Cerebral blood flow in nondemented elderly subjects with extensive deep white matter lesions on magnetic resonance imaging

Our previous study showed that deep white matter lesions (DWML) were associated with subtle cognitive decline in community-dwelling elderly people. However, even extensive (EXT)-DWML, found in 7 (4%) of 178 subjects aged 60 years or older, did not cause dementia. The purpose of the present study was to investigate brain circulation in nondemented elderly subjects with EXT-DWML. We compared cerebral blood flow in the deep white matter and frontal cortex between 5 subjects with EXT-DWML and 5 without such lesions, using a xenon-enhanced computed tomography (CT) method. Although the difference of deep white matter findings on magnetic resonance imaging (MRI) was the greatest possible (i.e., extensive v no or minimum lesions), cerebral blood flow values in anterior deep white matter and frontal cortex were 21.4 ± 5.3 standard deviation (SD) mL/100 g/minute and 42.7 ± 4.1, respectively, in subjects with extensive lesions, which were not significantly different from 24.3 ± 4.3 and 44.0 ± 7.1 in subjects without DWML. The present study suggests that EXT-DWML in nondemented elderly individuals do not necessarily indicate apparent hypoperfusion or marked cognitive decline.     

Plasma amyloid beta, apolipoprotein E, lacunar infarcts, and white matter lesions

Lacunar brain infarcts and cerebral white matter lesions are frequently observed on magnetic resonance imaging scans in elderly subjects. These lesions are also frequent in patient with cerebral amyloid angiopathy. We examined whether plasma amyloid beta peptide (Abeta) levels are associated with lacunar infarcts and white matter lesions in the general population, and whether the apolipoprotein E (APOE) genotype modifies these associations. We studied 1,077 participants within the population-based Rotterdam Scan Study, who were 60 to 90 years of age and free of dementia. Cross-sectional associations were analyzed by regression models with adjustments for age, sex, creatinine levels, and hypertension. In APOE epsilon4 carriers, plasma Abeta levels were positively associated with lacunar infarcts and white matter lesions, whereas in noncarriers no associations were observed. Per standard deviation increase in Abeta(1-40) and Abeta(1-42) levels the odds ratios for lacunar infarcts were 1.72 (95% confidence interval [CI] = 1.22-2.43) and 1.93 (95% CI = 1.31-2.85), the periventricular white matter lesion grade increased by 0.32 (95% CI = 0.08-0.57) and 0.29 (95% CI = 0.00-0.57), and the subcortical white matter lesion volume increased by 0.48 ml (95% CI = 0.04-0.91) and 0.24 ml (95% CI = -0.27-0.75). Higher Abeta levels are associated with more lacunar infarcts and white matter lesions in elderly subjects who carry an APOE epsilon4 allele.     

Neuropathological assessment of the lesions of significance in vascular dementia

OBJECTIVES—To better define the neuropathology ofvascular dementia.
METHODS—The neuropathological findings in 18 elderly, undemented subjects free of cerebrovascular disease werecompared with 19 elderly undemented subjects who had cerebrovasculardisease (many of whom had had a "stroke") and 24 elderly dementedsubjects who had cerebrovascular disease, but no other pathology toaccount for dementia. Cases in all groups were selected for absence orno more than very mild Alzheimer type pathology.
RESULTS—Microvascular brain damage in the form ofsevere cribriform change and associated subcortical white matter damageand microinfarction were correlated with a history of dementia. Severecribriform change was much more common and microinfarction somewhatmore common in the demented group with vascular disease than theundemented group with vascular disease (P=0.0006 and P=0.031respectively). Other findings of note were that congophilic angiopathyhad a greater prevalence in the vascular dementia group than thecontrol group, single cerebral infarcts were more common in the group who were undemented with vascular disease than in the group with dementia and vascular disease (P=0.0028), and the last group lacked evidence of macroscopic infarction more often than the first (P=0.034). There was a non-significant trend for the ratio ofinfarcted:uninfarcted tissue in one cerebral hemisphere to be higher inthe group with dementia and vascular disease than in the group withvascular disease but no dementia.
CONCLUSIONS—Microvascular disease, not macroscopicinfarction, was the chief substrate of vascular dementia in this seriesof cases.

