an ischemic stroke were enrolled in the study. The presence of AF was found to be associated with higher severity, poorer progress, and more adverse clinical outcomes of the ischemic stroke. Furthermore, a lower frequency of transient ischemic attacks was observed in patients with AF. Finally, patients with AF presented higher incidence of middle cerebral artery occlusion and were more frequently found with a lesion on the left brain hemisphere. Conclusion: AF was found to be highly associated with higher severity and poorer prognosis of ischemic strokes, independently from the presence of other cardiovascular risk factors.

Secondary prevention of cerebrovascular events in patients with “asymptomatic” atherosclerotic stenosis of the vertebral arteries and unfavorable prognostic factors of chronic cerebral ischemia

Abstract Aim To evaluate the three-year results of endovascular interventions in patients with “asymptomatic” atherosclerotic stenosis of the vertebral arteries as a method of secondary prevention of cerebrovascular events. Material and methods The patients were randomized into 2 groups: in group I (n=60), secondary prevention of cerebrovascular events were carried out in a combined strategy - stenting of the vertebral arteries in combination with medication therapy, and in group II (n=60) - only medication therapy. Long-term follow-up were planned in 12, 24 and 36 months. Inclusion criteria: patients with “asymptomatic” stenosis of the vertebral arteries 50–95%; the diameter of the vertebral arteries is not less than 3.0 and not more than 5 mm; the presence of not gross cerebral and focal symptoms corresponding to the initial (asymptomatic) stage of encephalopathy (according to E.V. Schmidt); the presence of at least one factor for an unfavorable prognosis of chronic cerebral ischemia: arrhythmia, total cholesterol level more than 6.0 mmol / l, open Willis circle, arterial hypertension, bilateral lesion of the vertebral arteries, low-density lipoprotein level more than 3.5 mmol / l, combined lesion of the vertebral and carotid arteries, calcification of the vertebral arteries, a coronary heart disease in anamnesis. Primary endpoints: the total incidence of cardiovascular events. Results In all patients from group I, stenting of the vertebral arteries was performed without the use of embolic protection devices. The total incidence of major cerebral complications by the end of the study was 5.9% in group I and 25.0% in group II (χ2=4.825; p=0.023). In group I by the end of the study, the total incidence of stroke was 2.9%, and in group II it reached 30.5%. The total frequency of transient ischemic attack was 5.8 and 8.3%, respectively (χ2=4.135; p=0.042). The incidence of cardiac complications was 8.8 and 27.8%, respectively, in groups I and II (χ2=4.154; p=0.042). The survival rate, free from major cerebral complications, as well as cardiac complications, was significantly higher in patients who received combined treatment (vertebral artery stenting in combination with drug therapy). The survival rate of patients from group I, free from restenosis, was 94.12±4.03%. In general, restenosis in 6.45% of patients in the combination treatment group, however, restenosis itself did not affect the incidence of major cerebral complications in the long-term period (χ2=0.6911; p=0.4057). Conclusion In patients with “assymptomatic” atherosclerotic lesions of the vertebral arteries and with factors of poor prognosis of cerebral artery diseases, secondary prevention of cerebrovascular events is advisable to carry out a combined method, including stenting of the vertebral arteries, in combination with drug therapy. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Russian academic excellence project 5-100

Clinical characteristics of transient vision disorders and arterial hypertension.

