Echocardiographic evaluation of young adults with nonhemorrhagic cerebral infarction

Modern management of a patent foramen ovale

A patent foramen ovale (PFO) has been associated with medical conditions such as cryptogenic stroke, migraine with aura, and decompression illness. Whether closure of the PFO has clinical benefit has been suggested from registry studies, but not yet confirmed in multiple randomized trials. Methods of diagnosis of a PFO and a summary of the current evidence for treatment is presented and discussed as a guide to patient-centred decision-making.

Transesophageal echocardiography discloses unexpected cardiac sources of embolus in stroke patients aged more than 45 years

Cerebral embolism from cardiac source is an important cause of stroke, specially in patients younger than 45 years old. OBJECTIVE: To describe the transesophageal echocardiography (TEE) findings in young and non-young stroke patients without any prior evidence of cardiac source for cerebral embolism. METHOD: Transversal study: 523 patients (267 men and 256 women) with ischemic stroke, without any evidence of cardiac abnormality, underwent to TEE. RESULTS: Ten percent were aged 45 years; or less. Left ventricle hypertrophy, left atrial enlargement, spontaneous contrast in aorta, interatrial septum aneurysm, mitral and aortic valve calcification, aortic valve regurgitation, and atherosclerotic plaques in aorta were significantly more frequent in patients aged more than 45 years; 2.8% of non-young patients had thrombus in left heart. CONCLUSION: TEE is widely used to diagnose cardiac source of cerebral embolism in young patients, but it seems to be as useful for older ones, in whom cerebral embolism risk is underestimated; atherogenic and cardioembolic causes may actually coexist, and both should be treated.

Echocardiography in stroke and the prescription of new anticoagulation and cardiac medications: A pilot project

Previous research on echocardiography in patients with acute stroke has focused on identifying possible cardioembolic etiologies of the stroke, but physicians might also obtain echocardiography to guide the management of heart disease in stroke patients. The objectives of this study were to determine how frequently echocardiography is used in acute ischemic stroke patients, and to evaluate if receiving echocardiography is associated with new prescriptions for anticoagulant or cardiac medications. This secondary data analysis of a previous cohort study included medical records of acute ischemic stroke patients admitted to 1 of 10 acute-care hospitals in Connecticut from 1996 to 1998. A total of 58 of 119 (49%) acute ischemic stroke patients received echocardiography. Among these 58 patients, 43 (74%) received either a new prescription for anticoagulation or a new cardiac medication prescription (10 of 58 [17%] new anticoagulation only, 22 of 58 [38%] new cardiac medication only, and 11 of 58 [19%] both). New anticoagulant medications were prescribed more often in patients receiving echocardiography (21 of 58; 36%), than in patients not receiving echocardiography (10 of 61; 16%) (P = .014). In addition, new cardiac medications were prescribed more often in patients receiving echocardiography (34 of 58; 59%), than in patients not receiving echocardiography (24 of 61; 39%) (P = .035). Echocardiography is commonly obtained in patients with acute stroke, and its use is associated with both the prescription of new anticoagulation and new cardiac medications. Although previous research about the use of echocardiography in acute stroke has focused on its role in identifying stroke etiologies, future research should include an assessment of it use in treating concomitant heart disease.

[Cerebrovascular diseases in patients aged 15 to 40 years: neuropathological findings in 47 cases]

Cerebrovascular diseases in patients between 15 and 40 years old are not a frequent subject in Latin-American literature, especially when focusing on neuropathology. We analyzed 47 brains from necropsies performed from 1987 to 1997 and selected on a basis of age and the presence of vascular pathology. From the 47 analyzed brains, 26 belonged to females (55.3%). When distributed among age groups, 12.8% (n=6) affected patients from 15 to 20 yo, 51,1% (n=24) from 21 to 30 yo, 36,2% (n=17) from 31 to 40 yo. The underlying diseases were: cardiac and haemathologic (19.2%), pregnancy complications (12.76%), infections, diseases of blood vessels and neurological (10.1% each) amongst others. The neuropathological abnormalities included cerebral and/or cerebellar herniation (16%), cerebral edema (13.8%), subarachnoid hemorrhage (10%), recent cerebral infarction (9%), intraparenchymatous hemorrhage (8.14%), hypoxic-ischemic encephalopathy (3%) and other events such as Sneddon syndrome and Lupus vasculitis. These findings express that the cerebrovascular phenomena in this age group are unique and closely related with the underlying disease.

