White matter lesions and disequilibrium in older people. II. Clinicopathologic correlation

Association between physical activity measured by accelerometry and cognitive function in older adults: a systematic review

OBJECTIVE

To analyze studies that investigated the association between physical activity assessed by accelerometry and cognitive function in older people.

METHODS

A systematic review was carried out in four electronic databases (PubMed, Web of Science, Scopus, and SportsDiscus).

RESULTS

In total, 195 records were identified. Fifty-two studies were selected for a full evaluation; 23 were selected according to the inclusion criteria adopted and divided into four chapters (characteristics of the studies, the association between physical activity level and cognitive function decline, effects of physical activity in reducing the chances of cognitive function decline and effects of physical activity on brain plasticity. The cross-sectional studies had an average score of 7 points, and the cohort studies obtained 10 points, indicating the high quality of the selected studies. Seven studies indicated an association between Moderate to vigorous physical activities (MVPA) and cognitive function, two specifically indicated a reduction in the chances of cognitive function decline according to the interquartile of MVPA, and three studies indicated improvements in MVPA in brain plasticity.

CONCLUSION

Measured by accelerometry, seems to be favorably associated with important outcomes in cognitive function assessed through questionnaires, imaging analyses, and biochemical markers with older adults.

The Aging Overactive Bladder: A Review of Aging-Related Changes from the Brain to the Bladder

PURPOSE OF REVIEW

To understand the current literature on age-related neural and detrusor changes associated with overactive bladder symptoms.

RECENT FINDINGS

Recent functional magnetic resonance imaging (fMRI) studies have unveiled an age-related decrease in the neural control of continence, represented in the insula, anterior cingulate cortex (ACC) and prefrontal cortex (PFC). Older individuals with overactive bladder symptoms also demonstrate heightened activation of the ACC with low volumes, representing increased bladder sensitivity or sense of urgency. At the level of the bladder, age-related changes in the urothelium, neurotransmitters/receptors (both muscarinic and purinergic), and inflammation [including nerve growth factor (NGF), monocyte chemoattractant protein-1 (MCP-1) and oxidative stress] are also associated with overactive bladder.

SUMMARY

Overactive bladder among older adults is a complex condition incorporating physiologic age-related changes from the brain to the bladder and beyond.

Confirmation of the abnormal lipid metabolism as a risk factor for the disease of leukoaraiosis

Our purpose is to screen out medical history indicators and test indicators linked to lipid metabolism which is closely correlated to leukoaraiosis (LA), and to build assistant diagnosis model based on support vector machine (SVM), which provided theoretical evidence for genesis and development of LA. One thousand LA patients who underwent magnetic resonance imaging (MRI) examination in Imaging Department was retrospectively analyzed and divided into LA group and non-LA group in accordance with examination results. Detailed clinical statistics of the two groups were collected, including test indicators related to lipid metabolism, such as total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), medical history indicators, age, sex, diabetes, hypertension, hyperlipidemia, history of intracranial infection, history of cerebral hemorrhage, cerebral infarction, lacunar infarction and relevant biochemical indexes. The study shows that patients’ incidence of LA was 31.10%; in accordance with Logistic analysis, the incidence of LA is significantly correlated to factors like age, hypertension, history of cerebral hemorrhage, cerebral infarction, lacunar infarction and triglyceride elevation; two SVMs, one including all variables and the other containing all screened variables were successfully established, and the former’s accuracy, specificity and sensitivity respectively were 85.0%, 85.0% and 85.0% while the latter’s 90.0%, 100.0% and 80.0%. Test indicators and medical history indicators of lipid metabolism correlated to LA were screened out successfully. Meanwhile, an effective SVM model also was built successfully, which is able to predict LA relatively accurately and can be used as assistant diagnostic tool for clinicians.

Physical activity and cardiorespiratory fitness are beneficial for white matter in low-fit older adults

Physical activity (PA) and cardiorespiratory fitness (CRF) are associated with better cognitive function in late life, but the neural correlates for these relationships are unclear. To study these correlates, we examined the association of both PA and CRF with measures of white matter (WM) integrity in 88 healthy low-fit adults (age 60–78). Using accelerometry, we objectively measured sedentary behavior, light PA, and moderate to vigorous PA (MV-PA) over a week. We showed that greater MV-PA was related to lower volume of WM lesions. The association between PA and WM microstructural integrity (measured with diffusion tensor imaging) was region-specific: light PA was related to temporal WM, while sedentary behavior was associated with lower integrity in the parahippocampal WM. Our findings highlight that engaging in PA of various intensity in parallel with avoiding sedentariness are important in maintaining WM health in older age, supporting public health recommendations that emphasize the importance of active lifestyle.

Higher-level gait disorders: an open frontier

The term higher-level gait disorders (HLGD) defines a category of balance and gait disorders that are not explained by deficits in strength, tone, sensation, or coordination. HLGD are characterized by various combinations of disequilibrium and impaired locomotion. A plethora of new imaging techniques are beginning to determine the neural circuits that are the basis of these disorders. Although a variety of neurodegenerative and other pathologies can produce HLGD, the most common cause appears to be microvascular disease that causes white-matter lesions and thereby disrupts balance/locomotor circuits.

Is overactive bladder a brain disease? The pathophysiological role of cerebral white matter in the elderly

Small-vessel disease of the brain affecting the deep white matter characteristically manifests with neurological syndromes, such as vascular dementia and vascular parkinsonism. There is, however, compelling evidence to suggest that white matter disease can cause overactive bladder and incontinence, and in some patients these might be the initial manifestation. As white matter disease increases significantly with age, and preferentially affects the prefrontal deep white matter, white matter disease becomes an anatomical substrate in the brain etiology of overactive bladder. Treatment entails the management of small-vessel disease risk factors and anticholinergic drugs that do not easily penetrate the blood-brain barrier, to improve bladder control. In short, when caring for elderly overactive-bladder patients, we should look at both the brain and the bladder.

Investigation of the Risk Factors for Leukoaraiosis (LA)

Leukoaraiosis (LA) describes abnormal changes in the cerebral white matter frequently seen on CT and MRI in older adults. Its appearance indicates mild brain injury, and it is often regarded as a mark of senile dementia. Through the analysis of related risk factors of 6000 patients with LA diagnosed by cranial MRI in our department, we found that age, cerebral infarction, lacunar infarction, history of brain hemorrhage, and increased triglycerides were risk factors for LA, and the relative risk odds ratio values were 2.135 (95% confidence interval [CI] = 1.874-2.501), 3.330 (95% CI = 1.922-3.997), 3.412 (95% CI = 2.986-3.512), 3.611 (95% CI = 2.054-9.147), and 1.457 (95% CI = 1.058-1.769), respectively. Through the identification of the risk factors for LA and effective interventions, the occurrence of dementia, stroke, and premature death may be effectively prevented.

