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The heart is an important site for thrombus formation and cardioembolic events are a frequent cause of stroke. Many cardiac factors may contribute to the risk of cardioembolism. Clinicians must be mindful that those cardiac disorders most likely to cause cardioembolic events include atrial fibrillation, left ventricular dysfunction, valvular heart disease, and structural cardiac abnormalities. The presence of many such conditions mandates the use of specific preventive therapies. Improved diagnostic methods, particularly TEE, now allow more accurate identification and follow-up of potential cardiac sources. Embolus detection monitoring has the potential to allow in vivo identification of embolic events and offers the possibility of objective longitudinal assessment of the impact of therapy. Intravascular ultrasound is an invasive test, but it may eventually allow the most accurate evaluation of the cardiac chambers. New therapies, and new combinations of currently available compounds, may ultimately offer more specific and efficacious alternatives to prevent formation of cardiac thrombus and subsequent cardioembolism. The importance of the heart-brain relationship in stroke has finally been appreciated. Improved understanding of this complex interrelationship will have great impact on clinical practice in the future.

The development of new management strategies for acute stroke demands better understanding of the ischemic mechanism, cerebrovascular anatomy, and cerebral hemodynamics for individual patients. The use of carotid duplex sonography, transcranial Doppler sonography, and echocardiography allows evaluation of the key areas of interest in a prompt, safe, accurate, and cost effective manner.Knowledge of these methods is essential for neurologist caring for patients with stroke.

To quantify the volume flow rate- (VFR-) effects of internal carotid disease on the common carotid artery both ipsi- and contralaterally for various degrees of stenosis.A non-invasive ultrasonic time domain processing (M-mode) was used. This proved to be reproducible in vivo and accurate in vitro. 109 patients (mean age 66.7 yrs.) having at least 50% stenosis of the internal carotid artery or a cerebral ischaemia were studied. The haemodynamic effect of the stenosis on the entire anterior brain circulation supplied by the carotid artery was assessed. Stenoses were graded in 4 groups.Significant VFR reduction occurred ipsilaterally in high grade (75-94%) stenosis and occlusion of the internal carotid artery, but not with moderate (50-74%) stenosis (p0.05). Ipsilaterally to stenoses there was a decrease in VFR, which was more marked in higher than in lower grade stenoses. Contralaterally there was an increase in VFR. These groups differed in a statistically significant way (p0.05).This ultrasonic VFR method demonstrates the flow effect of carotid stenoses both ipsi- and contralaterally and adds to the understanding of the haemodynamics in individual patients.

Several mechanisms contribute to the increased stroke rate of patients with atrial fibrillation (AF). We assessed the frequency of carotid artery stenosis in patients with AF and its relationship to stroke during aspirin or warfarin therapy.Carotid ultrasonography was done in 676 patients with AF enrolled in the Stroke Prevention in Atrial Fibrillation Study to detect cervical carotid stenosis of 50% or more of the luminal diameter. The presence of carotid stenosis was correlated with patient features and subsequent stroke during a mean of 2.6 years of follow-up.In patients with AF who were older than 70 years, the frequency of carotid stenosis was 12% in men and 11% in women. Carotid stenosis was independently associated with systolic hypertension (relative risk, 2.4; P = .002), diabetes (relative risk, 1.8; P = .04), and tobacco use (relative risk, 1.8; P = .02). Carotid stenosis did not add significantly to prediction of stroke when analyzed with other clinical risk factors for stroke in patients with AF (relative risk, 1.3; 95% confidence interval, 0.5 to 3.6; P = .55).Carotid artery stenosis of 50% or more occurs in about 12% of elderly patients with AF, reflecting the substantial prevalence of hypertension and diabetes in these patients. Carotid stenosis was not usefully predictive of stroke in patients with AF who were given aspirin or warfarin. Routine ultrasonography to detect carotid stenosis does not appear warranted in patients with AF without previous symptoms of brain ischemia.

The use of transcranial Doppler sonography (TCD) for the evaluation of patients with ischemic cerebrovascular disease remains controversial. This study was organized to gather preliminary data regarding the sensitivity and specificity of TCD when compared to cerebral angiography in detecting stenosing lesions and collateral flow patterns of the anterior cerebral circulation. Forty-two patients from six medical centers were prospectively enrolled. Each received cerebral angiography and TCD testing within 24 hours of each other. Based on TCD criteria established a priori, the results were first analyzed by a blinded investigator and then by computer. Computerized analyses were then repeated with modified criteria. Collateral flow through the anterior communicating and ophthalmic arteries was detected with sensitivities of 62% and 100%, and specificities of 98% and 92%, respectively. Internal carotid artery proximal and distal severe ( greater than 70%) stenoses were detected with sensitivities of 79% and 100% and specificities of 88% and 97%. Middle and anterior cerebral artery stenoses and middle cerebral artery occlusion were detected with specificities exceeding 98%; however, the data were insufficient to determine sensitivity. Computerized analyses did not permit improvement of sensitivity and specificity of the baseline criteria. The selected TCD criteria are highly specific in detecting intracranial stenoses and collateral flow patterns of the anterior circulation. The criteria have limited but acceptable sensitivity and specificity in detecting internal carotid artery origin severe stenoses, and are highly sensitive in detecting ophthalmic artery retrograde flow. A study with a larger sample is necessary to provide definitive guidelines for diagnosis.

A project to pursue standardization of the performance and interpretation of transcranial Doppler studies was designed. Phase I consisted of a national survey of the current practice of transcranial Doppler in the United States. From 200 ultrasound laboratories surveyed about the use of transcranial Doppler, 60 completed questionnaires were returned. The results show that further standardization of transcranial Doppler performance and interpretation is necessary, and provide the foundation for phases II and III of the project.

Echocardiography is an established technology encompassing an increasingly wide variety of clinical situations including cardioembolism and the detection of CAD in patients with cerebral ischemia and in patients undergoing neurovascular surgery. Echocardiography will continue to occupy a pivotal role in clinical management and research in the area of brain heart interaction.

Vascular headache is an extremely common disorder. Current evidence points to an underlying neurogenic etiology, and the associated vascular changes are believed to be epiphenomena. Vascular headache tends to begin at a young age, is more common in women, and is frequently associated with a positive family history. Characteristics of the headache frequently suggest the diagnosis. The history and physical examination are keys to the diagnostic evaluation. A computed tomography scan when indicated is the single test with the highest yield of information. Non-narcotic analgesics, ergot compounds, and metoclopramide are the most commonly used agents for acute attacks. Beta blockers and amitriptyline are the most widely used prophylactic medications. Nonpharmacologic measures are occasionally of great benefit.