Are white matter lesions directly associated with cognitive impairment in patients with lacunar infarcts?

The importance of comorbidities in ischemic stroke: Impact of hypertension on the cerebral circulation

Comorbidities are a hallmark of stroke that both increase the incidence of stroke and worsen outcome. Hypertension is prevalent in the stroke population and the most important modifiable risk factor for stroke. Hypertensive disorders promote stroke through increased shear stress, endothelial dysfunction, and large artery stiffness that transmits pulsatile flow to the cerebral microcirculation. Hypertension also promotes cerebral small vessel disease through several mechanisms, including hypoperfusion, diminished autoregulatory capacity and localized increase in blood-brain barrier permeability. Preeclampsia, a hypertensive disorder of pregnancy, also increases the risk of stroke 4-5-fold compared to normal pregnancy that predisposes women to early-onset cognitive impairment. In this review, we highlight how comorbidities and concomitant disorders are not only risk factors for ischemic stroke, but alter the response to acute ischemia. We focus on hypertension as a comorbidity and its effects on the cerebral circulation that alters the pathophysiology of ischemic stroke and should be considered in guiding future therapeutic strategies.

The concept of sporadic cerebral small vessel disease: A road map on key definitions and current concepts

Sporadic cerebral small vessel disease is considered to be among the most common known neuropathological processes and has an important role in stroke, cognitive impairment, and functional loss in elderly persons. The term is now commonly used to describe a range of neuroimaging, neuropathological, and associated clinical features, the pathogenesis of which is largely unclear but that are thought to arise from disease affecting the perforating cerebral arterioles, capillaries, and venules. Modern neuroimaging has revolutionized our understanding of the consequences of small vessels disease on the brain parenchyma, even though small arteries, arterioles, capillaries, and venules are difficult to be directly visualized with current techniques used in clinical practice. In this short review, we focus on histopathological and neuroimaging perspectives, basic definitions, and recent advances in the field.

Association between Exposure to the Chinese Famine in Different Stages of Early Life and Decline in Cognitive Functioning in Adulthood

Objective: To investigate whether exposure to the Chinese Famine in different life stages of early life is associated with cognitive functioning decline in adulthood.

Methods: We recruited 1366 adults born between 1950 and 1964 and divided them into fetal-exposed, early childhood-exposed (1–3 years old during the famine), mid childhood-exposed (4–6 years old during the famine), late childhood-exposed (7–9 years old during the famine), and non-exposed groups. A selection of cognitive tests was administered to assess their cognitive performance. Association between malnutrition in different famine exposure periods and adult cognitive performance was estimated by multivariate logistic and multiple linear regression analyses.

Results: There were significant differences in cognitive performance between subjects exposed to famine during different life stages. For the general cognitive tests, fetal-exposed period was associated with decreased scores of the Mini-Mental State Examination (MMSE), and late childhood-exposed with decreased scores of the Montreal Cognitive Assessment (MoCA). We also found exposure to famine during mid and late childhood was associated with worse performance on the Stroop color and word test.

Conclusion: Famine exposure in utero and during childhood is associated with overall and specific cognitive decline, affecting selective attention and response inhibition particularly.

Current pathophysiological concepts in cerebral small vessel disease

The association between cerebral small vessel disease (SVD) - in the form of white matter lesions, infarctions, and hemorrhages - with vascular cognitive impairment (VCI), has mostly been deduced from observational studies. Pathological conditions affecting the small vessels of the brain and leading to SVD have suggested plausible molecular mechanisms involved in vascular damage and their impact on brain function. However, much still needs to be clarified in understanding the pathophysiology of VCI, the role of neurodegenerative processes such as Alzheimer's disease, and the impact of aging itself. In addition, both genetic predispositions and environmental exposures may potentiate the development of SVD and interact with normal aging to impact cognitive function and require further study. Advances in technology, in the analysis of genetic and epigenetic data, neuroimaging such as magnetic resonance imaging, and new biomarkers will help to clarify the complex factors leading to SVD and the expression of VCI.

Early determinants of mental health

Environmental adversities in pre- and early postnatal life may have life-long consequences. Based upon a series of epidemiological and clinical studies and natural experiments, this review describes how the early life environment may affect psychological functions and mental disorders later in life. We focus on studies that have examined the associations of small body size at birth and prematurity as proxies of prenatal environmental adversity. We also review literature on materno-fetal malnutrition, maternal prenatal glycyrrhizin in licorice consumption and hypertension-spectrum pregnancy disorders as factors that may compromise the fetal developmental milieu and hence provide insight into some of the mechanisms that may underlie prenatal programming. While effects of programming mostly take place during the first 1000 days after conception, we finally present evidence from prospective studies suggesting that programming can occur also during later critical periods of development or 'windows of plasticity'. The studies may bear relevance for future prevention and intervention programs targeting the potentially modifiable environmental factors that will aid at promoting mental well-being and health of an individual.