A study of 104 patients with a transient ischemic attacks (TIA) in the form of visual disorders was conducted to assess the factors that affect the development and probable localization of TIA. Neurological and ophthalmological status, structural characteristics of the brain and major arteries of the head (MAH) with the use of magnetic resonance therapy (MRT) and ultrasonic dopplerography were assessed. The age of patients ranged from 33 to 79 years (65.4 years in average). The control group consisted of 46 patients with an average age of 67.8 years without cerebral ischemic events and visual disorders. During the MRI, the presence of microstructural pathology of the brain was assessed; “leukoaraiosis” was considered; foci up to 2-3 mm that are vascular by genesis. Significant differences in the frequency of TIA occurrence in terms of gender were not detected in all age subgroups. In young patients with TIA, arterial hypertension was associated with signs of microstructural pathology (MSP) of the brain in 85.58% cases. TIA localization did not correlate with the grade of structural disorders of the MAH and the nature of retinopathy in all age groups. Frequency of TIA tended to increase (in the a. ophthalmica pool) with an increase in the grade of stenosis of the MAH and retinopathy. The control group had retinopathy of the 1st stage in 12 or 26.09%, showing a qualitative difference with the group of study. The study did not reveal any differences in the frequency of TIA (according to presentations to a medical institution) in patients of different age groups, which indicates the influence of others factors that are not related to aging, such as TIA factors. The state of the MAH and microcirculation of vessels are their markers and probable causative factors. Determination of markers for the prognosis of the deve­lopment of cortical TIA or TIA in a. ophthalmica pools are still an open issue, as well as the chances of the TIA development in other areas of cerebral blood supply. Thus, according to clinical and anamnestic data, transient ischemia in the patients, who have applied to medical institutions with complaints of transient vision disorder (impairment) and who have been diagnosed with TIA is detected mainly in the a. ophthalmica blood supply pool (89 or 85.58%), more rarely (in 15 or 14.42%) in the cortical areas of visual analyzer without gender and age differences. All age groups had TIA associated with MAH structure impairment, retinopathy, MSP of the brain (in 82% of men and 67% of women), this leads to the interpretation of such TIA as non-random events preceded by systemic disorders, which are the basis for the prediction and prevention of such conditions.

Self-Determination Theory Application In The Discharge Of Patients With Transient Ischemic Attack

Background: The principle of transient ischemic attack treatment is lifestyle modification and pharmacological treatment that would reduce recurrence and incidence of stroke. Lifestyle changes require follow-up care and continuity of nurse and patient relationships, but the current training does not meet this need. The trainings based on motivating theory such as self-determination, besides continuity of the relationship with patient, improve his/her incentive, specially of it is carried out at the discharge time. Therefore, this study has been done by the purpose of defining the impact of discharge plan based on self-determination theory on the lifestyle patients with transient ischemic attack.Methodology: The analysis has been done on 57, 18-90 years old clinical random patients in Tehran hospitals (29 cases and 28 controls) in 2015. Data were collected by demographic questionnaire at the beginning and health-promoting lifestyle questionnaire(second edition) were collected at the end of the study. Discharge plan based on self-determination theory, including patients and families meeting in hospital and telephone counseling during the 12 weeks after discharge was accomplished in cases group. The control group received only routine hospital care. Data were analyzed by t-test and chi- squre test.Results: The score of lifestyle was similar in both groups (p&gt; .05) at beginning of the study, but at the end of the study, the average score of cases group (17.1 ± 164.2) significantly higher than the control group (17.6 ± 118.3) (p &lt; 0.001). Furthermore, At the end of study, the mean scores of nutrition, physical activity, stress management, interpersonal relationships, spiritual growth and responsibility in the lifestyle cases group was significantly higher than the control group (p &lt;.001). The frequency of transient ischemic attacks after discharge in the cases group (13.8%), significantly lower than the control group (46.4%), respectively (p = .016).Conclusion: By executing discharge plan based on self-determination theory, transient ischemic attack patients lifestyle score increased to 26.7% and the frequency of transient ischemic attacks32.6% reduces. So use this simple and accessible program in the care of patients with ischemic attack is recommended.

