Cerebral angiographic study on C.V.D. in Japan

Risk Factors, Vascular Lesion Distribution, Outcome and Recurrence of Strokes Due to Intracranial Atherosclerosis: One Year Data from Hyderabad Stroke Registry

Background:

Intracranial atherosclerotic stenosis (ICAS) is a common cause of ischemic stroke in Asian countries and probably in India.

Aim:

The aim of this study was to describe the risk factors, distribution of vascular lesions, recurrence and outcome of stroke due to ICAS.

Methodology:

A total of 100 consecutive patients of ischemic stroke due to ICAS were enrolled prospectively from January 1, 2015, to December 31, 2015, and followed for 1 year for treatment compliance and recurrence. The details about demographics, risk factors, and vascular lesions were noted.

Results:

There were 68 males and 32 females. Hypertension (HTN), diabetes, alcohol, smoking, hyperlipidemia, and hyperhomocysteinemia was present in 82%, 52%, 34%, 33%, 28%, and 23%, respectively. The number of arteries involved were middle cerebral artery, 53 (37.3%); posterior cerebral artery, 24 (16.9%); internal cerebral artery, 21 (14.8%); vertebral artery, 18 (12.7%); basilar artery, 6 (4.2%); and anterior cerebral artery, 6 (4.2%). Seventeen (17%) patients had a recurrent stroke during 1 year follow-up. The presence of uncontrolled HTN and diabetes mellitus after discharge were significantly associated with stroke recurrence (P < 0.05). The use of dual antiplatelet agents and statins was found to have a significant effect in the prevention of recurrent stroke (P < 0.05). Severe stroke at presentation and presence of hemiparesis were the predictors for unfavorable outcome at 3 months (P < 0.05).

Conclusion:

Risk factors, distribution of vascular lesions and high recurrence of stroke due to ICAS in this study is similar to that reported from other Asian countries. Aggressive medical management and risk factor control remains the best strategy for preventing recurrence.

Magnetic resonance angiography findings in patients with ischemic stroke from North India

BACKGROUND

We sought to evaluate the magnetic resonance (MR) angiography (MRA) findings in patients with ischemic stroke (IS) from North India and correlate the changes with various conventional and nonconventional risk factors.

METHODS

The study took place at a tertiary care teaching hospital. The patients with IS were clinically evaluated including body mass index, dietary habits, and family history of stroke. MR imaging, MRA, and testing for blood sugar, lipid profile, B12, folic acid, and homocysteine were carried out. The MRA abnormalities were considered significant if stenosis was 50% or greater and these were categorized into extracranial (EC), intracranial (IC), or combined lesions. The location of infarct on MR imaging was also noted.

RESULTS

There were 151 patients whose median age was 60 (22-85) years. The EC MRA was abnormal in 56.3% and the IC MRA in 63.3% of patients, the internal carotid artery being the most common site. Corresponding infarct was present in 64.7% and noncorresponding in 45.3% of patients. The MRA abnormality positively correlated with hypertension and diabetes, and negatively with alcohol consumption. The EC MRA abnormality was more common in upper caste Hindus and Muslims and in the city dwellers.

CONCLUSION

In North Indian patients with IS, the frequency of EC and IC MRA abnormality lies between Whites and the Orientals.

Increasing frequency and burden of cerebral artery atherosclerosis in Korean stroke patients

PURPOSE

Koreans have been undergoing rapid lifestyle changes that may have an effect on patterns of cerebral artery atherosclerosis. This study was aimed at determining the frequency and distribution of atherosclerosis in the cerebral arteries and associated temporal changes over the past eight-year period among Korean stroke patients.

MATERIALS AND METHODS

By using stroke registry data registered between April 1999 and March 2007, we investigated the presence, severity, and location of cerebral artery atherosclerosis as determined by angiographic findings. Their annual patterns and association with vascular risk factors were investigated.

RESULTS

Of 1,955 patients, 1,517 patients (77.6%) demonstrated atherosclerosis in one or more arteries. A significantly increasing trend of atherosclerosis was observed during the past eight years, which was ascribed to an increase of combined extracranial (EC) and intracranial (IC) atherosclerosis. The number of atherosclerotic arteries increased as the number of risk factors increased. In the multivariate analysis, the year and vascular risk factors were independent predictors of the presence of atherosclerosis.

