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

A Study on First Ischemic Stroke Patients for Prevalence of Extracranial Carotid Artery Stenosis and Risk Factors: Our Experience in Northeast India and Review of Literature

Objective:

To assess the prevalence of carotid artery stenosis and risk factors in stroke patients of northeast India. This is a prospective hospital-based study on 157 first ischemic stroke patients of the region.

Method:

A total of 157 patients presenting with first ever sudden onset focal neurological deficit lasting for more than 24 hours due to acute ischemic brain infarction were selected, after excluding other causes of focal neurological deficit by imaging. All extracranial carotid arteries were evaluated with carotid ultrasonography. Forty-four patients also had computed tomography (CT) angiography of intracranial and extracranial arteries. Risk factors of stroke were recorded for each patient.

Results:

Only 8.92% patients had significant extracranial carotid artery stenosis. There was high prevalence of intracranial artery stenosis compared to extracranial artery stenosis in patients who had CT angiography. There was high prevalence of hypertension, dyslipidemia, and diabetes. Increased age and male sex were important factors associated with first ischemic stroke.

Conclusion:

The prevalence of significant extracranial carotid artery stenosis is low in northeast Indian patients with first ischemic stroke, indicating that it is not a major cause of ischemic stroke in this population. There may be high prevalence of intracranial artery stenosis compared to extracranial artery stenosis.

Is Management of Central Retinal Artery Occlusion the Next Frontier in Cerebrovascular Diseases?

Central retinal artery occlusion (CRAO) is a medical emergency that, if not treated, may result in irreversible loss of vision. It continues to be an important cause for acute painless loss of vision. Amaurosis fugax or "transient CRAO" has long been considered an equivalent of transient cerebral ischemic event. Animal models, in addition to data from retrospective and randomized clinical studies, provide valuable insights into the time interval for irreversible retinal ischemia. Subset analyses from 2 large studies of patients with CRAO show benefit from treatment with thrombolysis within 6 hours from symptoms onset. Significant workflow improvements after the intra-arterial therapy trials for acute ischemic stroke have occurred world over in last 5 years. Patients with CRAO are uniquely suited to receive maximum benefits from the changes in workflow for treatment of patient's acute ischemic stroke. Just as in clinical triage of acute ischemic stroke, correct and timely diagnosis of patients with CRAO may help in preventing visual loss. The approach to acute ocular ischemia should mimic that used for acute brain ischemia. Comprehensive stroke centers would be ideal triage centers for these patients in view of availability of multidisciplinary participation from vascular neurology, neuroendovascular surgery, and ophthalmology. Time is Retina!

Stroke: epidemiology, clinical picture, and risk factors--Part I of III

The aim of this review is to present the current knowledge regarding stroke. It will appear in three parts (in part II the pathogenesis, investigations, and prognosis will be presented, while part III will consist of the management and rehabilitation). In the current part (I) the definitions of the clinical picture are presented. These include: amaurosis fugax, vertebrobasilar transient ischemic attack, and stroke (with good recovery, in evolution and complete). The role of the following risk factors is discussed in detail: age, gender, ethnicity, heredity, hypertension, cigarette smoking, hyperlipidemia, diabetes mellitus, obesity, fibrinogen and clotting factors, oral contraceptives, erythrocytosis and hematocrit level, prior cerebrovascular and other diseases, physical inactivity, diet and alcohol consumption, illicit drug use, and genetic predisposition. In particular, regarding the carotid arteries, the following characteristics are analyzed: atheroma, carotid plaque echomorphology, carotid stenosis, presence of ulcer, local variations in surface deformability, pathological characteristics, and dissection. Finally the significance of the cerebral collateral circulation and the conditions predisposing to cardioembolism and to cerebral hemorrhage are presented.

Rapidly progressive stroke in a young adult with very low high-density lipoprotein cholesterol

Ischemic strokes can affect young adults (15-45 years old). Most such strokes are caused by cardioembolic events, small vessel disease, or illicit drug use, and less frequently by large vessel atherosclerosis. Large vessel cerebral atherosclerosis is usually associated with high levels of low-density lipoprotein (LDL) cholesterol, but a low level of high-density lipoprotein (HDL) is also a risk factor for ischemic strokes. The magnitude of increased risk is unclear, particularly with extremely low HDL levels found only in various genetic and inherited disorders. Advanced atherosclerosis developed in the patient in this study, with HDL of 3 mg/dL, leading to rapidly progressive stroke with a fatal outcome. The disease primarily affected the posterior circulation. The course of this case illustrates that very low HDL may be associated with advanced cerebrovascular atherosclerosis and fatal stroke, and as such should be considered in young individuals with stroke.