Cerebral microbleeds and cognition in cerebrovascular disease: an update

Sporadic cerebral small vessel disease is a major cause of cognitive impairment. MRI is an important tool for detecting and mapping cerebral small vessel disease in vivo. Lacunes and white matter changes are recognized as characteristic MRI manifestations of small vessel disease. Cerebral microbleeds (CMBs) - small, perivascular haemorrhages seen as well-demarcated, hypointense, rounded lesions on MRI sequences sensitive to magnetic susceptibility - are a more recently recognized MRI marker of small vessel pathology. CMBs are increasingly found in various patient populations and disease settings, including first-ever and recurrent ischaemic or haemorrhagic stroke, Alzheimer's disease, vascular cognitive impairment and healthy elderly individuals. Increasing evidence suggests that the anatomical distribution of CMBs (lobar or deep) may have diagnostic value in detecting small vessel disease subtypes including hypertensive arteriopathy and cerebral amyloid angiopathy. However, the relevance of CMBs for cognitive impairment remains uncertain. The study of CMBs and cognition in populations with cerebrovascular disease presents a special challenge as they coexist and correlate with other cerebrovascular pathologies. This review updates current thinking on how CMBs may be relevant in the study of cognitive impairment in populations with cerebrovascular disease, and how they can contribute in understanding the links between cerebrovascular and degenerative pathologies.

A schizophrenia risk gene, ZNF804A, influences neuroanatomical and neurocognitive phenotypes

ZNF804A is one of the strongest candidate genes for schizophrenia (SZ), yet its function and role in disease pathophysiology are largely unknown. The only in vivo endophenotype study of the SZ-associated SNP (rs1344706) pointed towards effects on brain functional connectivity. We examined the relationship of this SNP to neuroanatomical and neurocognitive phenotypes that were assessed in healthy individuals. Volunteers with no history of psychiatric illness were assessed with structural magnetic resonance imaging (1.5T GE scanner, standard gradient-echo acquisition). Carriers of the minor allele were compared with homozygotes for the T (SZ-associated) allele on measures of total volume of the white matter (WM), gray matter (GM), and cerebrospinal fluid compartments, as well as on voxel-wise measurements of regional brain volumes. After examining the correlation between genotype-associated regions of interest and neurocognitive performance measures, the effects of rs1344706 genotype on a measure of visuomotor performance speed (trails A) were examined in an independent cohort of volunteers. Among healthy subjects, risk allele homozygotes showed larger total WM volumes than carriers of the other allele. Controlling for WM volumes, these same subjects showed reduced GM volumes in several regions comprising the 'default mode network,' including angular gyrus, parahippocampal gyrus, posterior cingulate, and medial orbitofrontal gyrus/gyrus rectus (FDR-corrected p<0.05). The risk allele dosage also predicted impairments on a timed visuomotor performance task (trails A). Results support a role of ZNF804A in phenotypes reflecting altered neural connectivity.

Cerebral microbleeds and vascular cognitive impairment

MRI manifestations of small vessel diseases including white matter hyperintensities and lacunes have been recognized as potential substrates of vascular cognitive impairment for many years. Cerebral microbleeds (CMBs)--small, perviascular haemorrhages seen as small, well-demarcated, hypointense, rounded lesions on MRI sequences sensitive to magnetic susceptibility effects--are also now recognized as an imaging marker for small vessel pathology, but their clinical impact on cognition remains uncertain. CMBs are present in about a third of patients with ischaemic stroke, and in a high proportion of patients with Alzheimer's disease, cerebral amyloid angiopathy, and vascular dementia. They have also been increasingly found in normal elderly populations, particularly using sequences optimized for their detection. Some recent studies have suggested an effect of CMBs on cognition, which could relate directly to focal damage to or dysfunction of adjacent brain tissues; alternatively, CMBs may be a more general marker for the severity of small vessel pathology related to hypertension or cerebral amyloid angiopathy. CMBs may therefore play a role in understanding the underlying mechanisms of vascular cognitive impairment, in diagnosis, and in assessing its severity and prognosis; this review considers recent evidence on this topic.

Prenatal undernutrition and cognitive function in late adulthood

At the end of World War II, a severe 5-mo famine struck the cities in the western part of The Netherlands. At its peak, the rations dropped to as low as 400 calories per day. In 1972, cognitive performance in 19-y-old male conscripts was reported not to have been affected by exposure to the famine before birth. In the present study, we show that cognitive function in later life does seem affected by prenatal undernutrition. We found that at age 56 to 59, men and women exposed to famine during the early stage of gestation performed worse on a selective attention task, a cognitive ability that usually declines with increasing age. We hypothesize that this decline may be an early manifestation of an accelerated cognitive aging process.

