Transient ischaemic attacks: evaluation and management

Transient ischaemic attacks (TIAs) are temporary focal cerebral or retinal deficits that resolve within 24 hours. Attention should be given to the tempo and localisation of the clinical syndrome, as multiple and hemispheric TIAs are associated with the greatest incidence of early stroke. Evaluation of TIAs depends on the clinical symptoms, physical examination and investigations. Attention should be given to clinical evidence of generalised atherosclerotic disease, as death due to the complications of ischaemic heart disease is the commonest outcome in patients with TIA. Early attention should focus on risk factor modification, with emphasis on the treatment of hypertension and smoking cessation. Antiplatelet therapy should be instituted. Aspirin is the first-line treatment but, if not tolerated, clopidogrel is effective in preventing vascular complications. Anticoagulants are generally reserved for patients with atrial fibrillation and are associated with a significant reduction of stroke risk. The use of statins is becoming more widespread, with emerging evidence of their efficacy in reducing stroke risk. The risk of stroke is greatest in the weeks following TIA and patients should be referred for carotid duplex ultrasonography. Carotid endarterectomy for symptomatic internal carotid artery high grade stenosis virtually abolishes stroke risk in that vascular territory over subsequent years. TIAs should be regarded as an emergency requiring early diagnosis and prompt referral.     

The Natural History of Asymptomatic Extracranial Arterial Disease

The natural history of a group of 76 patients without neurologicalsymptoms, but with untreated extracranial arterial disease demonstratedby angiography 10 years ago, was studied. During this period46 patients died, and coronary artery disease was the most commoncause of death (n = 25). Six patients suffered a lethal stroke,five patients had a stroke before they died from other causesand five of the six surviving patients, who became symptomaticdeveloped TIAs, followed by a stroke in two cases, leaving onlyone who suffered a sudden stroke without premonitory warningsymptoms. Although the overall cumulative stroke rate (18 percent) was three times higher than normal, the cerebrovascularterritories affected corresponded only twice with the originalextracranial carotid lesion. Therefore, early carotid endarterectomyis inadvisable for the majority of asymptomatic patients andrepetitive non-invasive prospective study of these patientsis favoured for selection of more appropriate timing for individualtreatment.     

Transient Ischemic Attacks (TIA): Current Issues in Diagnosis and Management

Transient ischemic attacks (TIAs) affect more than 500,000 Americans each year. Stroke risk approximates 4% to 8% within 1 month and increases to 12% to 13% at one year. This has led to stroke being one of the leading causes of death and disability. TIAs are focal neurologic events that are temporary in nature and warn of potential stroke. Most TIAs resolve within 24 hours. Hypertension, smoking, heart disease, and diabetes are the major risk factors for stroke. A comprehensive history of symptoms can help identify carotid vs. vertebrobasilar disease. Timely evaluation of TIAs should be performed according to recent guidelines set forth by the American Heart Association. Aspirin continues to be the gold standard for stroke prevention, conferring a 48% risk reduction in stroke or death. The use of ticlopidine has been recommended as a second-line agent in patients with aspirin intolerance. Surgical intervention (carotid endarterectomy) is indicated in symptomatic patients with high grade stenosis of 70% or greater. For patients with less significant stenosis, inconclusive data exists regarding the benefit of medical vs. surgical treatment. Patient education should address identification of symptoms, the need for prompt medical attention, and risk factor modification. A collaborative plan between clinician and client will facilitate early intervention ultimately leading to preservation of function and prevention of the catastrophic sequelae of stroke.     

The natural history of asymptomatic extracranial arterial disease

The natural history of a group of 76 patients without neurological symptoms, but with untreated extracranial arterial disease demonstrated by angiography 10 years ago, was studied. During this period 46 patients died, and coronary artery disease was the most common cause of death (n = 25). Six patients suffered a lethal stroke, five patients had a stroke before they died from other causes and five of the six surviving patients, who became symptomatic developed TIAs, followed by a stroke in two cases, leaving only one who suffered a sudden stroke without premonitory warning symptoms. Although the overall cumulative stroke rate (18 per cent) was three times higher than normal, the cerebrovascular territories affected corresponded only twice with the original extracranial carotid lesion. Therefore, early carotid endarterectomy is inadvisable for the majority of asymptomatic patients and repetitive non-invasive prospective study of these patients is favoured for selection of more appropriate timing for individual treatment.     