Multiple encephalogaleoperiosteal synangiosis for bilateral carotid artery stenosis in a 13-year-old girl: a case report

Encephalogaleoperiosteal synangiosis (EGS) has been widely used to treat children with moyamoya disease (MMD). We present the first case of successful multiple EGS in a patient with brain ischemic disease who presented with different cerebrovascular findings from MMD. A 13-year-old girl had an increased frequency of transient ischemic attacks that affected her right extremities. Digital subtraction angiography showed tapering of the internal carotid artery (ICA). The anterior cerebral artery (ACA) and middle cerebral artery (MCA) were visible on vertebral angiogram, but not on carotid angiogram. The intact circle of Willis and lack of hypervascularity of the lenticulostriate arteries were observed. Decreased regional cerebral blood flow (CBF) in the bilateral ACA and MCA territories quantified by (123)I-N-isopropyl-p-iodoamphetamine-single photon emission computed tomography indicated the need for extracranial-intracranial bypass surgery. Multiple EGS procedures were performed instead of direct anastomosis, which is the standard procedure for intracranial ICA stenosis, because the space for the craniotomy was limited by transdural anastomosis. Despite the fact that the diagnosis of MMD was questionable, the hemispheres were well vascularized, and the neurology and CBF improved postoperatively. The preserved circle of Willis and lack of moyamoya vessels were inconsistent with the features of MMD. However, childhood onset, bilateralness, chronic intracranial ICA stenosis, and transdural anastomosis indicated the same underling pathogenicity as MMD. It is hypothesized that ICA stenosis occurred immediately proximal to the posterior communicating artery in this case. This would have produced the atypical finding of the remaining circle of Willis without growth of the basal moyamoya vessels.

Abstract W P122: Comparison Of Clinical And Radiological Outcomes Between Distal And Proximal Protections Performed During Carotid Artery Stent Interventions

Background &amp; objective: We evaluated the differences of the clinical deteriorations, distal migration of emboli, and approximation of stent to vessel between the patients who received distal or proximal protections to prevent distal migration of emboli during carotid artery stent interventions (CAS). Methods: We retrospectively analyzed clinical and radiological data of 70 patients (Distal-Protection Group), who underwent CAS using distal protection (FilterWire EZ TM , Boston Scientific), and 65 patients (Proximal-Protection Group), who using proximal protection (MO.MA® Ultra, Medtronic). The frequency of transient ischemic attacks (TIA) during CAS, the number and frequency of new lesions on post-CAS diffusion weighted image (DWI), and the ratio of the remained-area from outer stent wall to inner vessel wall measured by post-CAS carotid sonogrphy was compared between two groups. Results: Proximal-Protection Group showed significantly higher TIA occurrences during CAS (Distal-, 5 [7%]; Proximal- Protection Group, 19 patients [31%], p&lt;0.001). On post-CAS DWI evaluation, total number (Distal-, 4.8±4.6; Proximal-Protection Group, 4.3±5.6, p=0.712) and incidence (Distal-, 29 [40%]; Proximal-Protection Group, 18 patients [29%], p=0.207) of the new DWI lesions were similar between the two groups. Major infarctions (Distal-, 5 [7%]; Proximal-Protection Group, 2 patients [3%], p=0.278) observed on ipsilateral cortex or internal borderzone area were more frequent on Distal- than Proximal-Protection Group without statistical significance. Both groups showed similar ratio of the remained-area from stent to vessel on post-CAS sonography (Distal, 0.33±0.18; Proximal-Protection Group, 0.28±0.15, p=0.072). Conclusions: The present differences in clinical and radiological parameters between different protection methods should be the factors to choose appropriate protection device during CAS.