Functional consequences of subcortical white matter lesions and MRI-defined brain infarct in an elderly general population

The impact of single and combined effects of subcortical white matter lesions (WMLs) and magnetic resonance imaging (MRI)-defined brain infarct on activities of daily living (ADL), depression, and health status perception was analyzed in community-dwelling elderly individuals. The study included 268 participants from the Memory and Morbidity in Augsburg Elderly (MEMO) project, a population-based study on individuals aged 65 to 83 years, conducted in Augsburg, Germany. Cerebral MRI was performed, and 2 geriatric performance tests, scales to assess ADL, depressive symptoms, and self-perceived health status were assessed. The prevalence of large (>10 mm) subcortical WML was 37.7% and of MRI-defined infarct-like lesions was 15.3%. Both vascular lesion types combined were found in 9% of the participants. Large WMLs were associated with significantly more impairments in basic ADL, inferior results in the performance tests, and a worse self-perceived health status compared to those without large WML. Magnetic resonance imaging-defined brain infarct was associated with impairments in performance tests. Participants with both lesion types were limited in all domains and were 2 to 3 times more likely to have impairments in all examined functions. Their risk of impairment in a specific function was considerably higher than the sum of the single risks associated with each lesion type alone. This study suggests that the single and especially the combined occurrence of common vascular brain lesions are associated with functional impairment. Identifying individuals with severe WML combined with MRI-defined brain infarct can help better understand the development of marked impairments in old age.

Association between cytokines and cerebral MRI changes in the aging brain

The association between cytokines (IL-1 beta, sIL-4R, IL-6, IL-8, IL-10, IL-12, TNF-alpha) and subcortical white matter lesions, cortical atrophy and lacunar infarctions of the aging brain was investigated among 268 elderly community participants. Single pro- and anti-inflammatory cytokines were neither associated with WML nor with atrophy and lacunar infarction. An association between atrophy and the chemokine-cytokine factor (containing sIL-4R, IL-6, IL-8) remained significant after adjustment for age, gender, education, depressive symptoms, diabetes mellitus, cardiovascular diseases (stroke, TIA, myocardial infarction, myocardial insufficiency, arrhythmic heart), hypertension, body-mass index, smoking status and aggregation inhibitors as opposed to single cytokines. Atrophy of the parietal, temporal and occipital lobes was associated with the same cytokine-chemokine factor for both the whole sample or restricted to those without history of stroke/TIA. The results indicate that a combination of chemokine-cytokines rather than single cytokines may contribute to inflammatory processes associated with cortical atrophy in the aging brain.

Single and combined effects of cerebral white matter lesions and lacunar infarctions on cognitive function in an elderly population

BACKGROUND

This study is to investigate the association between single and combined vascular brain changes (white matter lesions [WMLs], lacunar infarctions) and the cognitive domains of memory, processing speed, and motor function in the elderly adults.

METHODS

In a sample of 268 participants aged 65-83 years of the MEMO (Memory and Morbidity in Augsburg Elderly) population-based study in Augsburg, Germany, cerebral magnetic resonance imaging (MRI) was performed and a detailed neuropsychological test battery applied. Analysis of covariance determined the effects of vascular brain changes on domains of cognitive functioning.

RESULTS

Strong associations of large WMLs and of MRI-defined lacunar infarction with three different domains of cognitive function even after adjustment for age, gender, and education were found. The combined occurrence of both lesions affected about one in 10 participants and was associated with a strong decrease in cognitive function in all domains. The difference between the groups with only one lesion type (either large WMLs or MRI-defined infarction) and participants affected by both was significant in the domains of processing speed and memory, even after adjustment for important confounders such as age, gender, education, and comorbidities. The effects of both lesion types on cognitive function were not more than additive.

CONCLUSIONS

Our study shows that both large WMLs and MRI-defined lacunar infarction contribute to impairments in different cognitive domains. The results suggest that their combined occurrence is associated with stronger reductions in cognitive function than each of the two brain lesion types alone.

Subcortical ischemic vascular disease and cognition: A systematic review

Subcortical Ischemic Vascular Disease (SIVD) is underdiagnosed. This review investigates the relationship among SIVD severity, cognitive status and neuroimaging markers.

METHODS

Cohort, cross-sectional and case control studies were searched on ISI, Medline, Scielo, PsychoInfo and LILACS databases published between 1995 and 2006.

RESULTS

The most impaired cognitive domains were executive, attentional and memory retrieval mechanisms. These cognitive features were frequently associated to White Matter Lesions (WML).

CONCLUSIONS

WML is an independent factor in cognitive decline. However, the threshold for this impact is not yet clearly established.

Vascular mild cognitive impairment is highly prevalent after lacunar stroke but does not increase over time: a 2-year follow-up study

Although ample research has been done into cognitive disorders occurring after stroke, relatively few data are available on the development and the course of vascularmild cognitive impairment (VMCI) after first-ever lacunar stroke.