Total occlusion of the common carotid artery: a modified classification and its relation to clinical status

To investigate the hemodynamics and clinical presentation of common carotid artery occlusion (CCAO), we reviewed 6,415 patients with suspected carotid artery disease in whom a color Duplex imaging (CDI) examination was performed. According to distal vessel patency, the following CDI classification of CCAO was adopted: type I (patent both distal vessels); type II (isolated patency of external carotid artery); type III (isolated patency of internal carotid artery); and type IV (both distal vessels occluded). Thirty-five (0.5%) cases met the CDI criteria for CCAO. Twenty-nine of those (83%) had at least one patent distal vessel. Ten patients (29%) presented with stroke, 20 (57%) with transient ischemic attacks (TIAs) and five (14%) were asymptomatic. The incidence of stroke was higher in type IV (50%) vs. type II (30%) and in type II vs. type I (10%) lesions. Similarly, TIAs presented more often in type II (67%) and IV (50%) vs. in type I (40%) lesions (p = 0.002). Retrograde flow in the ophthalmic artery and concomitant severe contralateral carotid artery stenosis were more often related with type II and IV lesions (p = 0.02 and 0.04, respectively). CCAO is usually accompanied by patent distal vessel(s). The proposed CCAO classification correlates well with the patients' clinical status and may help to better clarify the outcome of this rare entity. Among the main arteries of the developed collateral circulation, only the flow direction in the ophthalmic artery may be of clinical value.     

Carotid endarterectomy. Controversies and recommendations

Carotid endarterectomy is a comparatively safe procedure for prevention of stroke in carefully selected patients with carotid stenosis. Generally, it is indicated in patients with hemispheric symptoms of transient ischemic attacks (TIAs), but it is more controversial in patients with non-hemispheric TIA symptoms or no symptoms. Emergency endarterectomy in patients with acute TIA symptoms is considered dangerous. Results of a series of 120 endarterectomies performed at Straub Clinic, Honolulu, confirm the benefits of elective endarterectomy when a meticulous operative technique is followed and intraoperative angiography and repair of defects are done. Prophylactic endarterectomy should not be performed unless a very low incidence (less than or equal to 3%) of combined major morbidity and mortality can be achieved.     

Carotid surgery in stroke prevention

Extracranial carotid disease accounts for up to 50 percent of strokes. Transient ischemic attacks are associated with a 30 to 35 percent risk of stroke within five years of the initial episode. Carotid endarterectomy is a safe and effective way of reducing the risk of stroke in patients with TIAs. It is also helpful in patients with amaurosis fugax, and may benefit selected patients with acute stroke or those with asymptomatic but hemodynamically significant stenosis.     

Duplex sonography in patients with hemispheric symptoms

Many patients with hemispheric neurologic symptoms do not have operative stenoses of the extracranial carotid arteries. In order to assess the frequency of such atherosclerotic lesions, 154 patients with documented hemispheric events underwent duplex Doppler examinations of the extracranial carotid bifurcation to assess if operative stenosis (70% to 80% stenosis) was present. Seventy-two patients with transient ischemic attacks (TIA), 62 patients with cerebrovascular accidents (CVA), and 20 patients with amaurosis fugax (AF) were studied. Sixty-nine percent of patients with TIAs demonstrated a less than 50% stenosis, 52% of patients with CVAs demonstrated a less than 50% stenosis, and 65% of patients with AF demonstrated a less than 50% stenosis on duplex Doppler examination. Intra-arterial digital subtraction angiography (IADSA) was performed in 35 of 154 patients. In all of these 35 cases, ultrasound and angiographic studies agreed with respect to whether or not a greater than 50% stenosis was present. Our findings support the use of duplex Doppler sonography as a triage procedure in patients with hemispheric events in order to determine those patients who have significant carotid stenoses and who may be potential operative candidates.     