White matter hyperintensity volume and impaired mobility among older adults

Gait speed is associated with multiple adverse outcomes of aging. White matter hyperintensities (WMH) on magnetic resonance imaging (MRI) have been associated with gait speed, though few studies have examined changes in gait speed over time in population-based studies comprising participants from diverse cultural backgrounds. The purpose of this study was to examine the association between a decline in gait speed and total and regional WMH volumes in a community-based study of aging. Participants (n = 701) underwent gait-speed measurement via a 4-m walk test at the time of initial enrollment and MRI at a second time interval (mean 4.7 [SD = 0.5] years apart). Logistic regression was used to examine the association between large WMH volume and regional WMH volume with gait speed <0.5 m/s (abnormal speed), and a transition to abnormal gait speed. Analyses were adjusted for demographic and clinical factors. Large WMH volume was associated with abnormal gait speed and a transition to abnormal gait speed between the two visits, but not after adjustment for modifiable vascular disease risk factors. Increased frontal lobe WMH volume was associated with abnormal gait speed and transition to abnormal gait speed, but not in adjusted models. WMH are associated with slowing of gait over time. Prevention of WMH presents a potential strategy for the prevention of gait speed decline.

Mobility impairment is associated with reduced microstructural integrity of the inferior and superior cerebellar peduncles in elderly with no clinical signs of cerebellar dysfunction

While the cerebellum plays a critical role in motor coordination and control no studies have investigated its involvement in idiopathic mobility impairment in community-dwelling elderly. In this study we tested the hypothesis that structural changes in the cerebellar peduncles not detected by conventional magnetic resonance imaging are associated with reduced mobility performance. The analysis involved eighty-five subjects (age range: 75–90 years) who had no clinical signs of cerebellar dysfunction. Based on the short physical performance battery (SPPB) score, we defined mobility status of the subjects in the study as normal (score 11–12, n = 26), intermediate (score 9–10, n = 27) or impaired (score < 9, n = 32). We acquired diffusion tensor imaging data to obtain indices of white matter integrity: fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). Using a parcellation atlas, regional indices within the superior, middle, and inferior cerebellar peduncles (ICP, MCP, SCP) were calculated and their associations with mobility performance were analyzed. Subjects with impaired mobility showed reduced FA and AD values in the ICP and SCP but not in the MCP. The ICP-FA, ICP-AD and SCP-FA indices showed a significant association with the SPPB score. We also observed significant correlation between ICP-FA and walk time (r = − 0.311, p = 0.004), as well as between SCP-AD and self-paced maximum walking velocity (r = 0.385, p = 0.003) and usual walking velocity (r = 0.400, p = 0.002). In logistic regression analysis ICP-FA and ICP-AD together explained 51% of the variability in the mobility status of a sample comprising the normal and impaired subgroups, and correctly classified more than three-quarters of those subjects. Our findings suggest that presence of microstructural damage, likely axonal, in afferent and efferent connections of the cerebellum contributes to the deterioration of motor performance in older people.

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DTI study of the cerebellar peduncles and mobility in elderly.

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Fractional anisotropy and axial diffusivity of inferior peduncle predict mobility.

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Decreased anisotropy in the peduncles in the absence of T2 lesions.

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Findings likely reflect axonal degeneration of proprioceptive afferent fibers.

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Abnormalities in infratentorial white matter are novel findings in the field.

White matter hyperintensities in Parkinson's disease: do they explain the disparity between the postural instability gait difficulty and tremor dominant subtypes?

Background

Brain white matter hyperintensities (WMHs) commonly observed on brain imaging of older adults are associated with balance and gait impairment and have also been linked to cognitive deficits. Parkinson’s disease (PD) is traditionally sub-classified into the postural instability gait difficulty (PIGD) sub-type, and the tremor dominant (TD) sub-type. Considering the known association between WMHs and axial symptoms like gait disturbances and postural instability, one can hypothesize that WMHs might contribute to the disparate clinical sub-types of patients with PD.

Methods

110 patients with PD underwent a clinical evaluation and a 3T MRI exam. Based on the Unified Parkinson Disease Rating Scale, the patients were classified into motor sub-types, i.e., TD or PIGD, and scores reflecting PIGD and TD symptoms were computed. We compared white matter burden using three previously validated methods: one using a semi-quantitative visual rating scale in specific brain regions and two automated methods.

Results

Overall, MRI data were obtained in 104 patients. The mean WMHs scores and the percent of subjects with lesions in specific brain regions were similar in the two subtypes, p = 0.678. The PIGD and the TD scores did not differ even when comparing patients with a relatively high burden of WMHs to patients with a relatively low burden. Across most of the brain regions, mild to moderate correlations between WMHs and age were found (r = 0.23 to 0.41; p<0.021). Conversely, no significant correlations were found between WMHs and the PIGD score or disease duration. In addition, depressive symptoms and cerebro-vascular risk factors were similar among the two subtypes.

Conclusions

In contrast to what has been reported previously among older adults, the present study could not demonstrate any association between WMHs and the PIGD or TD motor sub-types in patients with PD.

High-level gait disorder: associations with specific white matter changes observed on advanced diffusion imaging

BACKGROUND AND PURPOSE

High-level gait disorder (HLGD) is a debilitating disorder causing mobility decline in the elderly. Although its clinical characteristics are well described, its anatomical and pathophysiological underpinnings are poorly understood. This study examined the anatomical distribution of white matter (WM) changes in patients with mild to moderate HLGD of the cautious/disequilibrium type, using advanced magnetic resonance imaging (MRI) methods.

METHODS

Thirteen patients with HLGD, 9 elderly and 13 middle-aged healthy controls were scanned using diffusion tensor imaging, Q-space imaging, and conventional MRI. The regions of significant differences between the HLGD group and the elderly control group were defined, and the mean fractional anisotropy and displacement values of these areas were extracted.

RESULTS

The HLGD patients had lower fractional anisotropy and higher displacement values in regions related to the motor system, including those along the corticospinal tract and the superior cerebellar peduncles, as well as in cognitive and affective-related areas, including the anterior limbs of the internal capsule and the genu of the corpus callosum.