Transesophageal echocardiography for the evaluation and management of patients with cerebral ischemia

To prevent recurrent strokes and transient ischemic attacks, considerable attention is devoted to investigating the etiology of acute cerebral ischemia in the large subpopulation of patients without an easily identifiable cause. In general, transthoracic echocardiography is an insensitive tool for the evaluation of patients with cerebral ischemia, unless clinical signs and/or symptoms of cardiac disease are present. Transesophageal echocardiography (TEE), because of its increased sensitivity for aortic arch atheromata, atrial septal pathology, left atrial thrombi, and valvular abnormalities, is the preferred cardiac imaging modality, especially in young patients, older patients with hypertension or systemic atherosclerosis, and patients with prosthetic heart valves. This paper reviews the prognostic and therapeutic impact of TEE in patients with cerebral ischemia, specifically focusing on the ability of information obtained by this technique to alter patient management and improve risk stratification.

Role of echocardiography in systemic arterial embolism. A review with recommendations

The ability of echocardiography to diagnose sources of embolism and the role of the examination in the prediction of thromboembolism are reviewed. In addition, the yield of transthoracic (TTE) and transoesophageal echocardiography (TEE) is analysed in patients with suspected embolism and guidelines are proposed for performing echocardiography in this setting. In general, echocardiography is reliable for diagnosing sources of embolism and this applies in particular to TEE in the case of atrial, valvular, and aortic abnormalities. However, the method is useful for predicting embolism in a few cases only. There is a substantial risk in the event of mobile or protruding thrombi, but screening for these and other markers of thromboembolism seems to be unproductive in most groups of risk patients. Yet, in the presence of atrial fibrillation, echocardiography may be helpful in defining patients with an otherwise normal heart and low risk of embolism--and in defining the relatively rare patient with a clinically low-risk profile but moderate-to-severe left ventricular systolic dysfunction and a high risk of embolism. TEE-guided conversion of atrial fibrillation without weeks of preceding anticoagulation may prove useful, after further investigation. The risk of embolism in relation to the size and mobility of valvular vegetations has remained controversial. In patients with suspected recent embolism, TTE results in less than 5% new therapeutic consequences. In those with a normal TTE, the yield of TEE seems to be equally low. We therefore recommend a selective strategy: TTE and TEE can be omitted when a cardiac source of embolism appears from the clinical setting and in most patients with an obvious predisposition to cerebrovascular disease. However, in the latter cases TTE should be performed if indicated by the clinical situation, e.g. in the presence of fever and murmur. TTE is also recommended when there are no obvious markers of primary vascular disease. To preclude very rare sources of embolism (e.g. atrial thrombi despite sinus rhythm), supplementary TEE is recommended in younger patients in whom primary vascular disease is very unlikely. The diagnosis by TEE of common conditions such as atrial septal aneurysms and patent foramen ovale cannot, however, be taken as proof of the mechanism of a systemic arterial occlusive event; thus it is difficult to change therapy on the basis of such diagnoses.

Noninfective mitral valve vegetations identified by transesophageal echocardiography as a cause of stroke

BACKGROUND

Transesophageal echocardiography (TEE) is a useful procedure to evaluate selected stroke patients for cardiac sources of embolism. To date, noninfective valvular vegetations have not been described in large studies using transesophageal echocardiography to detect cardiac sources of embolism. We sought to investigate the frequency of noninfective valvular vegetations in patients with unexplained stroke referred for TEE and to determine the relationship of these vegetations to unrecognized thrombophilic disorders.

METHODS

We evaluated 641 consecutive patients referred for TEE as a result of unexplained stroke or transient ischemic attack for the presence of valvular vegetations. Of those with vegetations identified, serial blood cultures were obtained to evaluate for an infectious etiology. Patients also had serum testing for thrombophilic disorders and selected patients underwent cerebral angiography.

RESULTS

Thirteen patients (2%) who underwent TEE evaluation for unexplained stroke or transient ischemic attack were found to have noninfective valvular vegetations, all involving the mitral valve; none were identified by transthoracic echocardiography. Antiphospholipid antibodies were identified in 8 of these 13 patients (62%) and a protein C deficiency in 1 patient (8%).

CONCLUSIONS

Noninfective valvular vegetations are a potential cardiac source of embolism in patients with unexplained stroke that can be better identified using transesophageal echocardiography. A large percentage of these individuals have a previously unrecognized thrombophilic disorder.