Cerebral CTPI and head and neck CTA feature of patients with transient cerebral ischemia and its correlation with clinic

Objective To investigate the head and neck CTA findings and cerebral CTPI in patients with transient ischemic attack(TIA), and their relationship with frequency of TIA, duration and CTA detected responsible vessels. Methods 180 TIA patients were selected as the research subjects, the GE Lightspeed 64 spiral CT perfusion CT scan and CTA examination were taken, and the differences in CTPI parameters measurement, head and neck artery disease of patients were analyzed. To observe the correlation between CTPI perfusion abnormalities in patients with TIA seizure frequency, duration and NIHSS score. The CTPI perfusion abnormalities and consistency of CTA display of responsible vessels were analyzed. Results The positive rate of CTPI examination was 75.56%,that of CTA examination was 81.11%.The positive rate of patients(NIHSS≥4 points)with CTPI was 88.89%,which was higher than 66.67% in patients(NIHSS<4 points) with CTPI(χ2= 6.87,P<0.05).The positive rate of patients(seizures time≥10min)with CTPI TIA was 71.43%, which was higher than 45.45% of the patients(seizures time< 10min) with CTPI(χ2= 7.23,P< 0.05).The CTPI positive rate of patients with the TIA seizure frequency≥2 times/d was 83.33%, which was higher than 61.67% of patients with the seizure frequency<2 times/d(χ2= 5.48,P<0.05).The CTPI positive and CTA responsibility vascular consistent proportion was 73.33%,which was significantly higher than 26.67% of both inconsistent and negative(χ2= 19.43,P< 0.01). Conclusion The cerebral CTPI and head and neck CTA can response to TIA in patients with intracranial lesions accurately, consistency and clinical manifestations are very good, which have higher value in clinical application. Key words: Tomography, X-ray computed; Perfusion imaging; Cerebral angiography; Ischemic attack, transient; Stroke

Clinical study of PTAS therapy for patients with ischemia cerebrovascular disease caused by artery stenosis

The curative efficacy of percutaneous transluminal angioplasty and stenting (PTAS) in the treatment of patients with ischemia cerebrovascular disease caused by artery stenosis was explored. The clinical data of 111 patients with ischemia cerebrovascular disease receiving PTAS in Guangdong Province General Hospital from Aug. 2007 to Nov. 2009 were retrospectively analyzed. In total 132 stents were implanted in the 111 patients. The mortality and rate of neural and non-neural complications were assessed perioperatively. Outcomes [including the frequency of transient ischemic attack (TIA), stroke, or death from vascular diseases) were assessed after operation. NIHSS rating was performed in all cases before and at first week, 6th month and 12th month after the operation. The PTAS success rate was 100%. The degree of stenosis was reduced after PTAS. The total complication rate during perioperative period was 15.3% (the rate of neural complications was 3.6%). Sixty-seven patients were followed up. Three patients (4.48%) developed cerebrovascular events within 1 month, containing one case of TIA, one case of ipsilateral mild stroke and one case of contralateral mild stroke. No severe stroke or death was observed. During a follow-up period of 12 months 7 patients had cerebrovascular events (10.44%), including 2 cases of ipsilateral TIA (2.99%), 2 cases of ipsilateral mild stroke and 2 cases of contralateral mild stroke (2.99%), one case of severe stroke (1.49%). In 13 patients receiving DSA re-examination one year after PTAS, 2 patients (15.38%) had in-stent restenosis. NIHSS scores were obviously decreased during a follow-up period as compared with those pre-operation (P<0.05). It was concluded that PTAS could significantly alleviate the neural function deficit of the patients with ischemia cerebrovascular disease. The success rate of PTAS was high, and the rate of complications was lower and the clinical outcomes were satisfactory. PTAS is a safe and effective therapeutic method, though the long-term outcomes need further study.