METHODS

A cohort of 95 patients with a first-ever symptomaticlacunar infarct, older than 40 years, MMSE>or=15 and no other neurological or major psychiatric deficits were included. Patients were assessed (clinically and with a neuropsychological test battery) at 1 and 24 months after stroke, and CT was repeated. VMCI was diagnosed when patients had a deficit in at least one cognitive domain, in the absence of dementia.

RESULTS

Approximately 75% of the patients had VMCI at 1 month; this percentage was somewhat lower at 2 years. Only initial stroke severity was an independent predictor of VMCI after stroke.

CONCLUSION

VMCI is highly prevalent after lacunar stroke, but does not increase during the first 2 years thereafter.

Cognitive Performance after Lacunar Stroke Correlates with Leukoaraiosis Severity

BACKGROUND

This study investigates the effect of leukoaraiosis on patients presenting with cognitive impairment after lacunar stroke.

METHODS

Fourty-six patients with cognitive impairment and newly discovered lacunar stroke detected by brain magnetic resonance imaging underwent neuropsychological testing.

RESULTS

Patients with both lacunar infarct and leukoaraiosis performed less well on cognitive measures, compared to those with lacunar infarcts alone. Additionally, leukoaraiosis severity inversely correlated with cognitive performance.

CONCLUSIONS

In patients with lacunar stroke, presence of leukoaraiosis is associated with worse performance in multiple cognitive domains. These findings suggest lacunar infarcts plus leukoaraiosis is a common etiology for vascular dementia.

Neuropsychological abnormalities associated with lacunar infarction

The objective of this study was to assess neuropsychological abnormalities in 40 patients with lacunar infarction. Topography of infarction, presence of isolated or multiple silent infarcts and white matter hyperintensities were correlated with results of neuropsychological tests and subtypes of lacunar infarction. Patients were studied within 1 month after stroke. A total of 21 patients were males and the mean age was 70.7 years; 30% had a single infarction (mean number of infarctions was 3.4). Twelve patients had pure motor hemiparesis, 9 pure sensory stroke, 8 dysarthria-clumsy hand/ataxic hemiparesis, 8 atypical lacunar syndrome, and 3 sensorimotor stroke. The mean score of the Mini-Mental State Examination was 28.4. Mild cognitive impairment of subcortical vascular features occurred in 23 patients and isolated executive disturbances in 4. Neuropsychological results showed that patients with atypical lacunar syndrome followed by pure motor hemiparesis showed significantly more cognitive executive disturbances. Patients with dysarthria-clumsy hand/ataxic hemiparesis accounted for the best scores in some tests of visuoconstructive function and visual memory. In summary, mild neuropsychological disturbances (57.5%) are not infrequent in acute lacunar infarcts especially in patients with atypical lacunar syndrome and pure motor hemiparesis. Neuropsychological impairment should be considered as common clinical feature in acute lacunar infarction.

Metacognition in stroke: bedside assessment and relation to location, size, and stroke severity

BACKGROUND

Frontal syndromes are poorly represented on stroke scales, yet may constitute an important component of the neurologic deficit impacting treatment and rehabilitation efforts.

AIMS

To validate an assessment of a frontal network syndrome score (FNSS) in stroke and to ascertain the relationship of the FNSS to lesion location, volume, and severity in young people with stroke.

METHODS

Accrual through a cognitive stroke registry of young, alert, nonaphasic, nonencephalopathic, nonsubstance abuse prone people who were tested with the 16 domain FNSS within 4 weeks of their stroke. Lesion location was determined by the Cerefy 3-dimensional, digital, coxial brain atlas identifying 6 regions of cerebral interest. Lesion severity was assessed by the National Institute of Health Stroke Score and infarct volume was measured in cubic centimeters.

RESULTS

From a sample of 456 cases in the registry after exclusions of encephalopathy, depression, and aphasia, cases with frontal network syndrome encompassed 132 of 341 persons (39%). Of these patients (n=80) with mean age 45.7 years [confidence interval (CI): 43.4, 48.1], educational level 13.1 years (CI:12.5, 13.6), mean National Institute of Health Stroke Score of 3.3 (CI: 2.6, 4.0), and mean lesion volume 30.3 mL (CI: 13.7, 46.9), had full testing with the FNSS battery yielding sensitivity (93%), specificity (74%), positive predictive value (79%), negative predictive value (90%), and a good interrater reliability (kappa=0.89, P=0.001). Construct validity testing with 15 frontal neuropsychologic tests revealed good to excellent significant Pearson r values in 14 of 15 of the tests. There was no correlation (Pearson's) for lesion volume (r=0.07, P=0.52) but significant correlation with stroke severity (r=0.23, P=0.03). Analysis of variance testing of the FNSS revealed significant differences for all 6 domains without intergroup significant differences for frontal network syndrome domains in the stroke group.