头颈部CT血管造影对急性缺血性脑卒中早期的诊断价值

目的:分析应用头颈部非创伤性血管成像技术(简称CT血管造影)(CT angiography,CTA)实施颈动脉狭窄诊断对于急性缺血性脑卒早期诊断的应用价值.方法:选取2020年5月—2021年5月宁津县人民医院收治的50例疑似颈动脉狭窄急性缺血性脑卒中患者,对入组患者均实施头颈部CTA扫描及颈部血管彩超,对比数字减影血...     

Complications of carotid endarterectomy: the influence of case load

We reviewed the records of 508 consecutive carotid endarterectomies done by 19 surgeons during a five-year period in one medical center to evaluate postoperative complications (stroke and death). Each of 16 surgeons did 32 operations or fewer, with case loads ranging from one to 32. Three surgeons did 70, 98, and 172 respectively. The incidence of stroke among patients of the 16 surgeons combined who did 32 cases or fewer in five years (fewer than ten cases per year) was 7%, with a combined stroke and death rate of 8%; in contrast, patients of the combined surgeons who did more than 32 operations in five years (more than ten cases per year) had a stroke rate of 3%, with a combined stroke and death rate of 3%. When the carotid disease was examined separately, it was apparent that the adverse event rate among patients with asymptomatic or nonhemispheric disease accounted for the difference. Patients of surgeons with fewer cases had 18% adverse events, whereas those of more experienced surgeons had 2% adverse events. The adverse events were similar for both groups in patients with focal transient ischemic attacks or stroke. Seven of the 16 surgeons who did fewer than 32 cases had no patients who had stroke, despite the few carotid endarterectomies they had done. Thus, the stroke rate was somewhat lower in the hands of those surgeons who did endarterectomy more often, but the number of carotid endarterectomies done by a surgeon is not the only factor to decrease the stroke rate. Proper selection of patients and attention to risk factors and technique are essential.     

Anatomical variations of the carotid-vertebral arteries: "double-vessel" sign on Doppler ultrasonography

We describe the "double-vessel" sign and its relevance for the diagnosis of carotid and vertebral arterial anatomical variations in a series of four patients with stroke. In these four patients, two arteries could be seen at the expected location of the common carotid artery (CCA), leading to the diagnosis of anatomical variations including separate origin of internal and external carotid artery from the aortic arch on the left side and from the brachiocephalic trunk and the subclavian artery on the right side, early bifurcation of the CCA on both sides, and an aberrant course of the vertebral artery on the left side. The presence of two arteries at the expected location of the CCA should raise the suspicion of carotid or vertebral arterial variations.     

Ultrasonographic prediction of patients' outcome in hyperacute ischemic stroke.

OBJECTIVE: We examined whether carotid ultrasonographic (US) findings in hyperacute ischemic stroke are useful to predict patients' outcome. METHODS: We studied 73 consecutive patients with carotid stroke using both computed tomography (CT) and duplex carotid ultrasonography within 6 h of stroke onset. We evaluated early CT findings defined as obscuration of the lentiform nucleus, loss of the insular ribbon and/or cortical effacement, and US findings indicating internal carotid artery (ICA) or middle cerebral artery trunk occlusion. The National Institute of Health Stroke Scale (NIHSS) at admission and modified Rankin scale on day 30 were assessed. RESULTS: According to multiple logistic regression analysis, positive US findings (P = 0.0045, odds ratio, 11.1) provided the best predictor of modified Rankin scale score > or =3 compared with a baseline NIHSS> or =16 (P = 0.036, odds ratio, 7.9) and early CT findings (P = 0.18). CONCLUSION: US findings of hyperacute stroke may provide a better predictor of patients' outcome.     