Evaluation of Cerebral Hemodynamics with Perfusion MRI in Childhood Moyamoya Disease

The purpose of our study was to evaluate the role of perfusion MRI and to compare the findings with those of conventional imaging in childhood moyamoya disease (MMD). Perfusion MRI was performed preoperatively on 13 cases of childhood MMD. Based on the perfusion MRI findings, patients were classified into four groups: those with normal regional cerebral blood volume (rCBV) and time to peak (TTP) (group 1, n = 2); those with normal rCBV and delayed TTP (group 2, n = 1); those with increased rCBV and delayed TTP (group 3, n = 5), and those with decreased rCBV and delayed TTP (group 4, n = 5). Lesion volume as determined using the rCBV map was compared with that on MRI and single photon emission computerized tomography (SPECT). The characteristics of groups 1, 2 and 3 were a high frequency of transient ischemic attacks, normal finding on MRI, early angiographic stages, decreased reserve on SPECT and favorable operative outcome. In group 3, angiography revealed abundant collateral channels. In group 4, all cases had infarction on MRI and abnormal perfusion on SPECT. Angiographic stages tended to have progressed, and operative outcome was less favorable. Perfusion MRI documented hemodynamic asymmetries in the five cases with normal MRI. Perfusion MRI is suggested to have a sensitivity intermediate between rest and acetazolamide SPECTs. We conclude that perfusion MRI may be a valuable tool for characterizing and monitoring ischemia in MMD. Perfusion MRI provides additional functional information not available from conventional MRI and has a potential role comparable to SPECT in the evaluation of MMD.

Frequency of transient ischaemic attacks in strokes: place for a preventive treatment.

Transient ischaemic attack (TIA) represents a neurological deficit during less than 24 hours, without any abnormality on CT scan. This symptom may have 2 risks: it may give place to a severe stroke, and it is not always linked to an ischaemic mechanism. This work rests on a population-based registry existing in Dijon since 1985 with a specific and exhaustive registration. CT scan allows the mechanisms of stroke to be identified: cortical infarct, lacunar infarct, cerebral haemorrhage, and TIA. TIA represent 15% of stroke. Survival rate of 80% is better than other strokes. A TIA may appear before a cerebral infarct in 48% of the cases, a lacunar infarct in 18% of the cases, another TIA in 28% of the cases, and a haematoma in 8% of the cases. Therefore TIA is an important symptom appearing before severe stroke, that may let place to a preventative action.

Diabetes and Hypertension

Diabetes mellitus and hypertension constitute two powerful independent risk factors for cardiovascular, renal and atherosclerotic disease. The frequent occurrence of the two diseases in the same individual doubles the risk of cardiovascular death, as well as substantially increasing the frequency of transient ischemic attacks, strokes, peripheral vascular disease with lower extremity amputations, as well as end-stage renal disease and blindness. Although hypertension usually occurs in IDDM in association with renal disease, in NIDDM the evolution of hypertension appears to be multifactorial and independent of renal disease. Obesity appears to be dissociable from hypertension and NIDDM with a common link between obesity, hypertension and NIDDM appearing to be hyperinsulinism and insulin resistance. It has been suggested that hyperinsulinism and insulin resistance may lead to hypertension through altered intracellular calcium metabolism, enhanced renal sodium reabsorption, or through an effect of insulin upon lipid and/or catecholamine metabolism. Further, insulin itself may have a direct effect upon the atherosclerotic process in the hypertensive diabetic patient. These considerations have been taken into account in the structuring of antihypertensive therapy in Type I and Type II Diabetes Mellitus.

Carotid endarterectomy in patients with transient cerebral ischaemia

A randomised controlled trial of endarterectomy in patients with carotid artery disease showed that operation significantly reduced the frequency of transient ischaemic attacks (TIA) in the relevant vascular territory. Because of the high post-operative morbidity in the surgical group, the trial was abandoned before conclusions could be drawn as to the influence of endarterectomy on long-term survival or on the incidence of subsequent strokes.

Mechanisms of acute carotid stroke

In a three-year study, the clinical course and results of intracranial angiography were compared in patients having an acute stroke in the carotid artery territory combined with angiographic abnormalities indicating severe extracranial carotid stenosis or occlusion. Two major mechanisms of stroke were delineated. In one group, the angiographic intracranial abnormalities strongly suggested the presence of embolism in the cerebral vessels supplied by the stenotic or occluded carotid artery; many of these patients had no obvious transient ischemic attacks prior to their stroke and experienced a moderate to severe clinical deficit. In the other group, evidence of embolism was absent; many showed a widespread delay in cerebral arterial perfusion, experienced a greater frequency of transient ischemic attacks before their stroke, and had a milder stroke than did those with embolism.