CONCLUSION

We found that the atherosclerotic burden has been increasing for the past eight years in Korean stroke patients, particularly the combined EC and IC subtype. Lifestyle changes and increase in vascular risk factors may be contributing factors.

Takayasu arteritis and giant cell arteritis: a spectrum within the same disease?

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) have been considered distinct disorders based on their clinical features, age of onset, and ethnic distribution. However, on closer examination, these disorders appear more similar than different. The histopathology of arterial lesions in these diseases may be indistinguishable. Imaging studies have revealed large vessel inflammation in at least 60% of patients with GCA. We questioned whether the distinctions between these diseases might in part be an artifact due to bias in gathering historical and physical data. We postulated that signs and symptoms of GCA and polymyalgia rheumatica occur in patients with TAK but have been under-reported as a result of this bias.We performed a retrospective review of 75 patients with TAK and 69 patients with GCA (per American College of Rheumatology criteria). Signs and symptoms attributable to disease within the year before and following diagnosis, treatment and interventional outcomes, and mortality were recorded using a standardized database. All cases were evaluated by a single physician, using identical history and physical examination forms for patients with both diseases.Patients were predominantly female (TAK 91%, GCA 82%) and white (TAK 88%, GCA 95%). New headache was a presenting symptom in 52% of TAK and in 70% of GCA patients. All TAK patients underwent vascular imaging studies and were demonstrated to have large vessel abnormalities. However, only a subset of patients with GCA (43/69, 62%) was similarly studied. Among this group, 73% of GCA patients had at least 1 arterial lesion identified. In both TAK and GCA, the most common sites of involvement were the aorta (TAK 77%, GCA 65%) and subclavian (TAK 65%, GCA 37%) arteries. Compared to patients with TAK, patients with GCA had a greater prevalence of jaw claudication (GCA 33%, TAK 5%), blurred vision (GCA 29%, TAK 8%), diplopia (GCA 9%, TAK 0%), and blindness (GCA 14%, TAK 0%).Symptoms, signs, and imaging abnormalities that are characteristic of GCA or TAK are often present, albeit in differing frequencies, in both disorders. These findings lend support to the hypothesis that these diseases may not be distinct entities, but represent skewed phenotypes within the spectrum of a single disorder. Differences in frequencies of manifestations may reflect a significant bias in how data are gathered for patients with each disease, as well as the influence of vascular and immunologic senescence.

Frequency and Outcome of Carotid Atheromatous Disease in Patients With Stroke in Pakistan

Background and Purpose— Limited data exist on the frequency and outcome of carotid artery disease in Pakistan. Such information would help guide the usefulness of screening for the condition in this low-middle income health care setting.

Methods— A prospective, descriptive study was conducted among 3 large teaching hospitals in Karachi, Pakistan. Patients referred for carotid Doppler ultrasound examination were included if they had experienced a stroke or TIA within the previous month. The severity and morphology of carotid disease were characterized by trained technicians using standardized criteria. Demographic and risk factor data were collected at baseline, and the outcome of patients was assessed at least 6 months later.

Results— A total of 672 patients underwent bilateral carotid Doppler ultrasound (1344 carotid examinations). The findings revealed 0% to 50% stenosis in 526 (78%), 51% to 69% stenosis in 57 (8%), 70% to 99% stenosis in 82 (12%), and total occlusion in 7 patients (1%). Potentially surgically correctable disease, defined as 70% to 99% carotid artery stenosis, was present in only 79 (12%) patients, of whom 47 (60%) were ipsilateral symptomatic, 15 (20%) asymptomatic, and 17 (20%) had status unknown. Outcome information at ≥6 months follow-up was available for 36 of the 47 (76%) surgically correctable and only 4 of these patients (12%) had undergone surgical or radiological intervention (carotid endarterectomy in 3 patients and carotid stenting in 1 patient).

Conclusion— The frequency of carotid artery disease of at least moderate severity is very low in patients with recent stroke or TIA and there is low utilization of high-cost, carotid intervention procedures in Pakistan. These data raise questions regarding the applicability and cost-effectiveness of routine carotid ultrasound screening in our country and similar population in Asia. The local socio-economic and clinical data do not support routine carotid Doppler ultrasound in every patient with stroke and TIA in Pakistan. Studies are warranted to determine predictors of significant carotid artery stenosis in stroke/TIA patients of our country to develop reliable stroke guidelines appropriate for local population.