Executive function deficits in acute stroke

OBJECTIVES: To establish the frequency of executive dysfunction during acute hospitalization for stroke and to examine the relationship of that dysfunction to stroke severity and premorbid characteristics. DESIGN: Inception cohort study. SETTING: Inpatient wards at a Veterans Affairs hospital. PARTICIPANTS: Consecutive sample of inpatients with radiologically or neurologically confirmed stroke. Final sample included 47 patients screened for aphasia and capable of neuropsychologic testing. Two nonstroke inpatient control samples (n=10 each) with either transient ischemic attack (TIA) or multiple stroke risk factors were administered the same research procedure and tests. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Composite cognitive impairment ratio (CIR), calculated from 8 scores indicative of executive function on 6 neuropsychologic tests by dividing number of tests completed into the number of scores falling below cutoff point, defined as 1.5 standard deviations below normative population mean. RESULTS: Stroke patients had a mean CIR of .61, compared with .48 for TIAs and .44 for stroke-risk-only. Analysis of variance revealed that CIRs of stroke-risk-only patients but not TIAs were lower than those of the stroke patients (P=.02). Impairment frequencies were at least 50% for stroke patients on most test scores. The Symbol Digit Modalities Test (75% impairment) and a design fluency measure distinguished stroke from nonstroke patients. CIR was not related to stroke severity in the stroke patient sample, but was related to estimated premorbid intelligence. CONCLUSIONS: Executive function deficits are common in stroke patients. The data suggest that limitations in information processing due to these deficits may require environmental and procedural accommodations to increase rehabilitation benefit.     

The role of surgery in ischemic stroke.

Surgery in the management of stroke is useful primarily as a stroke-preventive measure for patients with extracranial carotid artery occlusive disease. Ideally, lesions that are potential sources of ischemia are removed before a fixed neurologic deficit can occur. Patients with transient ischemic attacks and no deficit or only minor neurologic deficit comprise the largest group of surgical candidates. Diagnostic angiography must be carried out before endarterectomy and should include aortic arch studies of both extracranial and intracranial carotid arteries. Placement of an intra-arterial catheter at the beginning of surgery provides the best method of monitoring arterial pressure. A postoperative angiogram allows visual confirmation of the patency of reconstructed vessels. Such confirmation is particularly important if patients have severely stenotic bilateral carotid artery disease. The surgical mortality for all patients with TIAs is between 1% and 2% in those clinics in which this type of operation is commonly done.     

Timing of carotid surgery after acute stroke

Carotid endarterectomy (CEA) has been proven to reduce the risk of stroke and death in both asymptomatic and symptomatic patients with carotid occlusive disease. Stroke is the third leading cause of death in the USA. Since up to one-third of stroke patients have a stroke secondary to carotid occlusive disease, it is important to offer CEA to this subgroup of patients that meet indications for surgery. Historically, literature has suggested that the optimal timing to perform CEA is approximately 6 weeks after an acute stroke. This was concluded owing to high perioperative morbidity and mortality if CEA was performed too early. However, data are increasingly showing that some patients do benefit from CEA earlier than 6 weeks after an acute stroke. This article discusses mid-20th Century literature and focuses on more recent 21st Century literature discussing the timing of CEA after acute stroke. Although there are data to support delayed CEA, it is reasonable to perform early CEA in select stroke patient populations. Candidates for early CEA should have complete or near resolution of symptoms, small infarcts on imaging and ipsilateral carotid stenosis.     

Timing of carotid surgery after acute stroke

Carotid endarterectomy (CEA) has been proven to reduce the risk of stroke and death in both asymptomatic and symptomatic patients with carotid occlusive disease. Stroke is the third leading cause of death in the USA. Since up to one-third of stroke patients have a stroke secondary to carotid occlusive disease, it is important to offer CEA to this subgroup of patients that meet indications for surgery. Historically, literature has suggested that the optimal timing to perform CEA is approximately 6 weeks after an acute stroke. This was concluded owing to high perioperative morbidity and mortality if CEA was performed too early. However, data are increasingly showing that some patients do benefit from CEA earlier than 6 weeks after an acute stroke. This article discusses mid-20th Century literature and focuses on more recent 21st Century literature discussing the timing of CEA after acute stroke. Although there are data to support delayed CEA, it is reasonable to perform early CEA in select stroke patient populations. Candidates for early CEA should have complete or near resolution of symptoms, small infarcts on imaging and ipsilateral carotid stenosis.     