CONCLUSIONS

The anatomical distribution associated with HLGD of the cautious/disequilibrium type involves WM pathways that convey motor-related, cognitive and affective-related functions. The underlying pathological process leading to these changes most probably includes demyelination.

Vascular incontinence: incontinence in the elderly due to ischemic white matter changes

This review article introduces the new concept of vascular incontinence, a disorder of bladder control resulting from cerebral white matter disease (WMD). The concept is based on the original observation in 1999 of a correlation between the severity of leukoareosis or WMD, urinary symptoms, gait disorder and cognitive impairment. Over the last 20 years, the realization that WMD is not a benign incidental finding in the elderly has become generally accepted and several studies have pointed to an association between geriatric syndromes and this type of pathology. The main brunt of WMD is in the frontal regions, a region recognized to be crucial for bladder control. Other disorders should be excluded, both neurological and urological, such as normal-pressure hydrocephalus, progressive supranuclear palsy, etc., and prostatic hyperplasia, physical stress incontinence, nocturnal polyuria, etc. Treatment involves management of small vessel disease risk factors and anticholinergic drugs that do not easily penetrate the blood brain barrier to improve bladder control.

Mobility decline in the elderly relates to lesion accrual in the splenium of the corpus callosum

In a previous cross-sectional study on baseline data, we demonstrated that the volume of brain white matter hyperintensities (WMH) in the splenium of corpus callosum (SCC) predicted the current mobility function of older persons. The primary aim of this follow-up study was to determine the relation of WMH volume change in SCC (SCC-∆WMH) with change in mobility measures. A secondary aim was to characterize the global and regional progression of WMH. Mobility function and WMH burden were evaluated at baseline and at 2 years in 77 community-dwelling individuals (baseline age, 82 ± 4). Regional WMH in SCC, as well as genu and body of corpus callosum, subregions of corona radiata, and superior longitudinal fasciculus were determined using a white matter parcellation atlas. The total WMH volume increased 3.3 ± 3.5 ml/year, mainly through enlargement. Significant WMH increases were observed in all selected regions, particularly within the corona radiata. While at baseline and follow-up we observed correlations between WMH burden and several measures of mobility, longitudinal change correlated only with change in chair rise (CR). SCC-∆WMH showed the highest correlation (r = -0.413, p = 0.0002) and was the best regional predictor of CR decline (OR = 1.5, r(2) = 0.3). The SCC-∆WMH was more than five times larger in the CR-decline group compared to the no-decline group (p = 0.0003). The SCC-∆WMH (top quartile) showed a higher sensitivity/specificity for CR decline compared to change in total WMH, 63/88% versus 52/84%, respectively. The findings suggest that accrual of WMHs in posterior areas of the brain supporting inter-hemispheric integration and processing of visual-spatial information is a mechanism contributing to age-related mobility deterioration.

Pathology of lacunar ischemic stroke in humans--a systematic review

Twenty-five percent of ischemic strokes are lacunar in type, but the cause remains unclear. Pathological descriptions of lacunar lesions are available but have not been systematically assessed. We therefore systematically summarized studies describing lacunar lesions by extracting data on the number of patients and lesions, clinical details, pathological methods, brain regions and/or vessels examined, and both parenchymal and vascular findings. Among 39 papers describing >4000 lesions (>50% from one study), 15 papers examined patients with a clinical lacunar syndrome. Terminology varied, many studies only reported macroscopic pathology and many lesions were cavitated (ie, old). Aside from symptomatic lesions occurring more often in the internal capsule or caudate nucleus, we found no other differences between symptomatic and asymptomatic patients. Perivascular edema and thickening, inflammation and disintegration of the arteriolar wall were common, whereas vessel occlusion was rare. The causal mechanisms of lacunar stroke remain poorly defined because of methodological inconsistencies and challenges. Standardised pathological definitions based on well-characterized post-mortem derived material supported by detailed clinical and imaging data are needed.

Cerebral microinfarcts: the invisible lesions

The association between small but still visible lacunar infarcts and cognitive decline has been established by population-based radiological and pathological studies. Microscopic examination of brain sections shows even smaller but substantially more numerous microinfarcts, the focus of this Review. These lesions often result from small vessel pathologies such as arteriolosclerosis or cerebral amyloid angiopathy. They typically go undetected in clinical-radiological correlation studies that rely on conventional structural MRI, although the largest acute microinfarcts can be detected by diffusion-weighted imaging. In view of their high numbers and widespread distribution, microinfarcts could directly disrupt important cognitive networks and thus account for some of the neurological dysfunction associated with lesions visible on conventional MRI such as lacunar infarcts and white matter hyperintensities. Standardised neuropathological assessment criteria and the development of non-invasive means of detection during life would be major steps towards understanding the causes and consequences of otherwise macroscopically invisible microinfarcts.

Balance and gait problems in the elderly

Gait and balance problems are common with advancing age. Disorders of balance and gait are particularly important in the elderly because they compromise independence and contribute to the risk of falls and injury. Although they are considered as separate clinical entities, balance and gait disturbance are often intertwined. Here, we discuss the principal anatomical and physiologic mechanisms responsible for balance and gait. We also review the different types of fall patterns commonly seen in subjects and a classification scheme for various gait disorders. Furthermore, we consider the relationship between balance and gait disorders and subcortical vascular disease. Potential interventions and therapies in those individuals with balance and gait disorders are also discussed.

Cortical thickness is linked to executive functioning in adulthood and aging

Executive functions that are dependent upon the frontal-parietal network decline considerably during the course of normal aging. To delineate neuroanatomical correlates of age-related executive impairment, we investigated the relation between cortical thickness and executive functioning in 73 younger (20-32 years) and 56 older (60-71 years) healthy adults. Executive functioning was assessed using the Wisconsin Card Sorting Test (WCST). Cortical thickness was measured at each location of the cortical mantle using surface-based segmentation procedures on high-resolution T1-weighted magnetic resonance images. For regions involved in WCST performance, such as the lateral prefrontal and parietal cortices, we found that thicker cortex was related to higher accuracy. Follow-up ROI-based analyses revealed that these associations were stronger in older than in younger adults. Moreover, among older adults, high and low performers differed in cortical thickness within regions generally linked to WCST performance. Our results indicate that the structural cortical correlates of executive functioning largely overlap with previously identified functional patterns. We conclude that structural preservation of relevant brain regions is associated with higher levels of executive performance in old age, and underscore the need to consider the heterogeneity of brain aging in relation to cognitive functioning.