     

Silent brain infarcts: A cause of depression in the elderly?

The present study included 1047 elderly participants. At baseline, brain magnetic resonance imaging (MRI) was performed to detect infarcts and white matter lesions; further, depressive disorders were assessed. Participants were followed up during 3.6 years to determine incident and recurrent depression. We found an increased risk of recurrent depression associated with silent brain infarcts.     

Plasma total homocysteine levels and cranial magnetic resonance imaging findings in elderly persons: the Cardiovascular Health Study

BACKGROUND: An elevated plasma total homocysteine (tHcy) level is associated with an increased risk of vascular disease. Some studies have shown associations between tHcy level and small-vessel disease of the brain on magnetic resonance imaging (MRI). DESIGN: In the Cardiovascular Health Study, 622 elderly participants without a history of transient ischemic attack or stroke had results for tHcy level and cranial MRI. We sought associations between tHcy level and MRI findings of ventricular grade, sulcal grade, white matter grade, and infarcts. We controlled for other factors, including levels of creatinine, folate, and vitamins B(6) and B(12) and methylenetetrahydrofolate reductase genotype. RESULTS: After controlling for age and sex, tHcy level was not associated with the individual MRI findings. Further adjustments for other factors and other blood tests had little effect on these findings. The only significant finding was a linear trend across quintiles of tHcy level and a pattern of MRI findings combining infarcts and high white matter grade. The linear trend remained significant after controlling for other risk factors and atherosclerotic markers (top quintile vs bottom quintile odds ratio, 3.3; 95% confidence interval, 0.96-11.20; P =.04 for linear trend) but was slightly diminished after further controlling for creatinine, folate, and vitamins B(6) and B(12) (odds ratio, 3.2; 95% confidence interval, 0.81-13.10; P =.07 for linear trend). CONCLUSION: We were unable to confirm the results of previous studies with respect to tHcy level and individual MRI findings, although an association was seen for an MRI pattern combining infarcts and high white matter grade.     

Cluster analysis and patterns of findings on cranial magnetic resonance imaging of the elderly: the Cardiovascular Health Study

OBJECTIVE: To characterize patterns of findings on cranial magnetic resonance imaging (MRI) of the elderly using a statistical technique called cluster analysis. SUBJECTS AND METHODS: The Cardiovascular Health Study is a population-based, longitudinal study of 5888 people 65 years and older. Of these, 3230 underwent cranial MRI scans, which were coded for presence of infarcts and grades for white matter, ventricles, and sulci. Cluster analysis separated participants into 5 clusters based solely on patterns of MRI findings. Participants comprising each cluster were contrasted with respect to cardiovascular risk factors and clinical manifestations. RESULTS: One cluster was low on all the MRI findings (normal) and another was high on all of them (complex infarcts). Another cluster had evidence for infarcts alone (simple infarcts), whereas the last 2 clusters lacked infarcts, one having enlarged ventricles and sulci (atrophy) and the other having prominent white matter changes and enlarged ventricles (leukoaraiosis). Factors that distinguished these clusters in a discriminant analysis were age, sex, several measures of hypertension, internal carotid artery wall thickness, smoking, and prevalent claudication before the MRI. The atrophy group had the highest percentage of men and the normal group had the lowest. Cognitive and motor performance also differed across clusters, with the atrophy cluster performing better than may have been expected. CONCLUSIONS: These MRI patterns identified participants with different vascular disease risk factors and clinical manifestations. Results of these exploratory analyses warrant consideration in other populations of elderly people. Such patterns may provide clues about the pathophysiology of structural brain changes in the elderly.     