Duplex sonographic predictors of restenosis,vascular and neurological events after carotid endarterectomy

BACKGROUND: Although excellent short- and long-term results have been achieved with surgery in extracranial internal carotid artery stenosis, recurrent stenosis continues to play an important role in post-endarterectomy. Therefore, a close follow-up of patients is warranted. The value of postoperative duplex sonographic evaluations in postoperative follow-up is highly disputed. The study evaluates duplex sonographic parameters as predictors of carotid restenosis, general vascular events and ipsilateral neurological symptoms, in order to assess the role of duplex sonography in follow-up after carotid endarterectomy. METHODS: A retrospective cohort study with a follow-up period ranging from 7 months to 7.5 years was performed in 150 patients who underwent carotid endarterectomy. Pre- and postoperative duplex sonographic and clinical data were analyzed by life-table analysis and multivariate Cox regression with respect to carotid restenosis, vascular and ipsilateral neurological events. MAIN FINDINGS: Duplex sonographic predictors of carotid restenosis include the postoperative degree of stenosis (residual stenosis > or = 30% or more: relative risk (RR) = 1.56; 1.05-2.32), pre- to postoperative reduction of stenosis (higher than 50%: RR = 0.61; 0.45-0.83), and residual plaques in the operated carotid artery (RR = 1.96; 1.31-2.93). Some of these morphological parameters such as reduction of stenosis are also predictive of vascular events (RR = 1.25; 1.01-1.56) and ipsilateral neurological events (RR = 1.52; 1.05-2.19). In 12 cases restenosis was discovered by duplex sonography and in 3 cases by evaluation of clinical symptoms. In 5 cases restenosis was treated by repeat surgery. Contralaterally, progressive or newly developed carotid stenoses were observed in 17 cases, and only 5 were discovered on the basis of clinical symptoms. Fourteen contralateral stenoses required surgery. Overall, 12 patients underwent treatment for stroke prevention on the basis of duplex follow-up findings (8% of the study population). CONCLUSIONS: Postoperative duplex sonography allows for the identification of patients at risk for carotid restenosis as well as those at risk for other vascular events. As expected, regular examinations permit early detection of restenosis requiring surgical treatment. However, a large number of contralateral stenoses requiring surgical treatment were detected by routine duplex sonographic examinations. The timing of follow-up intervals may be oriented towards the perioperative outcome of duplex sonography.     

颈动脉内膜剥脱术后即期脑中风的病因、影响因素及治疗（摘要）

对２９１例颈动脉内膜剥脱术后患者进行随访研究，１例术后即期死亡；２２例（６．３％）在术后发生脑中风，１７例为中度中风，５例为严重中风，即期中风的病因包括：１４例手术部位颈动脉血栓形成（１４／２２，６４％），４例术中或术后即期脑栓塞，２例阻断颈动脉所致脑缺血，１例脑出血，１例原因不明，此外讨论了术后中风的危险因素和处理方法。     

Prospective study of the effectiveness and durability of carotid endarterectomy

In a series of 252 consecutive patients who underwent 282 carotid endarterectomies, we conducted clinical and angiographic follow-up for 2 to 6 years (mean, 3.2 years). Digital subtraction angiography (DSA) was done postoperatively in 95% of cases. Clinical follow-up was achieved in 97% of cases, and DSA follow-up was obtained in 66% of cases. The overall group had a 1% operative minor morbidity (three cases of minimal new neurologic deficit), no major morbidity, and a 0.7% mortality (one death from stroke and one from myocardial infarction). Complications correlated well with the patient's preoperative risk category. During follow-up, 10 minor strokes, only 1 of which was attributable to the reconstructed artery, and 10 transient ischemic attacks, 3 of which were presumably related to recurrent stenosis, occurred. Asymptomatic mild to moderate restenosis of the internal carotid or common carotid artery was identified in 10% of follow-up DSAs and severe stenosis or occlusion in 3%. Stenosis in the opposite common carotid or internal carotid artery progressed in 48 cases (26% of follow-up DSAs and ultrasound studies), and 10 of these became symptomatic. An actuarial analysis of patients who had endarterectomy indicated that the cumulative probability of ipsilateral stroke was 1.5% at 1 month and 2% at 5 years. The cumulative probability of ipsilateral stroke, transient ischemic attack, or reversible ischemic neurologic deficit was 4% at 1 month and 8% at 5 years or less than 1% per year after the first month, with censoring at the time of the second surgical procedure.