Adrenoleukodystrophy: increased plasma content of saturated very long chain fatty acids. 1981

With a new method we measured the saturated very long chain fatty acids in the plasma of adrenoleukodystrophy (ALD) hemizygotes, ALD heterozygotes, and controls. ALD hemizygotes showed increased levels of hexacosanoate (C26 fatty acid) which represented 0.081 ± 0.0066% (SEM) of total fatty acids, compared to 0.015 ± 0.0032% in the controls. C25, C24, and C23 fatty acids were also increased, but the C22 and C20 fatty acids were normal. C26 levels were also increased in most ALD heterozygotes, with a mean level 0.057± 0.0063% of total fatty acids. The technique can be used for diagnosis and carrier identification, and in the evaluation of therapy.

Intimal medial thickening of common carotid artery as indicator of coronary artery disease

The authors investigated the relation between coronary atherosclerosis, angiographically detected, and intimal-medial (I-M) thickening of the common carotid artery (CCA), as measured by high-resolution B-mode ultrasound system. They studied 31 patients with coronary artery disease (CAD) and 23 healthy control subjects. I-M thickening of CCAs and atheromatous plaques at the carotid bifurcation were evaluated. A score system was defined (range 0-20) based on the absence or presence of atherosclerotic lesions at common and internal carotid arteries. A coronary angiography score was defined based on the presence of of atherosclerotic lesions at nine coronary arterial segments (range 0-36). The thickness of CCAs (M +/- SD) in CAD patients was significantly higher (1.45 +/- 0.95 mm) than in controls (0.87 +/- 0.10 mm, P < 0.005), and an I-M thickening of 1.1 mm or more was specific and positively predictive of CAD. A significant positive correlation between coronary and carotid score was observed (P < 0.028, r = 0.373). The study suggests that I-M thickening could be helpful for the identification of patients at risk for CAD.

Peripheral nerve abnormalities in adrenomyeloneuropathy: a clinical and electrodiagnostic study

Adrenomyeloneuropathy (AMN) is one of the most frequent phenotypes of X-linked adrenoleukodystrophy. Whether the polyneuropathy in AMN results from primary demyelination or axonal degeneration is uncertain. We examined 23 patients (18 men with AMN and five female carrier with AMN symptomatology), performed electroneurography and EMG, and compared our results with standardized electrodiagnostic criteria for primary demyelination. Both clinically and electrodiagnostically, the lower extremities were most frequently and most severely affected. A longer duration of symptoms was related to more severe pyramidal dysfunction (p < 0.004) and spasticity (p < 0.04), and to a more severe impairment of vibration sense (p < 0.05). There were on correlations between the different electrophysiologic studies and the duration of neurologic symptoms. Only two AMN patients (9%) fulfilled the electrodiagnostic criteria for primary demyelination. However, both had abnormally low compound muscle action potentials, which may have been a reflection of primary axonal degeneration. Six other patients (26%) partially fulfilled the criteria for primary demyelination, of whom five also manifested low compound muscle action potentials. In 15 patients (65%), we found polyneuropathy with predominantly axonal, sensorimotor features. We conclude that the neuropathy in AMN patients is due to primary axonal degeneration.

Carotid endarterectomy in the presence of a contralateral occlusion: a review of 315 cases over a 27-year experience