CONCLUSIONS

The FNSS is a valid, practical measure of frontal syndromes in stroke. Frontal syndromes are common in young people with stroke and may be present no matter where the lesion, are not dependent on size of stroke and have a low correlation with stroke severity.

Determinants of prestroke cognitive impairment in stroke associated with small vessel disease

Understanding the determinants of prestroke cognitive impairment (PCI) in stroke associated with small vessel disease (SVD) may shed light on how to prevent further cognitive deterioration after stroke. We administered the Informant Questionnaire on Cognitive Decline (IQCODE) to close informants of 78 consecutive stroke patients who had SVD. PCI, as defined by an average score of IQCODE > or =3.4 was found in 19 (24%) patients. Regression analyses were performed on the following risk factors for PCI: age, years of education, gender, previous stroke, volume of white matter changes, measures of silent lacunes, cerebral atrophy index, medial temporal lobe atrophy and frontal lobe atrophy. Multivariate regression analyses revealed that only cerebral atrophy index (OR 1.5, CI 1.2-1.9, p < 0.001) predicted PCI among patients with SVD.

Lacunar Infarcts: Functional and Cognitive Outcomes at Five Years in Relation to MRI Findings

BACKGROUND

There are few long-term follow-up studies of patients with lacunar infarcts (LIs). The purpose of this 5-year follow-up study was to assess functional and cognitive outcome in relation to MRI findings.

METHODS

81 patients with a first-ever LI were followed for 5 years with respect to mortality, stroke recurrence, functional and cognitive outcome. T(2)-weighted MRI was performed at baseline and at 5 years. The presence of basal ganglia lesions and white matter lesions was scored according to the European Task Force rating scale. Functional outcome was assessed with the Oxford Handicap Scale (OHP). Cognition was assessed with the Mini Mental State Examination (MMSE).

RESULTS

The 5-year mortality was 19%. Predictors for death were age (OR = 1.07, 95% CI 1.03-1.11), ischemic heart disease (OR = 2.1, 95% CI 1.1-4.1) and impairment score (OR = 1.16, 95% CI 1.02-1.32). 30% of the patients had a recurrent stroke. Predictors for recurrent stroke were diabetes mellitus (OR = 1.7, 95% CI 1.2-7.4) and amount of white matter lesions (OR = 1.7, 95% CI 1.2-2.7). 36% of the patients were functionally dependent (defined as OHP >2). Predictors for functional dependency were impairment score (OR = 1.71, 95% CI 1.12-2.59), MMSE (OR = 0.55, 95% CI 0.33-0.91) and stroke recurrence (OR = 84, 95% CI 9.4-745). 16% of the patients had cognitive impairment (defined as MMSE <24). Stroke recurrence and white matter score, but not basal ganglia score, were correlated to cognitive impairment.

CONCLUSIONS

Many LI patients have a good functional outcome at 5 years. For older patients, for patients with an initial severe stroke, and with additional vascular risk factors, however, the prognosis is more severe, with an increased risk for mortality, stroke recurrence, and physical and cognitive decline.

Effect of White Matter Changes on Cognitive Impairment in Patients With Lacunar Infarcts

BACKGROUND AND PURPOSE

Cerebral white matter changes (WMC) and lacunar infarct are both believed to be consequence of small vessel disease. Whether the extent of WMC affect the type and degree of cognitive impairment in patients with lacunar infarct is not clear. The study was undertaken to determine if WMC influences cognition in patients with lacunar infarcts.

METHODS

We recruited consecutive patients who were admitted to the acute stroke unit because of acute lacunar infarcts, mainly documented by diffusion-weighted magnetic resonance imaging. WMC were measured qualitatively and quantitatively. Patients were divided into quartiles according to the distribution of the volume of WMC. Cognition was assessed 12 weeks after stroke by psychometric tests (Chinese version of Mini-Mental State Examination [MMSE], Alzheimer's Disease Assessment Scale-cognition [ADAS-cog], Mattis Dementia Rating Scale-Initiation/ Perseveration subscale [MDRS I/P]) and was compared between patients with varying severity of WMC. Multivariate linear regression analysis was performed to find variables that influenced performance in the psychometric tests.

RESULTS

Among the 94 included patients with acute lacunar infarcts, those patients (n=25) within the highest quartile of WMC were older, had more lacunar infarcts, more severe stroke, and lower prestroke cognitive function compared with those with less WMC. In addition, their performances in psychometric tests were significantly more impaired. Multivariate linear regression analysis revealed that WMC significantly influenced performance in MDRS I/P. WMC did not independently influence performance in MMSE and ADAS-cog.

CONCLUSIONS

Extent of WMC appears to be associated with executive dysfunction in stroke patients with lacunar infarcts. Further large prospective studies with extensive scales of executive function testing are required to confirm this issue.