Causes of ischaemic stroke in the young

The causes of ischaemic stroke in young adults are many and diverse. Such patients usually require more extensive investigations in order to find an underlying cause than more elderly patients. It is important that a comprehensive search is made since many of the underlying disorders are treatable. Principal causes are extracranial arterial dissection, cardioembolism, premature atherosclerosis, haematological and immunological disorders and migraine. Drug abuse is becoming increasingly important but the risk of stroke in pregnancy remains unclear. Isolated angiitis of the central nervous system, heritable disorders of connective tissue and other genetically determined disorders (mitochondrial cytopathies, CA-DASIL) account for a small proportion of ischaemic strokes in the young. Management is probably best undertaken by a physician with a specialist interest and, if full investigation fails to elucidate a definite cause, the risk of future stoke is low.

The role of paradoxical arterial emboli of the extremities

BACKGROUND

The heart is the main source of arterial emboli (> 80%). The majority of remaining sources are arterioarterial or of unknown origin, with each accounting for 5% to 10% of cases. This study covers an 8-year period and analyzes the etiology of arterial emboli of the extremities, with emphasis on patients with paradoxical emboli.

METHODS

The hospital records of all patients were reviewed, with emphasis on patients with paradoxical emboli. The sources of emboli were classified as cardiac, arterioarterial, paradoxical emboli (fulfilled Johnson's criteria triad with cardiac defect and right-to-left shunting), possible paradoxical emboli (met two of Johnson's criteria), or unknown.

RESULTS

This series included a total of 406 cases, and the sources of emboli were as follows: 248 (61%) cardiac, 62 (15%) arterioarterial, 6 (2%) paradoxical emboli, 8 (2%) possible paradoxical emboli, and 82 (20%) had an unknown source or incomplete work-up. The mean age of paradoxical emboli patients was 39 years, in contrast to a mean of 68 years for the entire series. All 6 paradoxical emboli patients presented with acute ischemia of an extremity, symptoms of deep vein thrombosis or pulmonary embolism or both, and a documented patent foramen ovale with right-to-left shunting. None of the patients had evidence of cardiac or peripheral atherosclerotic disease. Their treatment included one or more of the following: embolectomy, lytic therapy, anticoagulation, caval filters, or closure of a patent foramen ovale.

CONCLUSIONS

Paradoxical emboli should be considered when the source of emboli is unknown, particularly in young patients. A complete work-up on these patients should include contrast saline or transesophageal echocardiography, lung scan, and peripheral venous imaging, particularly if conventional echocardiography and arteriography did not lead to a diagnosis.

Patent foramen ovale in young stroke patients with mitral valve prolapse

Because mitral valve prolapse and patent foramen ovale are supposed to promote stroke in young patients, we assessed the frequency of patent foramen ovale in 18 patients younger than 45 years with stroke and mitral valve prolapse diagnosed on echocardiography at the time of stroke, who were admitted to 2 university hospitals. Eleven patients were called back to hospital for contrast transthoracic and/or transesophageal echocardiography, 3 to 7 years after their initial stroke. A patient foramen ovale was found in 9 patients (50%). In 4 re-assessed patients no mitral valve prolapse was found using our present criteria. Six patients with mitral valve prolapse had a patent foramen ovale (43%). Our results suggest that mitral valve prolapse is commonly associated with patent foramen ovale in young stroke patients.

Usefulness of transesophageal echocardiography in unexplained cerebral ischemia

Two-hundred seventy consecutive patients with "unexplained cerebral ischemia" were studied with transesophageal echocardiography to determine the value of this test in identifying potential cardiac sources of cerebral embolism. The findings of this group were compared with those of 772 consecutive patients undergoing transesophageal echocardiographic evaluation for indications other than cerebral ischemia. This study also examined this group of patients with unexplained cerebral ischemia to determine differences in relation to underlying cardiac rhythm and patient age. Intracardiac thrombus, atrial septal aneurysm, patent foramen ovale, spontaneous left atrial contrast and protruding debris in the thoracic aorta were found more often in patients with unexplained cerebral ischemia. Wall motion abnormalities of the left ventricle, as well as mild to moderate valvular lesions including mitral valve prolapse, were found to be similar in both groups. Spontaneous left atrial contrast, as well as mild to moderate valvular abnormalities, were found more often in patients with atrial fibrillation (22% of the group with unexplained cerebral ischemia). However, the presence of intracardiac thrombus was no more frequent in patients with atrial fibrillation than in those with normal sinus rhythm. Patients aged > 50 years were found to have atrial fibrillation and larger left atrial size more often than their younger cohorts, as well as a greater incidence of valvular abnormalities and left ventricular wall motion abnormalities. Mitral valve prolapse was seen more frequently in the younger cohort of patients.