Recent data from the North American Symptomatic Carotid Endarterectomy Trial revealed a 14.3% perioperative risk of stroke or death with carotid endarterectomy contralateral to a carotid artery occlusion. Since last reporting on this topic in the mid-1980s, the authors have reviewed 180 patients with occlusion of one internal carotid artery (ICA) and who underwent endarterectomy of the stenotic contralateral ICA operated from 1965 to 1984 (group A) compared with 135 operated on from 1985 to 1991. The two groups were similar with respect to age, sex, incidence of coronary artery disease, hypertension, diabetes and history of smoking, but group B had a significantly increased incidence of patients who were neurologically symptom-free before surgery (21.5% versus 7.8%, P < 0.001). The combined perioperative stroke or death rate for patients in group B was significantly lower than for those in group A (0.7% versus 6.7%, P < 0.01). Comparison of the operative techniques showed more frequent placement of intra-arterial shunt (52.6% versus 29.4%, P < 0.001) and increased use of general anesthesia (20.0% versus 9.4%, P < 0.01) in patients of group B. Analysis of the etiology of the complications, however, showed that shunting alone could not account for the improved results. Lower incidences of postoperative thrombosis, embolization and intracerebral hemorrhage were equally important.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors affecting survival and occurrence of stroke in patients with transient ischemic attacks

OBJECTIVE

To assess the predictive value of a series of demographic and clinical variables for stroke and survival in a population after a first transient ischemic attack (TIA).

DESIGN

Cox proportional hazards regression analysis was used to determine the association of various demographic and clinical factors with survival and stroke in 330 residents of Rochester, Minnesota, who had an initial TIA with first medical attention within 120 days during the period 1955 through 1979.

MATERIAL AND METHODS

We investigated several demographic, diagnostic, and treatment variables, including initial clinical manifestations (pure sensory TIA and unilateral carotid hemispheric TIA), to estimate the significant (P < or = 0.01) predictors of survival and of stroke. Follow-up was limited to 10 years.

RESULTS

Relative survival for patients with a first TIA was 94% at 1 year and 87% at 5 years after first medical attention. Three interactions were significant predictors of survival: (1) age at TIA and gender (young women had the best survival and older women had the worst survival), (2) systolic blood pressure and congestive heart failure (patients with low systolic blood pressure and congestive heart failure had the worst survival), and (3) calendar year of onset and diabetes mellitus (survival was worst for patients with diabetes during the early years of the study). Only age was a significant independent predictor of stroke after TIA (hazards ratio, 1.45 per 10 years).

CONCLUSIONS

Estimating risks of stroke and death after TIA on the basis of demographic and clinical variables without reference to the mechanism of TIA is of limited clinical utility. Age is the most significant such predictor. Interactions that reflect comorbidity, such as diabetes, blood pressure abnormalities, or heart disease, may affect survival but not the risk for occurrence of stroke.

Diabetes and stroke

Diabetes is a major risk factor for development of ischemic cerebrovascular disease. Patients with diabetes are at least two times more likely to have a stroke than nondiabetics. In addition, they are more likely to suffer increased morbidity and mortality after stroke. The mechanism of production of stroke secondary to diabetes may be due to cerebrovascular atherosclerosis, cardiac embolism, or rheologic abnormalities. The evaluation of cerebrovascular disease in diabetic patients is similar to the nondiabetic patient, with particular attention paid to adequate hydration prior to the administration of contrast agents. Treatment options for stroke in diabetics requires individualization but should include risk factor modification, and may include platelet antiaggregants, anticoagulation, or, in a well-defined subgroup, carotid endarterectomy.

Relation of extent of extracranial carotid artery atherosclerosis as measured by B-mode ultrasound to the extent of coronary atherosclerosis

The extent of carotid artery atherosclerosis as measured by B-mode ultrasound has been shown to be strongly and independently correlated with the presence or absence of coronary atherosclerotic disease (CAD), but no studies to date have used carotid B-mode ultrasound to compare the extent of atherosclerotic disease in the two arterial circulations. We used data from a registry of patients undergoing cardiac catheterization and B-mode ultrasound of the carotid arteries to compare the extent of CAD (number of major coronary vessels with 50% or greater stenosis as judged by a consensus interpretation) with the extent of extracranial carotid atherosclerosis. Four hundred thirty-four patients (234 men, 200 women) greater than 40 years of age were stratified by gender and then divided into quartiles on the basis of a B-mode score that was derived by summing arterial wall thickness at nine sites in the left and nine sites in the right carotid arteries. Evaluation of extent of CAD for the four B-mode quartiles showed that men in the lowest B-mode quartile were over six times more likely to have normal coronary arteries than three- to four-vessel CAD, while men in the highest B-mode quartile were over 10 times more likely to have three- to four-vessel CAD than normal coronary arteries. The findings were similar for women but not as dramatic. Gender-specific discriminant function models using traditional risk factors alone or in combination with B-mode score were developed to predict the extent of CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