Microalbuminuria is a risk factor for cerebral small vessel disease in community-based elderly subjects

Microalbuminuria (MA) is known as a marker for generalized vascular dysfunction. It occurs most commonly in the setting of diabetes and hypertension; however, its association with cerebral small vessel disease (SVD) in community-based elderly remains to be clarified. In this cross-sectional analysis, we evaluated the association between MA and cerebral SVD in total 651 community-based elderly subjects. We assessed cardiovascular risk factors by interviews and physical examinations, including an evaluation of urinary albumin creatinine ratio (UACR). All subjects underwent brain magnetic resonance imaging (MRI) and carotid ultrasonography. As endothelial markers, the serum levels of thrombomodulin (TM) and a tissue-type plasminogen activator/ plasminogen activator inhibitor-1 complex were also studied. The mean TM and UACR were higher in subjects with lacunar infarcts or with moderate white matter hyperintensities (mWMH) on MRI than in those without them. Additionally, the prevalence of lacunar infarcts or mWMH was higher in the highest tertile of UACR level than in the lowest or middle tertile. Furthermore, in logistic regression analysis, the elevation of logarithmically transformed UACR (log UACR) was associated with the higher likelihood for total lacunar infarcts (odds ratio [OR], 1.85 per one log UACR increase), multiple lacunar infarcts (OR, 1.89 per one log UACR increase), and mWMH (OR, 2.15 per one log UACR increase). The present study revealed that levels of urinary albumin are associated with cerebral SVD, independently of traditional cerebrovascular risk factors, in community-based elderly.     

Homocysteine, silent brain infarcts, and white matter lesions: The Rotterdam Scan Study

Silent brain infarcts and white matter lesions are frequently seen on magnetic resonance imaging in healthy elderly people and both are associated with an increased risk of stroke and dementia. Plasma total homocysteine may be a potentially modifiable risk factor for stroke and dementia. We examined whether elevated total homocysteine levels are associated with silent brain infarcts and white matter lesions. The Rotterdam Scan Study is a population-based study of 1,077 people aged 60 to 90 years who had cerebral magnetic resonance imaging. The cross-sectional relation of total homocysteine with silent infarcts and white matter lesions was analyzed with adjustment for cardiovascular risk factors. The mean plasma total homocysteine level was 11.5 micromol/l (standard deviation 4.1). The risk of silent brain infarcts increased with increasing total homocysteine levels (odds ratio 1.24/standard deviation increase, 95% confidence interval 1.06-1.45). The severity of periventricular white matter lesions and extent of subcortical white matter lesions were also significantly associated with total homocysteine levels, even after excluding those with silent brain infarcts. The overall risk of having either a silent brain infarct or severe white matter lesions was strongly associated with total homocysteine levels (odds ratio 1.35/standard deviation increase, 95% confidence interval 1.16-1.58). We concluded that total homocysteine levels are associated with silent brain infarcts and white matter lesions independent of each other and of other cardiovascular risk factors.     

Homocysteine and cognitive function in the elderly: the Rotterdam Scan Study

BACKGROUND: Elevated plasma total homocysteine (tHcy) concentrations are associated with AD and vascular dementia, but the relation with cognitive performance in nondemented elderly people is not known. OBJECTIVE: To examine the association of tHcy and cognitive function in the elderly, and assess whether this may be mediated by structural brain changes on MRI. METHODS: The Rotterdam Scan Study is a population-based study of 1,077 nondemented elderly. Cognitive performance was assessed, and compound scores were constructed for psychomotor speed, memory function, and global cognitive function. Cerebral infarcts, white matter lesions, and generalized brain atrophy were measured on MRI. The cross-sectional relationship between tHcy levels and neuropsychological test scores was assessed by multiple regression. RESULTS: Mean tHcy level was 11.5 micro mol/L (SD 4.1). Increasing tHcy levels were associated with lower scores for psychomotor speed, memory function, and global cognitive function, and this was largely due to the association with tHcy levels in the upper quintile (>14 micro mol/L). Adjusted differences between test scores of participants in the upper quintile as compared with the lower four quintiles of tHcy were -0.26 (95% CI: -0.37; -0.14) for psychomotor speed, -0.13 (95% CI: -0.27; 0.01) for memory function, and -0.20 (95% CI: -0.30; -0.11) for global cognitive function. These associations were not mediated by structural brain changes on MRI. CONCLUSION: Elevated tHcy levels are associated with decreased cognitive performance in nondemented elderly people, and the relation was most marked for psychomotor speed. This association was independent of structural brain changes on MRI.     