Differing risk factors and outcomes in ischemic stroke subtypes: focus on lacunar stroke

Lacunar stroke has been a recognized stroke subtype for many years but its pathophysiology remains unknown, so prevention and treatment are suboptimal. Most lacunar strokes result from an intrinsic cerebral small vessel disease, probably part of a systemic disorder. Hypertension, diabetes and other vascular risk factors (but not atrial fibrillation and ipsilateral carotid stenosis) are equally common in lacunar as in large artery atherothromboembolic stroke, which, together with other factors, suggests that the patient’s response to vascular risk factors, not the vascular risk factors per se, determines whether they develop small vessel or large artery stroke. Inflammation and endothelial failure are probably involved in the pathogenesis of lacunar stroke, but their role needs to be clarified. The cerebral venules as well as arterioles are abnormal in this condition. The disorder may not be primarily ischemic; instead, arteriolar thrombosis may be a late-stage phenomenon secondary to chronic arteriolar wall damage resulting from leakage of plasma components across the BBB. Accurate diagnosis of lacunar stroke, avoiding risk factor-based classifications, is required to underpin future research.

Age-related differences in white matter microstructure: region-specific patterns of diffusivity

We collected MRI diffusion tensor imaging data from 80 younger (20-32 years) and 63 older (60-71 years) healthy adults. Tract-based spatial statistics (TBSS) analysis revealed that white matter integrity, as indicated by decreased fractional anisotropy (FA), was disrupted in numerous structures in older compared to younger adults. These regions displayed five distinct region-specific patterns of age-related differences in other diffusivity properties: (1) increases in both radial and mean diffusivity; (2) increases in radial diffusivity; (3) no differences in parameters other than FA; (4) a decrease in axial and an increase in radial diffusivity; and (5) a decrease in axial and mean diffusivity. These patterns suggest different biological underpinnings of age-related decline in FA, such as demyelination, Wallerian degeneration, gliosis, and severe fiber loss, and may represent stages in a cascade of age-related degeneration in white matter microstructure. This first simultaneous description of age-related differences in FA, mean, axial, and radial diffusivity requires histological and functional validation as well as analyses of intermediate age groups and longitudinal samples.

Subjective visual vertical test in patients with chronic dizziness without abnormal findings in routine vestibular function tests

CONCLUSION

The subjective visual vertical (SVV) test can detect abnormality of the otolithic organs and the graviceptive pathways present in a considerable number of patients having dizziness but presenting no abnormal findings in conventional vestibular function tests.

OBJECTIVE

To evaluate whether the SVV test can detect dysfunction of the otolithic organs and perception of gravity in patients with dizziness having no abnormal finding on routine tests for the vestibular system.

PATIENTS AND METHODS

Forty-four patients who complained of chronic dizziness but had no abnormal finding on routine tests for vestibular system and on brain MRI studies were selected between 2004 and 2006. SVV tests were performed on these patients. Patients with chronic dizziness caused by apparent psychogenic disorders, such as depression, were excluded.

RESULTS

Among the 44 patients, 3 showed abnormal tilts of SVV. The latter three patients had deep white matter hyperintensities on their MRI, probably due to aging.

The severity of leukoaraiosis correlates with the clinical phenotype of Parkinson's disease

The impact of leukoaraiosis on Parkinson's disease (PD) has not been completely explained. We evaluated 141 patients with PD to assess the role of leukoaraiosis and determined its influence on the clinical phenotype of PD. Clinical assessments during off medication and leukoaraiosis grading were performed according to the atherosclerosis risk in communities (ARIC) study. Patients were grouped into two phenotypes, tremor or postural instability and gait difficulty (PIGD)-dominant groups. Associations between the age at onset, gender, disease duration, cardiovascular risk factors, leukoaraiosis grade and the disease phenotype were analyzed. In addition, the role of the leukoaraiosis grade in relationship to the parkinsonian motor handicaps was evaluated. The leukoaraiosis correlated with the severity of the clinical symptoms of PD as measured by the United Parkinson's disease rating scale (UPDRS) scores and the Hoehn and Yahr (H + Y) stage. There were significant correlations observed between the leukoaraiosis grade and specific motor handicaps especially those with axial symptoms. Multivariate logistic regression analysis showed that the leukoaraiosis grade was independently associated with the PIGD motor phenotype of PD. The leukoaraiosis grade was independently associated with the PIGD motor phenotype of PD; this might be explained by the affects on nondopaminergic subcortical pathways. These results have implications for clinical management of PD with regard to the control of vascular risk factors.

Gait in ageing and associated dementias; its relationship with cognition

The focus of this review is on the close relationship between gait and cognition in ageing and associated dementias. This close relationship is supported by epidemiological studies, clinical studies of older people with and without dementia that focused on the intensity of the physical activity, clinical studies with older persons without dementia examining a relationship between gait and specific cognitive processes, and human and animal experimental studies examining a neural basis for such a relationship. Despite these findings, most studies with patients with dementia focus exclusively on the relationship between cognition and dementia, with relatively few addressing the relationship between gait and dementia. However, subtle disturbances in gait can be observed in ageing and in (preclinical) subtypes of dementia that are not known for prominent motor disturbances, i.e. Mild Cognitive Impairment, Alzheimer's Disease, vascular Cognitive Impairment No Dementia, Subcortical Ischaemic Vascular Dementia, Frontotemporal Mild Cognitive Impairment, and Frontotemporal Dementia, supporting a close relationship between gait and cognition. The relationship between gait and cognition is weakened by the few available intervention studies that examine the effects of walking on cognition in patients with (preclinical) dementia. These studies report equivocal results, which will be discussed. Finally, suggestions for future research will be made.