A methodological appraisal of research on prognosis after transient ischemic attacks

We analyzed existing research on the prognosis of patients who have had a transient ischemic attack to identify studies that adhere to basic methodological principles and to identify underinvestigated questions. Studies were eligible for analysis if they were published in peer-reviewed journals after 1950, written in English, and included at least 50 patients with transient ischemia. Studies that included patients with stroke were included only if they reported outcome rates separately for the subgroup of patients with transient ischemia. All eligible studies were extracted by one investigator who recorded adherence to six key methodological principles. Among 60 eligible studies, 54 were observational cohort studies and six were randomized trials. Adherence to the six methodological principles was as follows: eight studies included an adequate description of diagnostic criteria and of procedures used to assure adherence to the criteria, 54 used appropriate end points, two assembled inception cohorts, 10 included an adequate description of end point surveillance, 22 adequately reported and analyzed censored patients, and 10 included a multivariate analysis for predictive variables. No study adhered to all six principles, but two adhered to the three most important ones (appropriate end points, inception cohort, and adequate reporting and analysis of censored patients). Aspects of prognosis after transient ischemia that have not been completely investigated include the severity of subsequent strokes and methods for estimating the outcome risk for individual patients. We conclude that only a few published investigations on prognosis after transient ischemia are methodologically complete. This finding helps explain why it is difficult to interpret many studies. Further research is needed and should target underinvestigated topics.

A simple method to improve the accuracy of non-invasive ultrasound in selecting TIA patients for cerebral angiography

A prospective study is reported of the ability of B mode ultrasound imaging and continuous wave Doppler flow studies to detect different degrees of stenosis of the extracranial internal carotid artery (ICA) in 186 arteries in 99 patients with transient ischaemic attacks (TIA) and minor ischaemic stroke. A simple mathematical equation has been developed which combines the image and flow data to provide a single predictor of the degree of angiographic stenosis which has advantages over either ultrasonic modality used alone. The sensitivity and specificity of the predictive model in the detection of stenosis greater than or equal to 25% was 73% and 98%, of stenosis greater than or equal to 50% was 90% and 93%, of stenosis greater than or equal to 75%, 65% and 99% and occlusion 100% and 94% respectively. The principal clinical value of ultrasound screening is to spare patients with "non-significant" stenosis the risk of unnecessary angiography. Thus a simple measure of the Duplex screening tests' performance is the proportion of all strokes occurring as a complication of angiography that are avoided by changing the investigation policy from "angiograms for all carotid TIA and minor ischaemic stroke patients" to "angiograms for all patients with abnormal ultrasound results". If Duplex scanning were used to select patients most likely to have a significant abnormality on angiography, depending on the degree of stenosis to be detected, 52-85% of angiographic strokes might be avoided. If the predictive equation were used 62-88% of angiographic strokes might be avoided.

Antithrombotic treatment of cerebrovascular disease

The most common type of cerebrovascular disease is ischaemia or infarction from atherothrombosis or cardiac embolism. Antithrombotic treatment with an antiplatelet agent or anticoagulant assumes a prior clinical classification into categories of transient ischaemic attack (TIA) or minor stroke, acute partial stable stroke, stroke-in-progression, and completed stroke. Aspirin reduces the risk of stroke, myocardial infarction, and death after TIA or minor stroke secondary to atherothrombosis. Aspirin is effective in both sexes at a dose of 300 or 1200 mg/day. Ticlopidine (500 mg/day), a new antiplatelet agent, is more effective than aspirin in preventing stroke and death in patients with TIA or minor stroke. Ticlopidine (500 mg/day) is effective in preventing recurrent stroke, myocardial infarction, or vascular death in patients with completed stroke. Aspirin has not been directly shown to be effective after completed stroke. No clear evidence exists for the use of anticoagulants in atherothrombotic cerebral vascular disease in patients presenting with TIA or minor stroke, acute partial stable stroke, stroke-in-progression, or completed stroke. Anticoagulation for rheumatic valvular heart disease is effective in preventing recurrent embolism. Long-term anticoagulation of patients with mechanical prosthetic valves protects against initial embolism and prevents recurrent embolism. The addition of aspirin (500-1000 mg/day) to warfarin reduces the rate of cerebral embolism from mechanical prosthetic heart valves but is associated with increased bleeding. The addition of dipyridamole (400 mg/day) to warfarin may be more effective than aspirin in reducing the rate of cerebral embolism from mechanical prosthetic heart valves and has fewer bleeding side-effects. Anticoagulation during the hospital phase of myocardial infarction reduces the incidence of systemic embolism/stroke. Long-term anticoagulation of patients after the hospital phase of myocardial infarction reduces the incidence of systemic embolism/stroke, recurrent myocardial infarction and death. Prophylactic anticoagulant treatment of patients with non-valvular atrial fibrillation reduces the incidence of embolism, but the optimal duration of treatment is not known. Immediate anticoagulation of patients with completed cardioembolic stroke is safe and effective in preventing recurrent embolism.