The Danish PET/depression project: performance on Stroop's test linked to white matter lesions in the brain

The Stroop test (ST) assesses the integrity of prefrontal and cingulate functioning. Patients with major depression perform poorly on the ST, pointing to disturbed function in these areas. We therefore used positron emission tomography to study 41 in-patients with major depression and 46 age- and gender-matched controls during neuropsychological activation with the ST. Magnetic resonance imaging was used for coregistration and for description of the localization of white matter lesions (WML). The cerebral blood flow (CBF) changes during ST were mapped for each of the two study groups, and inter-group differences were calculated on a voxel-by-voxel basis. The patients were followed for 3 to 5 years to ensure diagnostic stability. The control group activated anterior cingulate regions, prefrontal cortices, insula, thalamus and cerebellum. Despite the patients' slower performance with more errors, no significant differences were found comparing the activations in the two groups. The performance was, however, correlated to the number of WML in frontal lobes, insula and adjacent to the basal ganglia, whereas WML in other locations was not related to performance. We thus partly explain the poorer performance by increased frequency of WML in frontostriatal pathways in the depressed patients, impairing neurotransmission.

Long-term prognosis after lacunar infarction

Lacunar infarcts, small deep infarcts that result from occlusion of a penetrating artery, account for about a quarter of all ischaemic strokes. These infarcts have commonly been regarded as benign vascular lesions with a favourable long-term prognosis. However, recent studies have shown that this is only the case early in the disease course. A few years after infarct, there is an increased risk of death, mainly from cardiovascular causes. The risk of recurrent stroke after lacunar infarct is similar to that for most other types of stroke, and patients have an increased risk of developing cognitive decline and dementia. Age, vascular risk factors, high nocturnal blood pressure, and severity of cerebral small-vessel disease at onset have significant prognostic implications for almost all outcomes. More studies on mechanisms, prevention, and treatment are needed to provide specific guidance on the long-term management of patients with lacunar infarcts. Risk-factor modification is likely to play a large part in therapeutic interventions targeted at this stroke subtype.

Age-related white matter changes and cognitive impairment

Age-related white matter changes (WMC) are a frequent finding in CT/MRI of older subjects. The role of WMC in cognitive impairment has been studied in community-dwelling and healthy old people, subjects with vascular risk factors, stroke patients, depressed and demented subjects. Although there are several negative studies, the majority of the evidence points towards an association between WMC and cognitive impairment. Speed of mental processes, attention, concentration, executive functions and visual spatial skills are the cognitive domains more commonly affected. The methodological problems of the negative studies are discussed, a number of unsolved issues are raised stressing the need for longitudinal studies of WMC with a adequate inception cohort.

A descriptive study of function in acute motor stroke

The functional independence measure (FIM) instrument was introduced in 1987 and has proven to be a useful tool for measuring disability in different patient populations. The FIM instrument data collected during inpatient rehabilitation for stroke is very informative, as it is voluminous, comprehensive, and has a uniform reporting mechanism. In contrast to inpatient rehabilitation, there is a paucity of FIM instrument data on acute stroke patients. The purpose of this study was to describe functional level of 100 patients within the first 24 hours of acute care admission. The mean total FIM instrument score was 94.05 (SD +/- 19.31, range = 38-120), the mean motor domain subscore was 61 (SD +/- 17.8, range 23-85), and cognitive was 33.4 (SD +/- 3.3, range 15-35). Significant group differences were identified for age, gender, and disposition for total and/or domain subscores. Significant differences in age, gender, employment, and disposition were found for clinical subscales. This study fills a gap in current knowledge, that of baseline total FIM instrument scores, domain subscores, and six clinical subscales on one particular group of stroke patients, those with a primary motor stroke.

Do white matter changes contribute to the subsequent development of dementia in patients with mild cognitive impairment? A longitudinal study

OBJECTIVE

White matter lesions on brain CT or MRI are a frequent finding in patients with Alzheimer's disease. However, little is known about the prognostic significance of these changes in cognitively impaired individuals who are at risk for subsequent development of dementia. This study aims at investigating the potential impact of white matter lucencies (WML) on brain CT on the course of mild cognitive impairment.

PATIENTS AND METHODS

Twenty-seven patients (mean age 72, SD 4.03) with mild cognitive impairment (MCI) and no signs of cerebrovascular disease were prospectively examined. At their initial presentation, all patients underwent a structured interview for the diagnosis of dementia (SIDAM) and a brain CT. Linear measures of atrophy and visual ratings of white matter changes were performed. At follow-up (mean interval 29 months), these patients were re-examined with the SIDAM. Eight patients had developed dementia and met clinical criteria for Alzheimer's disease (crossover group).