Impact of transesophageal echocardiography on the anticoagulation management of patients admitted with focal cerebral ischemia

Transesophageal echocardiography (TEE) improves the diagnostic accuracy of transthoracic echocardiography in the identification of potential cardiac sources of embolus. However, there are few studies of the impact of TEE on the medical management of patients with focal cerebral ischemia. The records of 52 consecutive, hospitalized patients undergoing both TEE and transthoracic echocardiography for suspected cardiac source of embolus were reviewed to determine the influence of TEE on the decision to anticoagulate patients. Of 52 patients, 39 had focal cerebral ischemia (transient ischemic attack, n = 9; acute cerebral infarction, n = 30). In 4 of these 39 patients (10%), the TEE results changed the management of anticoagulation. In 19 of 39 patients (49%), the TEE results helped confirm anticoagulation decisions, and in 16 (41%), the results had no effect on anticoagulation decisions, because of overriding clinical information. Ten of the latter 16 patients had TEE evidence for a possible source of an embolus, but were not anticoagulated; 5 of these were poor candidates for long-term anticoagulation, and the others had right-to-left shunting across a patent foramen ovale or an interatrial septal aneurysm. Clinical variables (atrial fibrillation, TEE findings and pre-TEE anticoagulation status) were considered as possible predictors of post-TEE anticoagulation status using logistic regression analysis; the strongest predictor of post-TEE anticoagulation status was pre-TEE anticoagulation status (p < 0.0005). Despite the selection of patients presumed to receive maximal benefit from TEE, this study suggests that TEE findings are not predictive of subsequent anticoagulation management. However, TEE is at least confirmatory of anticoagulation decisions in most cases.

Transthoracic echocardiography versus transesophageal echocardiography in detecting cardiac sources of embolism

Although the yield of potential cardiac sources of embolism by echocardiography in patients with stroke and arterial embolism has been low, with the advent of transesophageal echocardiography, a renewed enthusiasm for echocardiography in these patients has developed. This article reviews the six major studies comparing transthoracic to transesophageal echocardiography in the search for potential cardiac sources of embolism. The overall yield of transesophageal echocardiography in these studies for potential cardiac sources of embolism is 43% compared to 14% by transthoracic echocardiography in a total of 367 patients. In patients without clinical cardiac disease, the yield is lower but still substantially higher by transesophageal echocardiography (24% compared to 7% by transthoracic echocardiography). For left atrial thrombus, left atrial spontaneous contrast, patent foreman ovale, and atrial septal aneurysm (ASA), transesophageal echocardiography is clearly superior than transthoracic echocardiography. Data on the detection of mitral valve prolapse and left ventricular thrombus are conflicting and neither method is clearly superior. In addition, transesophageal echocardiography identifies certain abnormalities including debris in the aorta and prosthetic strands that transthoracic echocardiography is incapable of identifying. Although transthoracic echocardiography should continue to be the initial screening modality for stroke patients, transesophageal echocardiography should be performed when surface findings are negative or equivocal in patients with likely cardioembolic stroke.

Heart disease in patients with stroke: incidence, impact, and implications for rehabilitation. Part 1: Classification and prevalence

Heart disease is found in about 75% of patients who have suffered a stroke. Cardiovascular diseases can be risk factors, etiologic mechanisms, associated conditions, or direct consequences of stroke. Cardiac comorbidity may delay initiation of rehabilitation, complicate the course and care of the patient with stroke, inhibit participation in a therapeutic exercise program, limit functional outcomes, and contribute to early mortality in the individual with cerebrovascular disease. Part 1 of this two-part article describes the various forms of heart disease that may be seen in stroke patients, and reviews the incidence figures for each type of associated cardiac condition.