Clinical features and risk factors in stroke in young

A total of 251 young patients (less than 40 years) with stroke were admitted during a 7-year period and investigated. These constituted 30% of the total stroke patients admitted to this hospital. Among the young, 63% of strokes were of nonembolic occlusive group. Hemorrhagic strokes were observed in 26% cases. This study revealed that concurrent infection, nonspecific arteritis, diabetes mellitus and hypertension contribute very little to the stroke in younger population. However, cholesterol, beta-lipoproteins, triglycerides, platelet adhesiveness and platelet aggregation were significantly increased in some of the clinical groups.

Prevalence of carotid artery stenosis in patients with coronary artery disease in Japanese population

BACKGROUND AND PURPOSE

Prevalence of carotid artery stenosis in patients with coronary artery disease (CAD) is unknown in Japanese population.

METHODS

The study populations consisted of 632 consecutive patients who underwent coronary angiography because of suspicion of CAD. All patients underwent carotid ultrasonography to screen carotid artery stenosis before coronary angiography. We defined echographic carotid stenosis as area stenosis of >50% or peak systolic velocity of >200 cm/s.

RESULTS

Echographic carotid stenosis was observed in 124 patients (19.6%). Coronary angiography revealed 433 patients had CAD. Prevalence of echographic carotid artery stenosis was 14 of 199 (7.0%), 18 of 124 (14.5%), 28 of 131 (21.4%), and 64 of 178 (36.0%) in patients with 0-, 1-, 2-, and 3-vessel CAD, respectively (P<0.0001). The prevalence rate with carotid stenosis and CAD was 25.4%. Multivariate stepwise logistic regression analysis showed that age and the extent of CAD were independently related to the presence of carotid stenosis (P=0.0002 and <0.0001, respectively).

CONCLUSIONS

Prevalence of carotid stenosis in patients with CAD is high in Japan as well as in Western countries. Screening of carotid artery stenosis is recommended especially in older patients with multivessel CAD.

Intracranial atherosclerosis: incidence, diagnosis and treatment

Intracranial atherosclerosis is considered a cause of approximately 8% of all strokes in the western society. However, its frequency is much higher in Asian countries. In our hospital-based study, among the patients who had angiographic abnormalities, the frequency of intracranial atherosclerosis was approximately 70% far exceeding that of extratracranial atherosclerosis. Symptomatic atherosclerotic diseases were most often found in the middle cerebral artery. Generally, it has been shown that obesity and hyperlipidemia are related to extracranial diseases while advance hypertension is associated with intracranial diseases. However, these results have not always been replicated, and certain genetic factors may be related with the ethnic differences in the location of atherosclerosis. Recent studies using diffusion weighted MRI showed that the main mechanisms of stroke in patients with intracranial atherosclerosis are the branch occlusion, artery to artery embolism and both. The intracranial stenosis, especially symptomatic one, is not a static condition and may progress or regress in a relatively short period of time. Progressive stenosis of intracranial arteries is clearly related to the development of ischemic events. The annual risk of stroke relevant to the stenosed intracranial vessel is approximately 8%. In retrospective studies including ASID, anticoagulation was found to be superior to aspirin in reducing the stroke events. However, a recent prospective study failed to confirm the superiority of anticoagulation over aspirin in patients with intracranial stenosis. Moreover, anticoagulation resulted in excessive central nervous system bleeding as compared to aspirin. Because aspirin alone seems to be insufficient in the prevention of progression of intracranial stenosis, a combination of antiplatelets has been tried. Recently, we found that a combination of aspirin + cilostazol was superior to aspirin monotherapy in the prevention of progression of symptomatic intracranial stenosis. However, further studies are required to find out the best combination of antiplatelets for symptomatic intracranial stenosis. The effect of other atheroma stabilizers such as statins should also be properly evaluated. Angioplasty/stent is another important option for the relatively severe intracranial stenosis. According to previous studies, immediate success rate has reached up to 90%. If patients are carefully selected, and procedures done by experienced hand, angioplasty/stent can be of benefit especially in relatively young patients with proximal, short-segment, severe symptomatic stenosis. However, this procedure is not without complications or long-term re-stenosis. Further studies are required to elucidate the best therapeutic strategy in patients with intracranial atherosclerosis.