Increased brachial-ankle pulse wave velocity is independently associated with risk of cerebral ischemic small vessel disease in elderly hypertensive patients

OBJECTIVE: Increased arterial stiffness is an independent predictor of cardiovascular diseases in hypertensive patients. Hypertension and aging can cause similar damage to small vessel walls. The objective of this study was to determine relationship between arterial stiffness measured by brachial-ankle pulse wave velocity (baPWV) and the risk of cerebral small vessel disease (SVD) in elderly people with hypertension. METHODS: We studied 196 elderly subjects with hypertension (> or =50 years of age) who had neither large vessel stroke nor cardiac embolism. These patients were divided into three groups based on the results of brain MRI: (1) those with first-ever small vessel stroke; (2) those with asymptomatic subcortical ischemia; and (3) a control group with hypertension. RESULTS: The baPWV was significantly increased in the patients with first-ever small vessel stroke or asymptomatic subcortical infarction when compared to the control group, after adjusting for systolic blood pressure (SBP), pulse pressure (PP), and hs-CRP (p=0.005). Among subjects with SVD on MRI, the number of lacunar infarcts (LIs)> or =5 was significantly related to a higher baPWV (p=0.02). The relationship between the severity of periventricular white matter hyperintensities (PWMH) and the degree of baPWV became insignificant after adjustment for age. CONCLUSION: Increased baPWV was significantly associated with the risk of SVD in elderly persons with hypertension. Therefore, the measurement of baPWV could be used to predict SVD.     

Diabetic polyneuropathy,deep white matter lesions,and carotid atherosclerosis: is there any association?

The morphologic and functional damages of diabetes mellitus (DM) on microcirculation can play a role in the pathogenesis of both polyneuropathy and cerebral white matter lesions. The aim of this study is to investigate the relation between polyneuropathy and cerebral deep white matter lesions (DWMLs) and carotid atherosclerosis in patients with type 2 DM. Sixty-six patients with type 2 DM without any disorder that may cause polyneuropathy, and vascular risk factors except for DM and hyperlipidemia were included in the study. DWMLs and carotid atherosclerosis were investigated in patients with and without polyneuropathy. Forty patients (60.6%) had diabetic sensorimotor polyneuropathy. DWMLs were more frequent in patients with polyneuropathy compared to patients without polyneuropathy (p = 0.003). Logistic regression analysis confirmed association between polyneuropathy and DWMLs after adjusted for age (p = 0.013), duration of DM (p = 0.007), and both age and duration of DM (p = 0.016). No statistically significant difference was found between patients with and without polyneuropathy for carotid atherosclerosis. Among patients with polyneuropathy, those having DWMLs had higher mean age (p = 0.003) and longer symptom duration (p = 0.020) compared to patients without DWMLs. No association was found between DWMLs and carotid atherosclerosis. Polyneuropathy and cerebral DWMLs in type 2 DM patients may share common pathogenesis; presence and duration of polyneuropathy symptoms may predict ischemic white matter damage independent of carotid atherosclerosis.     

Elevated plasma homocysteine is associated with increased brain atrophy rates in older subjects with mild hypertension

We determined using serial MR imaging whether raised plasma homocysteine levels are associated with increased brain atrophy, white matter lesion (WML) progression or incidence of silent brain infarcts (SBIs) in older hypertensive subjects. Brain atrophy rates (0.58 ± 0.48% per year, mean ± SD) were significantly correlated with homocysteine (β = 0.46, p = 0.001 homocysteine; β = 0.44, p = 0.007 homocysteine/folate/B12 models) but not with folate or B12 levels. Progression of WML (0.08 ± 0.16%) was not associated with homocysteine level (B = 0.01, p = 0.29). New SBIs were uncommon. In older hypertensive individuals, plasma homocysteine levels are associated with increased rates of whole-brain atrophy but not WML progression.     