Vascular parkinsonism--an update

Vascular parkinsonism (VP) is a heterogeneous clinical entity. The idea of a relationship between cerebral vascular disease and parkinsonism may be traced back to the 1920s, when the diagnostic unit called "arteriosclerotic parkinsonism", a predecessor of VP, was established. This review is concerned with historical and contemporary views regarding the possible vascular genesis of parkinsonism. Confusion persists as a result of vaguely defined diagnostic criteria. The following types of simultaneous occurrence of parkinsonism and cerebral vascular disease (CVD) may be recognised: 1. gait disorders of the lower body parkinsonism type are caused mostly by white matter lesions in the frontal lobes; such disorders may require a diagnosis of vascular origin. We suggest replacing the term "lower body parkinsonism" with a more appropriate term not including the word "parkinsonism": an alternative term could be "cerebrovascular gait disorder"; 2. if the signs and symptoms are typical for idiopathic Parkinson's disease (IPD), the coincidence of IPD and CVD should be considered; 3. if the symptoms of parkinsonism are neither typical for IPD nor for VP, and there are clinical or MR signs of CVD, VP should be regarded as possible when alternative causes are excluded; 4. if the symptoms of parkinsonism and clinical and MR signs are typical for VP, VP should be regarded as probable; 5. if a stroke affecting the contralateral basal ganglia is followed by the occurrence of hemiparkinsonism, the diagnosis of VP is unambiguous. Vascular parkinsonism (VP) is probably one of the most frequently erroneous neurological diagnoses. The reason for this misdiagnosis is that both cerebral vascular disease (CVD) and parkinsonism usually occur at the same age. Due to the high incidence of CVD, it is possible for CVD and idiopathic Parkinson's disease (IPD) to coincide in some cases. Another reason for the misdiagnosis is that the concept of VP lacks clarity. This review aims to contribute to an improved understanding of VP in clinical practice. In this context, the term "CVD" is understood in the broad sense of a brain impairment caused by cerebral vessel pathology. It covers various concepts, as some authors use the term CVD to mean a manifestation of vascular lesions in pathologico-anatomical material or in the imaging techniques; others mean the history and clinical manifestation of cerebral ischaemia, or, more rarely, haemorrhage. The term CVD may cover large vessel disease as well as small vessel disease. This means that territorial and lacunar infarcts and white matter lesions (WML) are all considered as CVD.

Cerebral White Matter Hyperintensities on MRI: Current Concepts and Therapeutic Implications

BACKGROUND

White matter hyperintensities (WMH) are commonly observed MRI abnormalities in the elderly, which generally reflect covert vascular brain injury. WMH cumulatively produce substantial neurologic, psychiatric, and medical morbidity. This review provides an overview of current knowledge on vascular WMH, and describes some pharmacological agents that may have a role in mitigating this condition.

SUMMARY OF REVIEW

This review has two main focus areas. The first is a discussion of currently available knowledge regarding the public health burden, pathogenesis, and various risk factors associated with the presence of vascular white matter lesions noted on brain MRI. The second section of the article details the mechanistic and clinical basis for promising pharmacological treatment modalities that could potentially prevent progression of ischemic cerebral white matter brain injury. Many of these therapies are already of proven efficacy in preventing recurrent stroke.

CONCLUSIONS

Individuals with vascular white matter lesions on MRI may represent a potential target population likely to benefit from secondary stroke prevention therapies.

The effect of vascular disease on late onset Parkinson's disease

The clinical severity of late onset Parkinson's disease (PD) varies from patient to patient and it is further complicated by the increasing prevalence of accompanying disorders in the elderly. We set out to study the impact of ischemic heart disease, minor stroke, hypertension and diabetes mellitus in a group of late onset PD patients (age >or=70 years). Consecutive late onset PD patients seen in the Department of Neurology, Medical School of Patras, Greece were included in this study. We used very strict criteria to eliminate the possibility of including patients with vascular parkinsonism. Comparisons were made between groups of patients suffering with idiopathic Parkinson's disease (IPD) and the above-mentioned diseases. One hundred and sixty-seven consecutive late onset PD patients were included in this study. The most common accompanying disorders in our group were hypertension in 31 (18%) of the patients and minor stroke in 20 (12%). The Hoen and Yahr score in late onset IPD patients who suffered from minor stroke, ischemic heart disease or diabetes mellitus was significantly higher when compared with patients without the above disorders. The results clearly suggest that the presence of vascular disease on an IPD patient may aggravate PD severity. In clinical grounds, these findings can be proved significant since early and aggressive prevention of vascular disease and treatment of vascular risk may contribute in controlling symptom severity in PD.

Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure

The National High Blood Pressure Education Program presents the complete Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Like its predecessors, the purpose is to provide an evidence-based approach to the prevention and management of hypertension. The key messages of this report are these: in those older than age 50, systolic blood pressure (BP) of greater than 140 mm Hg is a more important cardiovascular disease (CVD) risk factor than diastolic BP; beginning at 115/75 mm Hg, CVD risk doubles for each increment of 20/10 mm Hg; those who are normotensive at 55 years of age will have a 90% lifetime risk of developing hypertension; prehypertensive individuals (systolic BP 120-139 mm Hg or diastolic BP 80-89 mm Hg) require health-promoting lifestyle modifications to prevent the progressive rise in blood pressure and CVD; for uncomplicated hypertension, thiazide diuretic should be used in drug treatment for most, either alone or combined with drugs from other classes; this report delineates specific high-risk conditions that are compelling indications for the use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers); two or more antihypertensive medications will be required to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg) for patients with diabetes and chronic kidney disease; for patients whose BP is more than 20 mm Hg above the systolic BP goal or more than 10 mm Hg above the diastolic BP goal, initiation of therapy using two agents, one of which usually will be a thiazide diuretic, should be considered; regardless of therapy or care, hypertension will be controlled only if patients are motivated to stay on their treatment plan. Positive experiences, trust in the clinician, and empathy improve patient motivation and satisfaction. This report serves as a guide, and the committee continues to recognize that the responsible physician's judgment remains paramount.

Emergence and progress of white matter lesion in brain check-up

White matter lesion (WML) is thought to emerge and progress with increasing age but has not yet been well investigated. In this study of WML, risk factors and prevalence added to emergence rate (%/person year) and progress speed [increase of leukoencephalopathy score (LES)/person year] were investigated in 1674 brain check-up subjects from August 1993 to August 2001. Significant (P < 0.01) risk factors were aging and hypertension. Prevalence rate (%) was 0 in 20-29 years, 1.4 in 30-39 years, 4.2 in 40-49 years, 20.9 in 50-59 years, 42.6 in 60-69 years, and 73.9 in 70-years. Emergence rate was 0 in 20-29 years, 0.7 in 30-39 years, 1.5 in 40-49 years, 3.4 in 50-59 years, 6.0 in 60-69 years, and 20 in 70-years. And progress speed was 0.12 in 40-49 years, 0.15 in 50-59 years, 0.21 in 60-69 years, and 0.21 in 70-years. WML begins to emerge early in middle age and both prevalence and severity increase with age.