Long-term results after carotid endarterectomy for carotid artery stenosis with contralateral occlusion

Patients with one internal carotid artery occlusion and a contralateral stenosis run a significantly higher risk of stroke. We performed endarterectomy of the stenotic carotid in 44 such patients and followed them for mean 54 months (range 1-172 months). Early mortality was 2%. Life-table analysis shows that the incidence of a new stroke was 0.6% per year, the survival rate was 78% after three years, and 70% after five years. We conclude that carotid endarterectomy can be safely performed in patients with contralateral internal carotid artery occlusion and can significantly improve the long-term prognosis of these patients.

Risk factors and clinical manifestations of pathologically verified lacunar infarctions

Review of 2,859 autopsy reports disclosed lacunar infarctions in 169 patients (6%). Review of the charts of 167 of these patients revealed hypertension in 64%, diabetes in 34%, smoking in 46%, and no known risk factor for cerebrovascular disease in 18%. As many as 81% of the patients with lacunes were asymptomatic. Symptomatic lacunes presented most commonly as pure motor hemiparesis (31%), aphasia plus right hemiparesis (20%), or sensorimotor dysfunction (11%); none presented as pure sensory stroke. These results suggest that the spectrum of lacunar infarction is more heterogeneous than previously thought. Most lacunes are asymptomatic, and the majority of symptomatic patients do not present with "classical" lacunar syndromes.

Current management of the patient with internal carotid artery occlusion

Despite the recent controversy concerning surgical therapy of patients with carotid artery disease, rational therapeutic plans can be developed based on available data. The patient who is symptomatic from occlusion of one or both internal carotid arteries is at particularly high risk for development of stroke and can ill-afford indecision. All symptomatic patients, therefore, with any of the extracranial occlusive disease patterns described are potential surgical candidates. Conversely, among the asymptomatic patients with these same patterns of occlusion, only those with internal carotid occlusion and contralateral stenosis should be considered for surgical therapy. Treatment must be individualised and directed at revascularising stenotic (not occluded) internal carotid arteries, or important collateral vessels such as the external carotid artery and in fewer cases the vertebral artery. The asymptomatic patient with unilateral internal carotid artery occlusion and no contralateral lesions should be monitored closely with Duplex scanning for development of a contralateral stenosis. When a stenosis of 80% or greater is encountered, strong consideration should be given to prophylactic endarterectomy in these patients due to their high risk for stroke. Endarterectomy for a 50-60% stenosis may also be reasonable in a single patent internal carotid artery. In the absence of a significant contralateral stenosis, no treatment is necessary. Individuals with internal carotid artery occlusion and symptoms referable to a contralateral carotid stenosis should also be managed with endarterectomy of the stenotic carotid artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Pitfalls during carotid endarterectomy