Stroke in young adults. A continuing diagnostic challenge

Cerebrovascular disease in persons between 15 and 45 years of age is on the rise and represents a diagnostic challenge. With a thorough investigation, the cause of cerebral ischemic infarction or nontraumatic intracerebral hemorrhage can be identified in most cases and appropriate treatment can be administered. Subarachnoid hemorrhage is usually caused by ruptured saccular aneurysm, but misdiagnosis continues to be a problem. Angiography performed early in the course of illness is a safe diagnostic procedure in young adults with any type of cerebrovascular disease. Overall prognosis for young adults with cerebrovascular disease varies with the underlying disorder but is generally good.

René Descartes 1596-1650

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Cost-effective investigation of patients with suspected transient ischaemic attacks

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Etiopathogenesis and prognosis of cerebral ischemia in young adults. A survey of 155 treated patients

Etiology and long-term prognosis were prospectively investigated in 155 consecutive patients (96 men and 59 women), aged 16 to 45 years, referred to our Neurosurgical Unit with cerebral transient ischemic attacks or infarction during the period 1978-1988. All patients underwent neurological and medical-cardiological evaluation, cerebral computerized tomography scanning, electrocardiogram, and laboratory tests. Two-dimensional echocardiography was performed in 123 cases (79%), cerebral angiography in 147 (95%). Atherosclerosis was the leading etiology occurring in 48 patients (31%). A cardioembolic disorder was considered the probable cause of ischemia in 8 cases (5.1%). Further possible etiologies were contraceptive pill assumption (5.8% of the total, but 15.3% within the female group), spontaneous arterial dissection (4.5%), migraine (4%), puerperium (2.6%), cervical trauma (2.6%), and other, more uncommon conditions. Despite extensive evaluation, the cause of cerebral ischemia remained unknown in 40% of cases. All patients received antiplatelet medication and 16 underwent surgery. The long-term outcome at a mean follow-up of 5.8 years was favorable: 91% of subjects resumed their work on a full or part-time basis.

Failure to awaken after general anaesthesia secondary to paradoxical venous embolus

A patient is presented who failed to regain consciousness after an apparently uneventful nine-hour revision of a total hip replacement. There were no clinically important haemodynamic changes during the operation, and oxygen saturation, capnography and acid base balance were normal throughout. Postop CT of the head showed a large left MCA infarct with midline shift. At autopsy, the patient was found to have a previously unsuspected patent foramen ovale, and a venous embolus in the left internal carotid artery, which probably had originated from the periprostatic venous plexus with a large infarct in the distribution of the left anterior and middle cerebral arteries. The authors conclude that massive paradoxical venous emboli can occur during surgery with minimal haemodynamic changes.

Superiority of transesophageal echocardiography in detecting cardiac source of embolism in patients with cerebral ischemia of uncertain etiology

The diagnostic yield of transesophageal and transthoracic echocardiography for identifying a cardiac source of embolism was compared in 79 patients presenting with unexplained stroke or transient ischemic attack. There were 35 men and 44 women with a mean age of 59 years (range 17 to 84); 52% had clinical cardiac disease. Both transthoracic and transesophageal echocardiograms were performed using Doppler color flow and contrast imaging. Transesophageal echocardiography identified a potential cardiac source of embolism in 57% of the overall study group compared with only 15% by transthoracic echocardiography (p less than 0.0005). Compared with transthoracic echocardiography, transesophageal echocardiography more frequently identified atrial septal aneurysm associated with a patent foramen ovale (9 versus 1 of 79 patients, p less than 0.005), left atrial thrombus or tumor (6 versus 0 of 79 patients, p less than 0.05) and left atrial spontaneous contrast (13 versus 0 of 79 patients, p less than 0.0005). All cases of left atrial thrombus or spontaneous contrast were identified in patients with clinically identified cardiac disease. In the 38 patients with no cardiac disease, transesophageal echocardiography identified isolated atrial septal aneurysm and atrial septal aneurysm with a patent foramen ovale more frequently than transthoracic echocardiography (8 versus 2 of 38 patients, p less than 0.05). The two techniques had a similar rate of identifying apical thrombus and mitral valve prolapse. Overall, transesophageal echocardiography identified abnormalities in 39% of patients with no cardiac disease versus 19% for transthoracic echocardiography (p less than 0.005). Thus, transesophageal echocardiography identifies potential cardiac sources of embolism in the majority of patients presenting with unexplained stroke.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of imaging in the management of cerebral and ocular ischaemia