Cerebral small vessel disease and C-reactive protein: results of a cross-sectional study in community-based Japanese elderly

BACKGROUND AND PURPOSE: Inflammatory processes are involved in the pathogenesis of atherosclerosis. Inflammation has been known as a risk factor for coronary heart disease, whereas inflammation as a risk for cerebrovascular disease is less well established. Whether inflammatory processes, excluded from their involvement in large-vessel disease, are implicated in the pathogenesis of cerebral small vessel disease remains unclear. We assessed whether higher C-reactive protein (CRP) levels were associated with an increased number of lacunar infarcts or severity of white matter lesions. METHODS AND RESULTS: In a community-based group of Japanese elderly (n=689), CRP concentrations were measured using a highly sensitive assay. All participants underwent magnetic resonance imaging (MRI), and cerebral small vessel disease-related lesions (lacunar infarcts and white matter hyperintensity) were subsequently evaluated. Furthermore, carotid atherosclerosis was also assessed with ultrasonography. As the grades of white matter hyperintensity and the numbers of lacunes were considered small vessel disease-related lesions, we evaluated the relationships between CRP levels and small vessel disease-related brain lesions. Interestingly, the median CRP concentration of our participants was remarkably lower, being approximately one third or one quarter of the value of Western populations. Subjects with higher CRP levels tended to have more small vessel disease-related lesions; however, these associations were not seen after adjustment for cardiovascular risk factors and carotid atherosclerosis. CONCLUSIONS: The relationship between CRP levels and small vessel disease-related lesions was not apparent in the community-based Japanese elderly. The impact of inflammation in the pathogenesis of small vessel disease-related brain lesions seems to be weak among the Japanese elderly.     

Quantitative measures of gait characteristics indicate prevalence of underlying subclinical structural brain abnormalities in high-functioning older adults

Abnormal gait in high-functioning older adults may indicate underlying subtle structural brain abnormalities. We tested the hypothesis that temporal and spatial parameters of gait, including speed, stride length and double support time, are cross-sectionally associated with white matter hyperintensity, subcortical infarcts or brain atrophy on brain MRI. We examined 321 men and women (mean age = 78.3) participating to the Cardiovascular Health Study who were free of dementia or stroke at the time of the gait assessment. Analyses were set with gait as independent variable and brain MRIs as dependent variables. Gait measures were determined from the footfalls recorded on a 4-meter-long instrumented walking surface, the GaitMat II. Brain MRIs were examined for the presence of white matter hyperintensity (WMG, graded from 0 to 9), brain infarcts (predominantly subcortical) and ventricular enlargement (graded from 0 to 9). Slower gait, shorter stride length and longer double support times were associated with greater prevalence of white matter grade > or =3 (p = 0.02), and at least 1 brain infarct (p = 0.04) independent of age. In multivariate logistic regression models adjusted for demographics and clinical cardiovascular diseases, those with gait speed <1.02 m/s were more likely to have WMG > or =3 and at least 1 brain infarct, compared with those with faster gait - odds ratio (OR): 2.85, 95% confidence interval (95% CI): 1.35, 6.02, and OR: 2.09, 95% CI: 1.04, 4.19. Shorter stride length was also associated with greater probability of having at least 1 brain infarct (gait stride <0.88 vs. >1.10 m: OR: 3.20, 95% CI: 1.49, 6.88), while longer double support times were associated with a greater probability of having WMG > or =3 (double support time >0.19 vs. <0.14 s: OR: 2.3, 95% CI: 1.1, 4.7) independent of demographics and clinical cardiovascular diseases. Gait parameters were not significantly associated with ventricular grade. In summary, in this group of high-functioning older adults, poorer gait speed, shorter stride and longer double support time are associated with high white matter disease and subclinical strokes.     

Quantitative MRI findings and cognitive impairment among community dwelling elderly subjects