It is estimated that between 1971 and 1987 the number of carotid endarterectomies has increased from 15,000 to over 85,000 per year. Unless the procedure can be performed safely with a combined morbidity and mortality which is below the yearly risk of stroke (5%) for patients with symptomatic carotid artery disease, one should reconsider this operation as a therapeutic option. We review our experience with 891 carotid endarterectomies performed between January 1979 and June 1987. There were 579 (65%) men and 312 (35%) women of ages from 34 to 82 (median 65); risk factors included diabetes mellitus 213 (14%), hypertension 603 (68%), and smoking 630 (70%). Clinical presentation consisted of transient ischemic attacks 506 (57%), cerebral infarction with minimal neurological residual 252 (28%), stroke in evolution 3 (0.3%) and, asymptomatic stenosis 130 (15%). All patients were operated on under endotracheal anesthesia with transoperative monitoring of intra-arterial pressure, central venous pressure and arterial blood gases. Thiopental (3-5 mg/kg) and lidocaine (1 mg/kg) were given for induction and at 15 minute intervals during carotid cross-clamping. Intraluminal shunts were used in 13 (2%). A conventional (open) endarterectomy was performed in 561 (63%) and a limited endarterectomy (closed) in 330 (37%). Complications included 11 (1%) deaths, 26 (3%) developed a major neurological deficit that persisted, 30 (3%) had perioperative TIA's which resolved completely. Of the patients with preoperative neurological deficits, 33 (4%) recovered. Therefore, at one month after surgery, 854 (96%) were either as well or better than preoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid angiography in patients with lacunar infarction. A prospective study

We prospectively studied the results of carotid angiography in 45 patients with transient or nondisabling neurologic deficits caused by lacunar infarction in the internal capsule or corona radiata and demonstrated by computed tomography. An ipsilateral stenosis at the bifurcation of the internal carotid artery was found in 14 patients (31%, 95% confidence limits 18-47%), seven of whom also had stenosis of the contralateral internal carotid artery. In previous studies an average of 65% of patients with transient hemispheric deficit had internal carotid artery stenosis or occlusion. Hypertension and hypertensive retinal vasculopathy assessed by fundus photographs were found in most patients, but not significantly more often in the patients without internal carotid artery stenosis. Our findings support the notion that small vessel disease rather than emboli from the carotid bifurcation is the most common cause of lacunar infarction.

The association of central retinal artery occlusion and extracranial carotid artery disease

To determine the incidence of associated carotid artery disease and the effect of carotid endarterectomy on subsequent neurologic sequelae, a retrospective study of 66 patients with central retinal artery occlusion (CRAO) was undertaken. Ipsilateral extracranial carotid artery disease was present in 23 of 33 patients (70%) who had carotid arteriography. Sixteen patients had carotid endarterectomy following their CRAO (Group I) and 50 did not (Group II). Seven of the 40 patients available for follow-up in Group II had a subsequent stroke (mean follow-up: 54 months). Of the seven Group II patients shown to have associated carotid disease (Group IIs), three (43%) had a subsequent stroke during follow-up (mean: 28.3 months) compared to zero in Group I (p = 0.033; mean follow-up: 18.7 months). Because of the strong association between CRAO and ipsilateral carotid artery disease and because of the significantly higher incidence of subsequent ipsilateral stroke in CRAO patients with carotid disease who did not undergo endarterectomy, thorough evaluation of the carotid arteries followed by carotid endarterectomy, if indicated, is warranted in CRAO patients who have no other obvious etiology for the occlusion.

One year follow-up of patients clinically preselected for excessive risk of stroke

From a consecutive series of 812 patients at risk of stroke we selected 100 who seemed to be at high risk (excessive stroke risk--ESR) on the following clinical criteria: either multiple reversible ischemic attacks in one carotid territory or multiple (or bilateral) severe stenotic carotid lesions. The patients of the first subgroup received medical therapy and those of the second were referred for surgery. The 100 patients were followed up for 12 months, during which 29 patients had cerebral ischemic events: 17 having stroke and 12 TIA. This study suggests that it is possible to identify beforehand subgroups of ESR patients, thereby facilitating the selection of patients for brain protection and avoiding huge trials of unselected cerebrovascular patients.

Predictive value of resting electrocardiograms for 12-year incidence of stroke in the Honolulu Heart Program

The importance of electrocardiographic (ECG) abnormalities at baseline examination for subsequent risk of stroke was analyzed in a 12-year follow-up of 7,560 men in the Honolulu Heart Program, aged 45-68 years, who were free of coronary heart disease and stroke at baseline. Age-adjusted univariate analysis showed that men with major ST depression, left ventricular strain, left ventricular hypertrophy, major T wave inversion, and overall major ECG abnormalities had considerably higher (2.5-5.4 times) incidence rates of both thromboembolic and hemorrhagic stroke than those with normal baseline ECG. When blood pressure, age, cigarette smoking, alcohol consumption, fat intake, serum glucose concentration, serum uric acid concentration, years of education, and years lived in Japan were taken into consideration through multivariate analysis, the ECG abnormalities retained a significant relation with stroke. Our study demonstrates that resting ECG abnormalities are independent predictors of both thromboembolic and hemorrhagic stroke.