RESULTS

Evaluation of the initial CT scans revealed significantly more frequent and extended white matter abnormalities and a higher degree of temporal lobe atrophy in the crossover group as compared to the cognitively stable group. In the crossover group, high WML severity initially was associated with a lesser degree of temporal lobe atrophy and higher global cognitive performance.

CONCLUSION

We conclude that WML play a role in the dementia process and that they might accelerate cognitive decline in individuals with mild cognitive impairment. WML should be included in prospective studies of MCI as potential predictor variables.

Impact of white matter changes on clinical manifestation of Alzheimer's disease: A quantitative study

BACKGROUND AND PURPOSE

There have been conflicting results involving the clinical significance of white matter changes in patients with Alzheimer's disease (AD). We studied the association between the volume of white matter hyperintensities (WMHs) on T2-weighted images and cognitive, neurological, and neuropsychiatric symptoms.

METHODS

The subjects were 76 AD patients who had WMHs but no obvious cerebrovascular diseases. We quantified the volume of WMHs by using fast-fluid-attenuated inversion recovery images and whole brain atrophy by using 3D spoiled gradient-echo images. Effects of WMHs and brain atrophy on dementia severity, cognitive function, neuropsychiatric disturbances, and neurological findings were examined.

RESULTS

Whole brain atrophy was significantly associated with dementia severity and cognitive disturbances, as well as with grasp reflex and some kinds of neuropsychiatric disturbances. After we controlled for the effects of brain atrophy, duration of symptoms, and demographic factors, we found that WMH volume was not associated with global cognitive disturbances or dementia severity but was significantly associated with urinary incontinence, grasp reflex, and aberrant motor behaviors. Brain atrophy and WMH volume were not significantly correlated either before or after controlling for age, sex, education, and duration of symptoms. WMH volume was associated with hypertension, but brain atrophy was not positively correlated with any vascular risk factors.

CONCLUSIONS

Our results support the hypothesis that WMHs in AD patients are superimposed phenomena of vascular origin. WMHs contribute to specific neurological and neuropsychiatric manifestations but not to global cognitive impairment, which is more closely associated with brain atrophy.

Relation between age-related decline in intelligence and cerebral white-matter hyperintensities in healthy octogenarians: a longitudinal study

BACKGROUND

White-matter hyperintensities are commonly found on magnetic resonance imaging (MRI) of elderly people with or without dementia. Studies of the relation between severity of white-matter hyperintensities and cognitive impairment have had conflicting results. We undertook a longitudinal study of age-related decline in intellectual function and MRI at age 80 years.

METHODS

From a cohort of 698 people born in 1914 and living in seven municipalities in Denmark, 68 healthy non-demented individuals had been tested with the Wechsler adult intelligence scale (WAIS) at ages 50, 60, and 70, and they agreed to further WAIS testing at age 80, and cerebral MRI at age 80-82 (mean age 82.3 years). We scored separately the numbers of periventricular and deep white-matter hyperintensities.

FINDINGS

Scores for periventricular hyperintensities in this sample included all possible degrees of severity, but no participant scored more than 75% of maximum for deep white-matter hyperintensities. Neither type was related to the WAIS IQs of the 80-year assessment, but both were significantly associated with decline in performance IQ from age 50 to age 80 years (bivariate correlation coefficients 0.32, p=0.0087, and 0.28, p=0.0227, respectively). An analysis based on two WAIS subtests showed that the association between white-matter hyperintensities and cognitive impairment was significant only for cognitive decline in the decade 70-80 years.

INTERPRETATION

Both periventricular and deep white-matter hyperintensities are related to decline in intelligence but, in healthy octogenarians, the cumulative effect of these features alone explains only a small part of the large differences among individuals in age-related decline in intelligence. Interpretation of the presence and severity of white-matter hyperintensities in a diagnostic context must be done cautiously.

The influence of ergotamine abuse on psychological and cognitive functioning

Migraine patients abusing ergotamine often have chronic daily headaches associated with tiredness, sleep and memory disturbances, and reduced general well-being. We quantified psychological and cognitive functioning in 12 migraine patients with and 12 without ergotamine abuse (> or = 5 days/week for > or = 6 months) and 12 healthy controls. Psychological functioning assessed by Symptom Checklist-90 (SCL-90) and Profile Of Mood State (POMS), was impaired in ergotamine abusers compared to healthy controls. Cognitive functioning divided into four domains: attention (critical flicker frequency analysis and mental control subscale of the Wechsler Memory Scale (WMS), speed of information processing (reaction time tasks and lexical decision tasks), memory (four subscales of the WMS) and cognitive flexibility (trailmaking test and WMS digits backwards), was impaired in ergotamine abusers in speed of information processing and cognitive flexibility. These differences disappeared after correction for total SCL-90 scores. In conclusion, ergotamine abuse is associated with high psychological distress but not with structural impaired cognitive functioning.