OBJECTIVES: To study the factors which influence cognitive impairment among elderly subjects living in a local community, based on both MRI and clinical findings, to further elucidate the causes of dementia, and also to help develop strategies for its prevention. METHODS: Cranial MRI and other medical examinations were performed on non-demented elderly subjects who resided in one rural community. A total of 254 subjects aged from 60 to 91 years of age, with a mean age of 73.9 (SD 6.8) were examined. The mini mental state examination (MMSE) was used to identify cognitive impairment. White matter lesions and cerebral atrophy on MR images were measured quantitatively. A multivariate analysis was also performed with the existence of cognitive impairment as the dependent variable, and the MRI findings and clinical observations were used as the independent variables. RESULTS: Cognitive impairment was present in 46 subjects (18.1%). They were older, had a lower educational level, and more frequent hypertension compared with those without cognitive impairment. The packed cell volume was lower in the impaired group. In addition, their MRI findings showed significantly larger quantities of white matter lesions and cerebral atrophy, as well as more infarcts. A logistic regression analysis demonstrated a significant relation among such factors as white matter lesions (odds ratio (OR) 1.575, 95% confidence interval (95% CI) 1.123-2.208), cerebral atrophy (OR 0.761, 95%CI 0.587-0.987), and lower education (OR 0.682, 95%CI 0.544-0.855) for subjects with a cognitive impairment. CONCLUSIONS: White matter lesions and cerebral atrophy are factors which induce a cognitive impairment in community dwelling elderly subjects without dementia. It is important to carefully watch for any abnormalities in these factors, and to perform cohort studies to check for the above risk factors, to both prevent and make an early diagnosis of dementia.     

Neurological abnormalities predict disability: the LADIS (Leukoaraiosis And DISability) study

To investigate the role of neurological abnormalities and magnetic resonance imaging (MRI) lesions in predicting global functional decline in a cohort of initially independent-living elderly subjects. The Leukoaraiosis And DISability (LADIS) Study, involving 11 European centres, was primarily aimed at evaluating age-related white matter changes (ARWMC) as an independent predictor of the transition to disability (according to Instrumental Activities of Daily Living scale) or death in independent elderly subjects that were followed up for 3 years. At baseline, a standardized neurological examination was performed. MRI assessment included age-related white matter changes (ARWMC) grading (mild, moderate, severe according to the Fazekas’ scale), count of lacunar and non-lacunar infarcts, and global atrophy rating. Of the 633 (out of the 639 enrolled) patients with follow-up information (mean age 74.1 ± 5.0 years, 45 % males), 327 (51.7 %) presented at the initial visit with ≥1 neurological abnormality and 242 (38 %) reached the main study outcome. Cox regression analyses, adjusting for MRI features and other determinants of functional decline, showed that the baseline presence of any neurological abnormality independently predicted transition to disability or death [HR (95 % CI) 1.53 (1.01–2.34)]. The hazard increased with increasing number of abnormalities. Among MRI lesions, only ARWMC of severe grade independently predicted disability or death [HR (95 % CI) 2.18 (1.37–3.48)]. In our cohort, presence and number of neurological examination abnormalities predicted global functional decline independent of MRI lesions typical of the aging brain and other determinants of disability in the elderly. Systematically checking for neurological examination abnormalities in older patients may be cost-effective in identifying those at risk of functional decline.     

Relation of cerebral small-vessel disease and brain atrophy to mild Parkinsonism in the elderly.

The association between cerebral small-vessel disease, brain atrophy, and the risk and severity of mild parkinsonian signs (MPS) remains unclear. The objective of this study is to examine the effect of lacunar brain infarcts, cerebral white matter lesions (WMLs), and cortical atrophy on the risk and severity of MPS. This study is a cross-sectional community-based cohort study comprising 268 subjects, 65 to 83 years of age, residing in the Augsburg region of southern Germany, and without contraindications for magnetic resonance imaging (MRI) of the brain. Main outcome measures. Subcortical and periventricular WMLs, lacunar brain infarcts, and cortical atrophy determined using a standardized MRI protocol developed for the Rotterdam Scan Study and an established rating scale. MPS, assessed in a standardized neurological examination and based on the Unified Parkinson's Disease Rating Scale motor scale. Lacunar brain infarcts and large subcortical white matter lesions were associated with an elevated risk of resting tremor. More severe cortical atrophy was related to an increased risk of rigidity and bradykinesia. In a linear regression analysis relating each individual MRI measurement with the severity of MPS, the number of lacunar brain infarcts and the degree of brain atrophy were correlated with the severity of resting tremor, whereas the size of subcortical and periventricular WMLs was correlated with the severity of rigidity. A higher degree of brain atrophy was associated with increased severity of either cardinal sign. In our study, presence and volume of lacunar brain infarcts, cerebral WMLs, and cortical atrophy were associated with the risk as well as severity of MPS. Determining the presence of these brain changes using brain imaging might contribute to identify persons at risk for MPS.     