The value of carotid endarterectomy in treating transient cerebral ischemia of the posterior circulation.

The results of a retrospective study of patients undergoing carotid endarterectomy for hemispheric and/or nonhemispheric symptoms of transient ischemic attacks are presented. During an approximately 3-year period of follow-up observation, recurrent cerebral ischemia following carotid endarterectomy was two to three times more frequent among patients with nonhemispheric transient ischemia than among those with hemispheric transient ischemia. Patients with symptoms of both hemispheric and nonhemispheric transient ischemia had the highest frequency of transient ischemic attacks and stroke during the follow-up period and also had the greatest surgical morbidity and mortality. The results of this study suggest that carotid endarterectomy has little or no therapeutic value in treating patients with vertebral-basilar ischemia.

Long-term anticoagulant therapy for TIAs and minor strokes with minimum residuum.

One hundred seventy-eight patients with transient ischemic attacks (TIAs) or small strokes with slight symptoms persisting for more than 24 hours (incomplete recovery = IR) (TIA-IR) from both the carotid and the vertebrobasilar systems were treated with anticoagulants. Ten patients stopped the treatment because of severe side effects. Only one patient had a lethal cerebral infarction when the thrombotest values were above the therapeutic level; no other infarction happened during the treatment period. Moreover, the frequency of TIA decreased during the treatment, compared with descriptions of the natural course of TIA. One hundred four patients were observed for a mean of 21 months after the anticoagulant treatment ended. During the observation period, six patients had cerebral infarctions. This was a sixfold increase compared with the stroke incidence during treatment, and was almost identical with the incidence of strokes seen during the natural course of TIA. All the cerebral infarctions were in patients who had their initial TIA/TIA-IR from the carotid territory (within the same carotid artery which earlier had given symptoms). The investigation shows that long-term anticoagulant treatment is useful, especially in patients with carotid TIA/TIA-IR, and that this treatment should continue as long as the patients can manage it. In patients with vertebrobasilar symptoms of malignant character, it seems feasible to terminate the treatment after about one year. The mechanism of the anticoagulant treatment is obscure, but it does not appear to influence the progress of the atherosclerotic process.

Transient ischemic attacks due to atherosclerosis. A prospective study of 160 patients.

Patients with transient ischemic attacks (TIAs) due to atherosclerosis were studied by aortocranial arteriography. Onset of TIAs was before age 55 in 24% and between 55 and 64 in 47%. Men exceeded women by two to one. Of 160 patients, 77 were treated medically and 82 surgically. Five died in the immediate postoperative period. In the survivors, mortality has been the same in the medically and surgically managed groups. For patients with multiple lesions, surgical reconstruction of the carotid arteries was associated with very high surgical risk. In the medically treated group, anticoagulant therapy reduced the frequency of TIAs, but did not appear to protect patients from stroke. Mortality was 23% at four years, 57% of deaths being attributable to myocardial infarction and 38% to stroke.

Transient ischemic attacks and risk of stroke in an elderly poor population.

The significance for stroke and correlates of transient ischemic attacks (TIA) were studied prospectively in a population of 2,772 persons aged 65 to 74. The prevalence of TIA at the beginning of the study was 63 per 1,000. TIA prevalence was substantially higher among blacks and women than among whites and men. Only 13% of those with TIA were free from any other major evidence of cardiovascular disease. White men, black men and black women with TIA had higher observed incidence rates of stroke than those without TIA. White women were a notable exception to this trend. There was a positive association between frequency of TIA and risk of stroke. Those with TIA and hypertension experienced higher stroke incidence rates than normotensive persons with TIA.