The last decade has seen several major technological advances in vascular neuroradiology, the most clinically significant of which have been the facility to image the brain and the extracranial carotid bifurcation noninvasively with accuracy and safety. Another major advance has been unequivocal evidence from formal statistical overviews that antiplatelet therapy, particularly aspirin, reduces the risk of serious vascular events by about 25%. These advances have changed clinical practice such that most patients presenting with symptoms suggestive of cerebral ischaemia should now have cranial CT to exclude intracerebral hemorrhage, not only because the causes and prognosis of cerebral ischaemia differ from those of intracerebral hemorrhage, but because many patients with cerebral ischaemia should be considered for antiplatelet therapy. Besides the use of long term antiplatelet therapy and control of vascular risk factors, other acute treatment options are limited with the possible exception of anticoagulation, thrombolysis, cytoprotective agents and carotid endarterectomy. If, as seems likely, the current clinical trials show that carotid endarterectomy plus medical therapy improve upon the stroke-free survival of patients treated medically, at least in symptomatic patients with severe stenosis, the number of carotid endarterectomies performed will increase considerably because carotid bifurcation disease is the most common cause of cerebral and ocular ischemic events. It will then be even more important to be able to obtain accurate anatomical and physiological information about the extracranial and intracranial circulations with utmost safety. Duplex ultrasound is currently the noninvasive screening method of choice for carotid bifurcation disease because it is available, relatively cheap, and reasonably accurate. It not only images the vessel lumen and degree of stenosis, but also the morphology of the vessel wall and associated plaque, the relevance of which is still uncertain in the pathogenesis of cerebral and ocular ischaemia. A major limitation of duplex sonography is that it cannot reliably distinguish tight stenosis from occlusion and it does not image the proximal or distal carotid circulation. The aim of newer techniques will be to distinguish tight extracranial carotid stenosis from occlusion and to provide anatomical, physiological and pathological information about the intracranial circulation and ischemic lesions (in view of potential for thrombolytic therapy of major intracranial vessel occlusion) with safety and reproducible accuracy.

Computed tomographic patterns of proven embolic brain infarctions

To define patterns of infarction on computed tomography that are characteristic of embolism, as opposed to hemodynamically or microangiopathically induced brain lesions, a consecutive series of 60 patients with acute brain embolism were studied. Strokes were embolic in origin; that is, hemodynamic and in situ thrombotic stroke mechanisms had been excluded. Embolically active, cardiac disease was proved in 42 and was clinically evident in 13 patients. Five patients had suffered a stroke due to catheter-related embolism. Computed tomography revealed pial artery territorial infarction in 55 patients (92%). In 5, the infarction had the size or location (or both) characteristic of lacunes, although shape and lack of multiplicity raised questions about this interpretation. No patient showed a low-flow type of infarction pattern. These findings strongly support the view that (1) except for in situ thrombosis, pial artery territorial infarctions are indicative of an embolic mechanism, and (2) that the mechanism underlying lacunes is hardly, if ever, embolic.

Brain cardioembolism. Issues in diagnosis and management

The diagnosis of cardioembolism is always based on circumstantial evidence. Echocardiography has a limited useful yield and should be reserved for young patients or older patients with clinical heart disease. Primary prophylaxis with anticoagulants appears to be reasonable for patients with acute anterior wall myocardial infarction, rheumatic valvular disease, or dilated cardiomyopathy and, possibly, for those with chronic nonvalvular atrial fibrillation. Secondary prophylaxis (after an initial embolism) is reasonable for the same conditions and, possibly, for mitral valve prolapse. Acute anticoagulation therapy is warranted when a large infarct is excluded by computed tomography 24 hours after a cerebral embolism.

Diagnosis of stroke in young adults

The cause of stroke in a young adult can usually be ascertained with proper workup. One of the most common causes is atherosclerotic cerebrovascular disease, and cigarette smoking is an important risk factor in young adults. Several types of nonatherosclerotic cerebral vasculopathy can also result in premature cerebral infarction; these include cervicocephalic arterial dissection, nonpenetrating traumatic arterial disease, moyamoya disease, fibromuscular dysplasia, vasculitis, and migraine. Cardiac embolism may play a more important role than was previously thought, and hematologic disorders (eg, sickle cell disease, polycythemia rubra vera, coagulation problems) are known to predispose patients to stroke. A careful history of risk factors and a thorough neurologic and cardiovascular examination followed by adequate testing, including angiography, are essential to diagnosis.