Effects of carotid endarterectomy on cerebral blood flow and neuropsychological test performance in patients with high-grade carotid stenosis

We examined the changes in cognitive function following carotid endarterectomy (CEA) in relation to the cerebral blood flow (CBF) in patients with high-grade carotid stenosis. The subjects consisted of 23 patients who underwent CEA and 17 controls matched by age and education. Single photon emission computed tomography (SPECT) and neuropsychological tests were performed 2 weeks before and 4 weeks after CEA in all patients. The preoperative CBF tests revealed a decreased vasodilatory reserve in the ipsilateral cerebral hemisphere in nine patients, which was increased after CEA. In these patients, the grade of carotid stenosis was significantly higher than in those with a normal perfusion reserve (90.2+/-8.1% vs. 78.6+/-11.3%, respectively, p<0.05). In the patient group, the postoperative scores (27.2+/-2.9) of the mini-mental state examination (MMSE) improved significantly over the preoperative ones (26.1+/-3.2, p<0.05). Moreover, the scores in the block-design test after CEA (86.8+/-19.8) were significantly higher than those before the operation (81.8+/-22.3, p<0.01). The error score in immediate retention improved from 9.0+/-3.1 to 7.7+/-4.0 following CEA (p<0.05). In the control group, none of the test scores showed significant improvement between the first and second tests. In the patients with an impaired vasodilatory reserve, the mean score of the block-design test significantly improved from 65.6+/-22.1 to 74.0+/-19.2 after CEA compared with those in patients without impairment (p<0.05). High-grade carotid stenosis was thus concluded to cause cognitive impairment due to cerebral hemodynamic failure, which is presumably reversed by CEA.

Vascular risk factors for atherosclerotic lesions of the middle cerebral artery detected by magnetic resonance angiography (MRA)

OBJECTIVES

To examine the relationship between atherosclerotic lesions of the middle cerebral artery (MCA) detected on MRA and vascular risk factors.

MATERIAL AND METHODS

We retrospectively assessed 279 patients (mean age, 69.0+/-11.3 years) who visited the Department of Neurology of Masuda Red Cross Hospital and underwent three-dimensional, time-of-flight MRA of the head between January 1996 and October 1998. Cases of cerebral embolism and internal carotid artery occlusion were excluded. Diagnoses were cerebral infarction (n = 152) and others (n = 127). We evaluated stenotic or occlusive lesions of the MCA (M1 portion), using MRA. Age, sex, history of hypertension, HbA1c, total cholesterol, fasting triglyceride, high density lipoprotein, lipoprotein(a), blood pressure, hematocrit, smoking and left ventricular hypertrophy (LVH) on ECG were included in the analysis.

RESULTS

36 patients (12.9%) had stenotic or occlusive lesions of the MCA on MRA. Univariate analysis showed that age, hypertension and HbA1c were significantly correlated with MCA lesions. Multiple logistic regression analysis showed that HbA C and hypertension were significant and independent predictors for MCA lesions.

CONCLUSION

Hypertension and high serum HbAlc levels may contribute to the development of atherosclerotic lesions of the MCA in Japanese people.

Subtypes of ischemic stroke. A hospital-based stroke registry in Taiwan (SCAN-IV)

BACKGROUND AND PURPOSE

To better understand the clinical pattern and further elucidate the risk factors and outcome in different subtypes of cerebral infarction (CI) of the Chinese in Taiwan, we analyzed the National Taiwan University Hospital Stroke Registry in 1995 and performed an ethnic comparison with similar data banks.

METHODS

From the National Taiwan University Hospital Stroke Registry in 1995, 676 patients (383 men and 293 women; mean age, 64.9 years; SD, 13.8 years; range, 1 to 98 years) with CI were recruited for this analysis. CI was classified into five subtypes based on clinical manifestations, ultrasonographic studies, and neuroimaging findings: large-artery atherosclerosis, lacunae, cardioembolism, other less common determined causes, and undetermined cause. Vascular risk factors, extracranial carotid artery atherosclerosis, and 30-day case-fatality rates were investigated in each subtype of CI.