Cortical functional abnormality assessed by auditory-evoked magnetic fields and therapeutic approach in patients with chronic dizziness

A long-lasting dizzy sensation is a common complaint in elderly subjects. The pathogenesis and effective treatment of such chronic dizziness (CD), however, have not yet been fully elucidated because of lack of methods for evaluating this sensation. On the basis of assumption that CD may be attributable partly to cortical functional abnormality, we attempted to estimate the function of auditory cortex by measurements of auditory-evoked magnetic fields (AEFs). Magnetic field signals in the parieto-temporal cortex were evoked by 1000-Hz tone-burst with 90-dB normal hearing level sounds, and the highest-amplitude magnetic waveforms at approximately 100-ms (N100m) were analyzed as electrical current arrows in normal subjects (n=11), patients with CD (n=27) and patients with cerebral infarction but no dizzy sensation (n=9). In the normal subjects, the current arrows pointed to a nearly straight line with small directional distortion as indicated by a rotation-degree parameter, dI(rot) of 1.59+/-0.46. In 17 of 27 CD patients, the directions of current arrows were markedly distorted showing abnormally high dI(rot) values greater than 2.50 (the mean plus two standard deviations of normal values) and disclosed a clockwise or counter-clockwise rotation in either side or both sides of parieto-temporal cortex. In all the patients with cerebral infarction, the current arrows exhibited the similar pattern as the normal subjects. None of them exhibited abnormally high dI(rot) values. We hypothesized that the rotational abnormality may be caused by abnormal neuronal excitation, since non-evoked magnetic fields in temporal lobe epilepsy demonstrated the similar current rotational abnormality as reported previously. Seven CD patients were treated with anticonvulsants, and four showed remarkable amelioration of dizzy sensation. In all the four patients with symptomatic amelioration, the disappearance of rotational abnormality in AEFs or the tendency towards disappearance was observed following symptomatic amelioration. The results of the present study suggest that the auditory center may contribute to the maintenance of equilibrium, and its dysfunction may lead to the development of CD. AEFs measurements may make it possible to evaluate the functional abnormality of auditory center and may be useful for studying the pathophysiology and treatment of CD.

Magnetic resonance imaging in dementia. A study of brain white matter changes

Non-specific white matter changes (WMC) in the brain are common findings in the elderly population. Although they are frequently seen in non-demented persons, WMC seem to be more common in demented patients. The significance of these changes, as well as their pathophysiological background, is incompletely understood. The aim of this thesis was to study different aspects of WMC using MR imaging (MRI) and to investigate the clinical significance of such changes in subjects with mild cognitive impairment or dementia. In study I post-mortem MRI of the brain was compared to corresponding neuropathology slices. WMC were quantified and found to be more extensive on neuropathology. The areas that appeared normal on MRI but not on histopathology represented only minor changes with increased distance between the myelinated fibres but with preserved axonal network and glial cell density. Study II evaluated the blood-brain barrier (BBB) integrity to investigate if an increased permeability could be shown in WMC. A contrast-enhanced MRI technique was used to detect small degrees of enhancement. No general increase in BBB could be detected in the WMC areas. In study III the relation between WMC and apolipoprotein E (APOE) genotype was explored in patients with Alzheimer's disease (AD). Results showed that AD patients, who were homozygous for the APOE epsilon 4 allele had more WMC than patients with other genotypes. This was most significant for changes in the deep white matter. Results also indicated that in AD patients carrying the epsilon 4 allele, WMC are not age-related phenomena, but might be related to the aetiology of the disease. Study IV aimed to investigate if WMC in a specific brain region affect cognitive functions related to that area. Periventricular WMC in the left frontal lobe predicted a decrease in initial word fluency, a test though to reflect left frontal lobe functioning. This indicates that WMC might have specific effects in different brain regions. In study V we evaluated the prognostic significance of WMC in patients with memory impairment, regarding the rate of further global cognitive decline. There was no difference in outcome between patients having extensive WMC and a matched control group, during 2-4 years of follow up, and assessed by the "Mini-Mental State Examination". In conclusion, this work has shown and characterised pathological changes in the white matter not visible on conventional MRI. We have also shown that there is no major general increase in BBB permeability in areas of WMC. In addition, homozygosity with regard to the APOE epsilon 4 gene allele implies an increased extent of WMC in AD patients. In AD patients carrying this gene allele, WMC are not merely age-related phenomena, but might be related to the aetiology of the disease. We also claim that WMC in a specific location might impair cognitive functions that rely on those specific pathways. In contrast, WMC do not seem to have any prognostic value in predicting the rate of global cognitive decline in patients at a memory clinic.

Equivalent disruption of regional white matter microstructure in ageing healthy men and women

Diffusion tensor imaging was used to measure regional differences in brain white matter microstructure (intravoxel coherence) and macrostructure (intervoxel coherence) and age-related differences between men and women. Neuropsychiatrically healthy men and women, spanning the adult age range, showed the same pattern of variation in regional white matter coherence. The greatest coherence measured was in corpus callosum, where commissural fibers have one primary orientation, lower in the centrum semiovale, where fibers cross from multiple axes, and lowest in pericallosal areas, where fibers weave and interstitial fluid commonly pools. Age-related declines in intravoxel coherence was equally strong and strikingly similar in men and women, with evidence for greater age-dependent deterioration in frontal than parietal regions. Degree of regional white matter coherence correlated with gait, balance, and interhemispheric transfer test scores.

Distinguishing and treating causes of central vertigo

A patient's dizziness can be caused by a peripheral vestibular disorder, VIIIth nerve compression, brain stem ischemia, or cerebellar stroke. Clues from the history and physical examination are mentioned, and diagnostic entities, such as demyelination, cerebrovascular disease, migraine, Arnold-Chiari malformation, cerebellar degeneration, and neoplastic disease are discussed. Treatment options are outlined so that therapeutic and diagnostic trials can be initiated. Guidelines are offered for when to image the brain or posterior circulation vasculature and when a patient with acute vertigo should be admitted for observation.

Depression in late life: psychiatric-medical comorbidity

The links between late-life depression and the medical comorbidities that are often associated with it can be divided into two paths. The path from medical illness to depression reflects general mechanisms related to stress, disability, and loss, as well as more specific physiological mechanisms, including those related to subclinical cerebrovascular disease, adverse drug effects, and endocrine/metabolic effects. Similarly the path from depression to medical illness includes general mechanisms related to self-neglect, decreased adherence to medical treatments, maladaptive health-related behaviors, and, possibly, more specific physiological mechanisms including those related to altered endocrine and autonomic functions, in the clinical context, these two paths can interact to constitute a vicious cycle. With further research, it should be possible to translate current understanding in these areas into advances in both basic knowledge and treatments that could initiate virtuous cycles with beneficial effects for both menial and physical health.