Atrial fibrillation and the risk of cerebral white matter lesions

BACKGROUND: Cerebral white matter lesions are often observed on MRI scans of elderly nondemented and demented persons. Their pathogenesis is not fully understood but cerebral hypoperfusion may be involved. Atrial fibrillation is a common finding in elderly subjects and may lead to a reduced cardiac output with cerebral hypoperfusion. The authors investigated the association between atrial fibrillation and the presence of white matter lesions. METHODS: From 1995 through 1996, the authors randomly sampled 1077 subjects from two ongoing prospective population-based studies. From each participant, an electrocardiogram (ECG) was recorded; atrial fibrillation and left ventricular hypertrophy were diagnosed with a computer program. For one of the two groups (553 subjects), earlier ECGs were available (mean follow-up 4.7 years). All subjects underwent 1.5-T MRI scanning; white matter lesions were separately rated for the periventricular and subcortical regions. RESULTS: The prevalence of atrial fibrillation was 1.9% among subjects younger than 75 years and 5.5% in subjects older than 75 years. The total number of subjects with atrial fibrillation was 28. Subjects with atrial fibrillation had severe periventricular white matter lesions more than twice as often as subjects who did not (RR 2.2; 95% CI 1.0 to 5.2) but had no increased risk of subcortical white matter lesions (RR 1.1; 95% CI 0.4 to 2.6). For seven subjects with atrial fibrillation both at baseline and at follow up, these relative risks were 6.3 (95% CI 1.1 to 37.1) and 0.7 (95% CI 0.1 to 3.7). CONCLUSIONS: Atrial fibrillation is associated with periventricular white matter lesions, but not with subcortical white matter lesions.     

脑皮质下小血管病变与脑萎缩的相关性分析

目的探讨脑皮质下小血管病变与脑萎缩的相关性。方法通过10例临床确诊为脑萎缩的病人的调查,收集其临床基本资料及头颅磁共振成像(magnetic resonance imaging,MRI)的结果及图像,评判其脑皮质下小血管的病变情况。结果所有病例颅脑MRI均发现显著的弥漫性脑白质病变(white matter lesions,WML)和多发的脑腔隙性梗死灶(lacunarinfarcts,LI)。结论颅脑MRI提示,脑皮质下小血管病变与脑萎缩共存,提供了其与脑萎缩可能有关的临床依据。     

Cerebral lacunae: still under debate]

During the last fifteen years, a new interest has been shown in cerebral lacunes due to the development of brain imagery using Magnetic Resonance Imaging (MRI). The concept of lacunar infarction as defined par Fisher (lacunar hypothesis) can no longer be accepted. Clinical data showed that the so-called lacunar clinical syndromes were far from being specific and could be observed in corticosubcortical infarcts. Epidemiological data pointed out that hypertensive disease was not found in many cases of lacunar infarction. Pathological studies suggest that there are two types of lacunar infarction. Lacunar infarcts resulting in clinical stroke syndromes (type 1 a lacunae) seem to be mainly due to obstruction of the trunk of a perforating artery by atherosclerosis. Silent lacunar infarcts (type 1 b lacunae) result from obstruction of small ramifications of the perforating arteries by a non specific microangiopathy related to age, atherosclerosis, cardiovascular disease as well as to hypertensive disease. Silent lacunar infarcts and dilatation of perivascular spaces (type 3 lacunae) are associated with the white matter hyperintensities shown by MRI in elderly subjects. Lacunar infarcts and diffuse white matter hyperintensities are related to small vessel changes and ischaemic damages resulting from (a) arteriolar occlusion and or (b) loss of autoregulation associated with variations in systemic blood pressure. Both lesions constitute a high risk to develop Vascular Cognitive Impairment (Hachinski) and are frequently associated with Alzheimer's disease. Cases of giant or expanding type 3 lacunae have been reported in the last ten years but the physiopathology of such lacunes and their relationship with clinical symptoms remain a puzzle.