Failure of heparin to prevent progression in progressing ischemic infarction

Anticoagulation with heparin is frequently recommended for patients with progressing ischemic cerebral infarction, yet little data is available detailing the acute results of treatment with this agent. We report the results of continuous intravenous heparin treatment in 36 consecutive patients admitted with progressing ischemic infarction, all of whom had computed tomography scans to exclude the diagnosis of hemorrhage prior to treatment. Overall, 18 of 36 (50%) had continued neurologic worsening despite treatment. The incidence of further worsening was greater in carotid territory infarctions (14 of 19, 74%) than in either vertebrobasilar (2 of 8, 25%) or lacunar (2 of 9, 22%) infarctions (p less than 0.05, Fisher's exact test). These observations suggest that additional controlled studies of the efficacy of heparin in progressing ischemic infarction are warranted.

Vertebral artery Doppler sonography

We have examined the vertebral and subclavian arteries in 1,205 patients using directional continuous-wave (c-w) Doppler sonography, and compared the sonographic findings with the results of unilateral or bilateral retrograde brachial arteriographies in the same patients. Doppler sonography revealed 33 false positives among 909 cases with normal angiographic findings. Some types of vertebral artery (VA) lesions allowed an excellent, others a fairly good differentiation by Doppler sonography: the complete subclavian steal syndrome with constant reversal of VA flow was reliably detected (16 cases). In the incomplete steal syndrome (5 cases) sonography was superior to angiography. Two bilateral distal VA occlusions and seven basilar artery occlusions - six in the proximal third and one in the rostral third - were detected sonographically; four basilar occlusions sparing the caudal third and one case exhibiting rete mirabile anastomoses were not identified by Doppler sonography. Our acoustically defined sonographic criteria did not permit an unequivocal assignment to an anatomical variant or a vascular lesion. The sensitivity in the detection of a severe stenosis at the VA origin amounted to 16 out of 31, and to 12 of 25 in cases with a proximal VA occlusion and reconstitution of the distal VA through cervical collaterals. Our results confirm that the conventional hand-held c-w Doppler sonography cannot replace angiography in the evaluation of vertebro-basilar insufficiency. It rather serves as an aid to the decision for or against angiography, and in the follow-up of angiographically proven lesions. However, several therapeutically important lesions are readily diagnosed by sonography.

A prospective analysis of 142 carotid endarterectomies for occlusive vascular disease, 1979-1985

Carotid endarterectomy may carry a substantial risk of morbidity and mortality from major stroke, thus offsetting any statistical benefit in reduction of future stroke. Because of the disturbing ranges in the incidence of stroke morbidity and mortality reported from the several institutional series studying carotid endarterectomy, the authors undertook a prospective review of 142 consecutive carotid endarterectomies performed for symptomatic atherosclerotic occlusive vascular disease on the neurosurgical service. The University of Alabama Hospital. Preoperative risk assessment was performed in each case according to the Mayo Clinic classification system. The overall mortality rate was 1.4% and the major stroke morbidity rate was 0.7%, for a combined major morbidity and mortality rate of 2.1%. The incidence of minor neurological morbidity was 1.4%. There was no morbidity or mortality in the Grade I and II (low-risk) patient groups. This low combined major morbidity and mortality rate of 2.1% for carotid endarterectomy causes the surgical stroke-free survival curve to intersect the medical stroke-free survival curve at an earlier point in time, and thus demonstrates the greater reduction in risk of stroke which accrues over time for the surgically treated patient.

Transient cerebral ischemic attacks in a Japanese community, Hisayama, Japan

During a 20-year follow-up of 1,621 men and women aged 40 and over in Hisayama, Japan, 18 were found to have suffered transient cerebral ischemic attacks (TIAs) determined by clinical symptoms based on criteria proposed by the US Joint Committee for Stroke Facilities. The average annual incidence rate for the first TIA was 0.56 per 1,000 residents. Age and high blood pressure were strong determinants of TIAs for men. Nine of the 18 cases with TIAs (50%) subsequently developed cerebral infarction, an incidence significantly higher than that in the 1,603 subjects without TIAs (10.9%). Lacunar infarcts were most commonly found on pathologic examination of patients with TIAs who had had a subsequent stroke.