Characterization of cytokine production, screening of lymphocyte subset patterns and in vitro apoptosis in healthy and Alzheimer's Disease (AD) individuals

In order to investigate the possibility of whether or not the lymphocytes of patients with Alzheimer's Disease (AD) are in an activated state, blood mononuclear cells from 45 AD patients and 45 healthy age matched controls were immunophenotyped by measuring the expression of CD3, CD4, CD7, CD8, CD25, CD28, CD56 and HLA-DR by flow cytometry. Circulating and in-vitro-produced cytokines were also measured by ELISA tests. CD7 and CD8 were significantly decreased in AD patients (48.3% and 18.2%, respectively) when compared to healthy subjects (63.2% and 28.3%, respectively). A significant increase in the CD4, CD25 and CD28 antigen expression was also observed in the AD group (55.3% 24.8% and 65.1%) with respect to healthy subjects (44.5%, 10.3% and 54.3%). In addition there was a significant difference in the extent of apoptosis in lymphocyte culture, as measured by mean fluorescence intensity (MFI) of Fas antigen (CD95) expression on CD4+ T cells in 6 AD patients (MFI = 36% and 43%, by anti-CD3 and hyperthermia mediated-apoptosis, respectively) with respect to 6 healthy individuals (MFI = 24% and 31%, by anti-CD3 and hyperthermia mediated-apoptosis, respectively), as well as in T-cell proliferation assay. A decline of Fas antigen expression on CD8+ subset was observed in the AD group with both stimuli (19% and 28%) comparing to the control group (29% and 39%). No differences were observed on circulating cytokines and spontaneous in vitro production of proinflammatory interleukin 1beta (IL-1beta), Tumor Necrosis Factor-alpha (TNF-alpha), IL-6 and IL-10 cytokines. Lipopolysaccharide (LPS)-stimulated in vitro production of IL-1beta, TNF-alpha, IL-6 and IL-10 measured by a whole blood culture system was significantly higher in AD patients comparing to controls. Furthermore, the observed differences were more evident at late stages of disease. These findings suggest that immunological tests, based on lymphocyte immunophenotyping combined with pro-inflammatory cytokine determinations and measurement of apoptosis in peripheral blood might represent a useful tool to obtain more insight into the pathogenesis of AD and into the level of immune activation which could characterize the pathological state of lymphocytes from individual AD patients.

Age-related brain changes associated with motor function in healthy older people

OBJECTIVE

To identify the MRI imaging findings associated with motor changes in healthy older people.

DESIGN

A cross-sectional study.

SETTING

A study of neurologic function in very healthy older people, the Oregon Brain Aging Study.

PARTICIPANTS

Clinical and MRI data were examined in 50 very healthy older subjects (mean age = 85.1, SD = 7.2 years).

MEASUREMENTS

Clinical measures (finger tapping, hand opening and closing, steps and time to walk 30 feet and timed standing on one foot) were dependent variables in multiple regression analyses using age and the following MRI measures as independent variables: total brain volume (TBV)/intracranial volume; ventricular volume/TBV; periventricular high signal/TBV; deep high signal/TBV.

RESULTS

The number of steps and the time to walk 30 feet were each associated with periventricular high signal (steps: r = .58, P < .001; time: r = .60, P < .001) and ventricular volume (steps: r = .54, P < .001; time: r = .58, P < .001). These associations remained significant after adjusting for age. None of the other clinical variables was associated with the MRI volumes.

CONCLUSIONS

Gait measures were associated significantly with periventricular high signal and ventricular volume. These CNS changes contribute to the cause of these important markers of aging.

Neurological and neuroradiological findings in long-term survivors of allogeneic bone marrow transplantation

The aim of this study was to assess neurological, neuropsychological, and neuroradiological findings in long-term survivors of allogeneic bone marrow transplantation (BMT) who were recruited from a hematological outpatient clinic. In addition, risk factors for the development of late neurological complications were identified. In contrast to previous studies on autopsied patients, our study design provoked a bias away from increased neurological sequelae, because patients with early complications after BMT were excluded. Fifty-nine allogeneic patients and 7 autologous BMT patients underwent clinical examination, short neuropsychological testing, and cranial magnetic resonance imaging (MRI) 34 +/- 26 months after BMT. The pathological results of the neurological examination (abnormal 64%) and the MRI examination (white matter lesions, 54%; atrophy, 11%) were associated with the occurrence of chronic graft-versus-host disease (GvHD) evolving from acute GvHD, with corticosteroid therapy and with cyclosporine medication. Neuropsychological impairment (cognitive deficits, 37%) was associated with long-term cyclosporine medication and age. No influence of pre-BMT disease, BMT donor status, or the conditioning regimen was found. These results suggest that the frequent neurological abnormalities in long-term survivors of allogeneic BMT are associated with chronic GvHD and with the resulting immunosuppression as major risk factors.

Gait disorder and parkinsonian signs in patients with stroke related to small deep infarcts and white matter lesions

Vascular parkinsonism is thought to be a distinct parkinsonian syndrome associated with small deep infarcts and white matter lesions (WMLs). We studied the prevalence of parkinsonian features (bradykinesia, rigidity, tremor, and gait disorder) in relation to small deep or territorial infarcts and WMLs on computed tomography (CT) in 62 lacunar and 41 territorial stroke patients, at 3.0 (median) years of follow up. One or more parkinsonian signs were found in 36% of these patients; 11% clinically had parkinsonism. Parkinsonian signs were found more frequently in lacunar than in territorial stroke patients: bradykinesia in 45% and 7%, rigidity in 13% and 7%, tremor in 6% and 7%, and gait disorder in 16% and 7%, respectively. Patients with WMLs at study entry (n = 16) were compared with those without WMLs (n = 87): 56% and 25% had bradykinesia, 25% and 8% rigidity, 25% and 3% tremor, and 38% and 8% gait disorder, respectively. Regression analysis with adjusted odds ratios ([a]OR) showed that WMLs at study entry were associated with bradykinesia ([a]OR 8.0, 95% confidence interval [CI] 1.6-41.6), gait disorder ([a]OR 7.1, 95% CI 1.5-33.7), and tremor ([a]OR 7.0, 95% CI 1.2-40.3). Bradykinesia was associated with lacunar stroke at study entry ([a]OR 11.5, 95% CI 2.4-54.9). Thus, one third of our stroke patients had one or more parkinsonian signs, and 10% clinically had a parkinsonian syndrome that differed from Lewy body parkinsonism: infrequent resting tremor, but frequent gait disorder. Parkinsonian signs were associated with WMLs and lacunar stroke. Therefore, this study favors a distinct vascular parkinsonian syndrome.