RESULTS

Of all CI patients, 17%, 29%, 20%, 6%, and 29% were classified as large-artery atherosclerosis, lacunae, cardioembolism, other determined causes, and undetermined cause subtypes, respectively. The present results were compared with those from eight similar Western stroke registries. The relative incidence of lacunar CI in Chinese patients was more common, but large-artery atherosclerotic CI was less common than in whites. Hypertension was frequently seen in CI patients, especially in those with lacunae (85%) and large-artery atherosclerosis (69%). Patients with cardioembolism had a higher percentage of atrial fibrillation (69%), left ventricular hypertrophy, and ischemic heart disease than the other patients. Patients with large-artery atherosclerosis had more vascular risk factors, such as hypertension, diabetes mellitus, smoking, and carotid stenosis. Cardioembolic patients had higher case-fatality rates than other CI patients. Of the cardioembolic patients, 17.3% and 21.8% died within 30 days and during hospitalization, respectively.

CONCLUSIONS

The proportion of CI subtypes varied in different stroke registries. This may be partly due to applied classification criteria and racial-ethnic differences. Awareness of the risk factors and outcome in each subtype of stroke may afford further insights into the surveillance and treatment of cerebrovascular disease.

Prevalence of asymptomatic carotid atherosclerotic lesions detected by high-resolution ultrasonography and its relation to cardiovascular risk factors in the general population of a Japanese city: the Suita study

BACKGROUND AND PURPOSE

Because extracranial carotid atherosclerotic lesions have been considered rare, no reports have been published on the prevalence and distribution of these lesions in a general Japanese population. However, recent changes in lifestyle are thought to have caused an increase in these lesions. The aim of this study was to use high-resolution ultrasonography to examine the prevalence of asymptomatic extracranial carotid artery lesions and its relation to cardiovascular risk factors in an urban Japanese population.

METHODS

The subjects were 814 men and 880 women aged 50 to 79 years randomly sampled from the residents of Suita, a city located in the second largest urban area of Japan. Asymptomatic carotid lesions were detected and evaluated by a single physician with high-resolution B-mode ultrasonography.

RESULTS

We found significant sex differences in the prevalence of atherosclerotic lesions in the extracranial carotid artery; 4.4% of all the subjects, 7.9% of the men, and 1.3% of the women had atherosclerosis accompanied by stenosis of >50%. A strong association between these lesions and the results of a 75-g oral glucose tolerance test was found in both sexes. Multiple regression analysis of carotid atherosclerosis showed significant relationships with age, systolic blood pressure, fasting blood glucose, pack-years of smoking, total serum cholesterol, and HDL cholesterol in men (P<.05) and significant relationships with age, systolic blood pressure, pack-years of smoking, and total serum cholesterol in women (P<.05).

CONCLUSIONS

Our data showed that cardiovascular risk factors were strongly related to carotid atherosclerosis and that the proportion of severe carotid atherosclerosis with >50% stenosis was not low and was almost equal to that reported in developed western countries.

Evaluation of intracranial and extracranial carotid steno-occlusive diseases in Taiwan Chinese patients with MR angiography: preliminary experience

BACKGROUND AND PURPOSE

We attempted to evaluate the location of vascular lesions in cases of cerebrovascular steno-occlusive diseases in Chinese persons living in Taiwan.

METHODS

With three-dimensional time-of-flight magnetic resonance angiography (MRA) as a screening tool, 108 symptomatic patients with cerebrovascular steno-occlusive diseases were examined. Cardioembolic disease and cerebral hemorrhage cases were excluded. The degrees of stenosis of bilateral cervical carotid arteries and their major intracranial tributaries were recorded. They were categorized as nonsignificant stenosis (0% to 49%), significant stenosis (50% to 99%), and total occlusion.

RESULTS

Our data revealed that 32.4% of the cases were normal in either cervical carotid arteries or their intracranial tributaries. In 24.1% of the cases, significant extracranial carotid stenosis or occlusion was the only finding on MRA. In 25.9% of the cases, only significant intracranial-tributary stenosis was found. In 17.6% of them, significant lesions were found in both extracranial and intracranial carotid artery tributaries.

CONCLUSIONS

A racial difference between Chinese and white patients in location of lesion in cerebrovascular steno-occlusive diseases was confirmed. About one third of symptomatic Chinese patients living in Taiwan showed small-vessel disease. Approximately 24% of patients had only extracranial carotid disease, and about 26% had only intracranial carotid tributary disease. We need a larger series of patients to confirm these findings. However, MRA might be a good screening tool for steno-occlusive cerebrovascular disease, especially in persons of a race with more intracranial carotid disease, such as the Chinese.