Silent lacunar lesions detected by magnetic resonance imaging of children with brain tumors: a late sequela of therapy

BACKGROUND

Cerebral lacunes, which generally appear on magnetic resonance imaging as foci of white matter loss, usually occur in adults after ischemic infarcts. We report the development of lacunes in children after therapy for brain tumors.

PATIENTS AND METHODS

We reviewed the clinical characteristics and radiologic studies of 524 consecutive children with brain tumors treated over a 10-year period. We documented the neuropsychologic findings associated with lacunes and the factors predictive of lacunar development.

RESULTS

Lacunes developed in none of the 103 patients observed or treated with surgery alone. Twenty-five of the 421 patients treated with chemotherapy or radiation therapy or both had lacunes. Patients were a median of 4.5 years old at the time of both diagnosis (range, 0.3 to 19.8 years) and radiotherapy (range, 1.5 to 20 years). Fourteen patients were treated with craniospinal irradiation, and 11 were treated with local radiotherapy. The median time from radiotherapy to the appearance of lacunes was 2.01 years (range, 0.26 to 5.7 years). For all patients, lacunes were an incidental finding with no corresponding clinical deficits. The factor most predictive of lacunar development was age less than 5 years at the time of radiotherapy (P =.010). There was no significant difference in estimated decline in intelligence quotient scores between patients with lacunes and age and diagnosis-matched controls.

CONCLUSION

Lacunes may be caused by therapy-induced vasculopathy in children with brain tumors, with the most significant predictor being age less than 5 years at the time of radiotherapy.

Magnetic resonance imaging evidence of "silent" cerebrovascular toxicity in cocaine dependence

BACKGROUND

Cocaine and its metabolites can produce vasospasm. Cocaine-dependent (CD) patients are at increased risk for stroke, and a high frequency of brain perfusion defects has been observed in clinically asymptomatic CD subjects. This is the first controlled magnetic resonance imaging (MRI) study of clinically asymptomatic CD subjects.

METHODS

Two age-matched groups of male subjects (61 CD and 57 control) participated in the study. Subjects with a history of neurologic symptoms or major medical or neurologic illness, such as hypertension, diabetes, or significant head trauma, were excluded. The severity of hyperintense lesions observed on T2-weighted MRI images were rated on a 0-3-point scale by an experienced radiologist who was blind to all clinical data. Ratings of 3 were felt to be significant indicators of a possible disease process and were used in the data analysis. Three regions were separately rated: the cerebral white matter, subinsular white matter, and subcortical gray matter (basal ganglia and thalamus region).

RESULTS

Despite the exclusion criteria minimizing risk factors for cerebrovascular events, 17 of the 61 (27.9%) CD subjects and 4 of 57 (7%) of the control subjects had severe hyperintense lesions suggestive of subclinical or "silent" anoxic vascular events. Significant group differences were observed in the two white matter regions but not in the subcortical gray matter region. The risk of severe white matter lesions in the CD group increased with age, reaching 50% in the oldest age quartile (46-58 years), and this increase was not related to the number of years cocaine was used.

CONCLUSIONS

The data suggest that asymptomatic CD patients are a heterogeneous population with a significantly increased age-related risk of white matter neurovascular toxicity. Premature neurovascular damage may impact treatment outcomes and, as the CD population ages, may manifest as an increased incidence of cognitive deficits.

Variable agreement between visual rating scales for white matter hyperintensities on MRI. Comparison of 13 rating scales in a poststroke cohort

BACKGROUND AND PURPOSE

Previous reports on the frequency, extent, and clinical correlates of white matter hyperintensities (WMHIs) have been contradictory. The purpose of this study was to test whether part of this variation could be explained by the different properties of the visual WMHI rating scales used.

METHODS

The periventricular (PVHIs) and deep white matter (DWMHIs) hyperintensities of 395 poststroke patients were systematically analyzed and transformed to correspond to 13 different rating scales. The scales were compared with the use of Goodman-Kruskal measures of association. The relative frequencies, means, and medians of PVHI and DWMHI grades as well as Spearman rank correlations between WMHI grade and hypertension were calculated.

RESULTS

At best more than 80% of the patients received an equivalent WMHI grade by different scales, but at worst the corresponding values were only 0.4% for PVHI and 18% for DWMHI. At best different scales categorized patients similarly in regard to WMHI grade, but at worst the corresponding values were 8% for PVHI and 57% for DWMHI ratings. The distribution of WMHI grades also varied, and when the effect of age on WMHI was assessed, some of the scales had a ceiling effect and some had a floor effect. Only 1 of the 7 PVHI, 5 of the 9 DWMHI, and 1 of the 3 combined rating scales showed a significant correlation with arterial hypertension, a putative risk factor for WMHIs.

CONCLUSIONS

Some of the inconsistencies in previous studies of WMHIs are due to differences in visual rating scales. Our findings may warrant international debate regarding harmonization of WMHI ratings.