Overview on atherosclerotic systolic hypertension

Hypertension in older atherosclerotic patients is characterised by a disproportionate elevation of systolic and pulse pressure contrasting with a subnormal diastolic level. Increased systolic pressure is strongly related to the excess of cerebrovascular complications and congestive heart failure observed in these patients. The physiopathological pattern is marked by a strong reduction in compliance of large arteries directly responsible for the predominant high systolic pressure because of the impairment of the buffering function of the arteries on the cardiac pulse wave. Clinical management is directed to the elevation of athero-arteriosclerotic changes of large arteries by means of appropriate non-invasive ultrasonic techniques and specific lowering in systolic pressure. Antihypertensive treatment must specifically decrease systolic pressure without superimposing adverse effects on the generalized and focalized atherosclerotic process. In this respect, new pharmacological agents capable of direct actions on large arteries might be suitable.

Hemispheric TIA and amaurosis fugax: what is their relation to stenotic lesions of internal carotid artery?

We evaluated the correlation of clinical and echo-Doppler findings from the internal carotid artery (ICA) in 17 patients with amaurosis fugax (AF) and in 68 patients with hemispheric TIA (H-TIA). In the study population as a whole, moderate stenoses (20%-49% diameter reduction) were the most prevalent finding in the symptomatic ICA, being detectable in 51.6% of cases. Total occlusions were found in an unexpectedly high percentage (7.5%). Asymptomatic ICAs, that were contralateral to the symptoms, showed the same degree of atherosclerotic involvement as the symptomatic ICAs. When we compared AF with H-TIA, we found a significantly higher prevalence of severe hemodynamically significant stenoses in the former (52.6% vs. 18.8%, chi-square test 10.85, P less than 0.05). Thus, we conclude that in the vast majority of patients with transient neurological symptoms a bilateral ICA involvement is to be expected. The side on which the symptoms occur does not indicate which ICA is more severely stenotic except in AF, where a severe involvement of the ipsilateral ICA is most likely.

Italian multicenter study on reversible cerebral ischemic attacks: VI--Prognostic factors and follow-up results

A total of 462 patients (mean age 52 years) affected by reversible focal ischemic attacks (RIAs) were followed prospectively in 8 neurologic institutions in Italy for 4 years. All cases were evaluated with a cerebral angiography and 21% of angiograms were normal. At the end of the follow-up period the cumulated probability for death, stroke, cardiac event and new RIA was respectively 7%, 8%, 3% and 36%. The predictive value of the baseline characteristics of this series was evaluated by a multifactorial analysis which showed that RIA and stroke (specific cerebrovascular risk) were more likely to develop in patients with a history of more than one RIA and in those in whom multiple vascular territories were involved. Moreover, previous myocardial infarction, intermittent claudication, angina pectoris, time elapsed since the first attack, and duration and severity of the attack itself were independently associated with general cardiovascular risk (death, stroke and myocardial infarction). We conclude that predictive factors, and thus also pathogenetic mechanisms, may be different for general cardiovascular risk and specific cerebrovascular risk in RIA patients.

Microsurgical endarterectomy under barbiturate protection: a prospective study

Carotid endarterectomy has the potential to improve on the natural history of untreated carotid artery disease with respect to subsequent infarction in symptomatic patients with causative angiographic lesions. This benefit of a reduced risk of stroke can be realized only if the perioperative morbidity and mortality rates are kept low. An approach to symptomatic carotid artery bifurcation disease is outlined, with a defined protocol of microsurgical endarterectomy utilizing barbiturate protection during the period of potential focal temporary cerebral ischemia. This protocol includes preoperative antiplatelet therapy, barbiturate anesthesia, the avoidance of an internal shunt, the use of the operating microscope, and strict control of postoperative hypertension. A series of 200 consecutive endarterectomies performed within this protocol in 180 patients and the resultant combined permanent morbidity and mortality rate of 1.5% are reported.