The association of antihypertensive agents with MRI white matter findings and with Modified Mini-Mental State Examination in older adults

OBJECTIVES

To examine the association of antihypertensive regimen with magnetic resonance imaging (MRI) white matter hyperintensity and with cognitive impairment in older adults.

DESIGN

Cross-sectional study.

SETTING

The Cardiovascular Health study, an observational prospective cohort study of risk factors for coronary heart disease and stroke in men and women 65 years of age and older.

PARTICIPANTS

1268 men and women with pharmacologically treated hypertension.

MEASUREMENTS

Information on medication use, medical history, and health habits was collected at clinic examinations. Participants completed the Modified Mini-Mental State Examination (3MS) and underwent MRI examination. Without clinical information, study neuroradiologists assigned an overall grade of white matter signal intensity on MRI on a scale from 0 (no findings) to 9 (extensive findings).

RESULTS

Adjusted mean white matter grade was higher for users of calcium channel blockers (2.59, P = .007) and users of loop diuretics (2.60, P = .015) than for users of beta blockers (2.12). The association was present for both dihydropyridine and non-dihydropyridine calcium channel blockers. Adjusted mean 3MS scores were lower for users of calcium channel blockers (89.6, P < .002), especially dihydropyridines, and users of loop diuretics (89.7, P < .006) than for users of beta blockers (92.3). No statistically significant association could be shown for users of other drug regimens, including thiazides and ACE inhibitors.

CONCLUSION

In this study, users of antihypertensive regimens which included calcium channel blockers or loop diuretics had more severe white matter hyperintensity on MRI and worse performance on 3MS than users of beta blockers.

Effect of extracranial carotid artery stenosis and other risk factors for stroke on periventricular hyperintensity

BACKGROUND AND PURPOSE

The pathogenesis of periventricular hyperintensity (PVH) is still uncertain. We investigated the relationship between PVH and risk factors for cerebrovascular diseases, especially extracranial carotid artery stenosis (ECAS).

METHODS

We studied PVH and ECAS in 323 subjects between 1991 and 1994. Using 1.5-T MRI scan images, we measured PVH quantitatively at eight points and evaluated cerebral infarction. Duplex carotid sonography was performed on the carotid arteries bilaterally and used to divide the severity of ECAS into five grades. Risk factors for cerebrovascular diseases and atherosclerotic complications were assessed from the clinical history.

RESULTS

Age was significantly correlated with the size of frontal and whole PVH (P < .01). Frontal PVH was significantly more severe in subjects with hypertension (P < .05). Frontal, occipital, and whole PVH were significantly more severe in subjects with a history of cerebrovascular accident (P < .01). Other risk factors and atherosclerotic complications were not correlated with PVH. There were no significant differences in the severity of PVH among the five groups of ECAS. The severity of PVH in each region was not related to ECAS. There was no significant difference in the age of patients in relation to the five grades of ECAS. However, PVH was significantly more severe in subjects with lacunar infarction or infarction of the deep border zone (P < .05). There was no relationship between PVH and cortical infarction or infarction of the cortical border zone.

CONCLUSIONS

PVH correlated with age, hypertension, and past history of cerebrovascular disease but not with ECAS. PVH was significantly more severe in lacunar infarction and infarction of the deep border zone. These results suggest that small-vessel disease may underlie the pathogenesis and development of PVH.

Pathogenesis of leukoaraiosis: a review

BACKGROUND

Changes in the cerebral hemispheric white matter, detectable with increasing frequency by modern neuroimaging methods, are associated with aging and conceivably may contribute to the development of specific cognitive deficits. The pathogenesis of these cerebral white matter abnormalities (sometimes described as leukoaraiosis) is unknown. This review evaluates the available evidence in support of the hypothesis that the etiology of leukoaraiosis is related to a specific type of cerebral ischemia and highlights mechanisms by which ischemic injury to the brain may induce selected structural alterations limited to the cerebral white matter.

SUMMARY OF REVIEW

The review is based on the critical analysis of over 100 publications (most appearing in the last decade) dealing with the anatomy and physiology of the arterial circulation to the cerebral white matter and with the pathogenesis of leukoaraiosis.

CONCLUSIONS

A significant number of clues support the hypothesis that some types of leukoaraiosis may be the result of ischemic injury to the brain. Structural changes affecting the small intraparenchymal cerebral arteries and arterioles that are associated with aging and with stroke risk factors, altered cerebral blood flow autoregulation, and the conditions created by the unique arterial blood supply of the hemispheric white matter each seem to contribute to the development of leukoaraiosis. To the best of our ability to interpret current information, the type of ischemic injury that is most likely responsible for these white matter changes involves transient repeated events characterized by moderate drops in regional cerebral blood flow that induce an incomplete form of infarction. This hypothesis could be tested in appropriate experimental models.

Clinical correlates of white matter findings on cranial magnetic resonance imaging of 3301 elderly people. The Cardiovascular Health Study

BACKGROUND AND PURPOSE

Our aim was to identify potential risk factors for and clinical manifestations of white matter findings on cranial MRI in elderly people.

METHODS

Medicare eligibility lists were used to obtain a representative sample of 5888 community-dwelling people aged 65 years or older. Correlates of white matter findings were sought among 3301 participants who underwent MRI scanning and denied a history of stroke or transient ischemic attack. Participants underwent extensive standardized evaluations at baseline and on follow-up, including standard questionnaires, physical examination, multiple blood tests, electrocardiogram, pulmonary function tests, carotid sonography, and M-mode echocardiography. Neuroradiologists graded white matter findings from 0 (none) to 9 (maximal) without clinical information.

RESULTS

Many potential risk factors were related to the white matter grade, but in the multivariate model the factors significantly (all P < .01) and independently associated with increased grade were greater age, clinically silent stroke on MRI, higher systolic blood pressure, lower forced expiratory volume in 1 second (FEV1), and income less than $50,000 per year. If excluded, FEV1 was replaced in the model by female sex, history of smoking, and history of physician-diagnosed hypertension at the baseline examination. Many clinical features were correlated with the white matter grade, especially those indicating impaired cognitive and lower extremity function.

CONCLUSIONS

White matter findings were significantly associated with age, silent stroke, hypertension, FEV1, and income. The white matter findings may not be considered benign because they are associated with impaired cognitive and lower extremity function.