Increase in extracranial atherosclerotic carotid lesions in patients with brain ischemia in Japan. An angiographic study

BACKGROUND AND PURPOSE

Atherosclerotic lesions in the cerebral arteries are distributed heterogeneously among different races. Intracranial carotid lesions are reported to be more common than extracranial carotid lesions among Japanese people, which is in sharp contrast to the pattern of cerebral atherosclerosis in whites. However, several Japanese clinicians have the impression, which has yet to be clinically proven, that extracranial carotid diseases are recently increasing in number.

METHODS

One hundred twenty-one patients who developed ischemic stroke and underwent angiography were examined in the study. Seventy were admitted to our clinic from 1963 to 1965 (early group); the remaining 51 patients were seen from 1989 to 1993 (recent group). Angiographic findings and vascular risk factors were compared between the two groups.

RESULTS

Severe atherosclerotic lesions of the extracranial internal carotid arteries increased significantly during the ensuing 24 years between the end of the first period until the beginning of the second period (from 1965 to 1989), whereas lesions in the intracranial carotid system were similar between the two groups. Severe atherosclerosis in the extracranial internal carotid artery was more frequent in patients with diabetes mellitus, which proved to be the only risk factor that showed a temporal increase.

CONCLUSIONS

The proportion of severe atherosclerosis in Japanese patients with brain ischemia has been increasing in the extracranial internal carotid artery, while that in the intracranial carotid system remains unchanged. Such a temporal change may be the result, at least in part, of an increase in the prevalence of diabetes mellitus.

Pattern of cerebral atherosclerosis in Hong Kong Chinese. Severity in intracranial and extracranial vessels

BACKGROUND AND PURPOSE

The clinical pattern of stroke and the angiographic distribution of cerebral atherosclerosis in Chinese are different from those in Caucasians. Pathological data from autopsy studies are lacking.

METHODS

The intracranial and extracranial arteries supplying the brains of 114 consecutive Chinese patients undergoing autopsy in a regional general hospital were examined by computer-assisted morphometric analysis under a microscope as well as by macroscopic grading for atherosclerotic narrowing. The severity was correlated with various atherosclerosis-related factors.

RESULTS

Atherosclerosis of the intracranial cerebral vessels was more severe than that of the extracranial vessels. The distal branches of the intracranial vessels were also commonly involved. Hypertension and diabetes mellitus were identified as factors associated only with intracranial atherosclerosis (p < 0.001), whereas ischemic heart disease was associated with atherosclerosis in both the intracranial (p < 0.001) and extracranial (p = 0.012) vessels. Smoking was associated with narrowing of the extracranial vessels only (p = 0.0054).

CONCLUSIONS

Compared with figures from Caucasian and Japanese populations, the extent of intracranial atherosclerosis is much more severe in Hong Kong Chinese, whereas atherosclerotic narrowing of the extracranial carotid artery is less severe in Hong Kong Chinese than in Caucasians.

Racial differences in the distribution of posterior circulation occlusive disease

We compared clinical and arteriographic features in 27 white and 24 black patients with symptomatic posterior circulation occlusive disease. The degree of arterial stenosis was measured independently by two examiners at 12 sites within the vertebrobasilar territory. Racial comparisons were made based upon the distribution of extra- and intracranial occlusive lesions and symptomatic sites of the lesions. White patients had significantly more angina pectoris, more lesions of the origin of the left vertebral artery and more high grade lesions of the extracranial vertebral arteries. Black patients had significantly higher mean diastolic blood pressure, more diabetes mellitus, more lesions of the distal basilar artery, more high grade lesions of intracranial branch vessels and more symptomatic intracranial branch disease. Race was found to be the only factor increasing the risk of intracranial posterior circulation occlusive disease. Knowledge of the contribution of race to the distribution of posterior circulation lesions will help guide evaluation and treatment strategies for patients with vertebrobasilar occlusive disease.

Patterns of cerebrovascular disease in Japanese and other population groups in Hawaii: an angiographical study

Angiograms of the carotid system were analyzed for incidence and type of intracranial and extracranial lesions in 296 patients with a final diagnosis of non-hemorrhagic stroke. These patients represent all the major ethnic groups in Hawaii. A significant difference was found between the ratio of frequency of involvement of the extracranial and intracranial vessels in Caucasian and that in the Hawaiian-born Japanese populations, similar to that reported by others in native Japanese. The Filipino, Chinese, Hawaiian and part-Hawaiian populations showed no such significant difference.