Associations between elevated homocysteine, cognitive impairment, and reduced white matter volume in healthy old adults

Hyperhomocysteinemia and its effect on ageing and language functions - HEAL study

Hyperhomocysteinemia or high levels (> 15 µmol/L) of homocysteine (Hcy)in the blood has been suggested to affect the brain through vascular and neurodegenerative pathways and potentially impact cognition. The current study aims to explore the association of high homocysteine with cognition and brain volume changes in a cohort of middle and old agedr adults. The study recruited 1296 participants aged ≥ 45 years from Tata Longitudinal Study of Ageing (TLSA), an ongoing cohort study. The participants underwent detailed cognitive assessments using Addenbrooke's Cognitive Examination-III (ACE-III) and Computerized Assessment of Adult Information Processing (COGNITO) neuropsychological battery and MR imaging using a 3T scanner. The participants were classified based on the median homocysteine level (16.89 µmol/L) into low Hcy (≤ median) and high Hcy (> median) groups. When adjusted for age, gender, years of education, vitamin B12, folate and dyslipidaemia, Generalised Linear Model (GLM) found a significant association of high Hcy with vocabulary task [β (95% CI) - 1.354 (- 2.655, - 0.052); p = 0.041]. Significant associations was also obtained between cerebral white matter volume and high Hcy [β (95% CI) - 5617.182 (- 11062.762, - 173.602); p = 0.043]. The results suggest that people with high Hcy levels performed poorer in cognitive tasks related to language domain and had lesser cerebral white matter volume. This indicates that homocysteine might have a profound impact on brain structure as well as function.

Cortical lobar volume reductions associated with homocysteine-related subcortical brain atrophy and poorer cognition in healthy aging

Homocysteine (Hcy) is a cardiovascular risk factor implicated in cognitive impairment and cerebrovascular disease but has also been associated with Alzheimer's disease. In 160 healthy older adults (mean age = 69.66 ± 9.95 years), we sought to investigate the association of cortical brain volume with white matter hyperintensity (WMH) burden and a previously identified Hcy-related multivariate network pattern showing reductions in subcortical gray matter (SGM) volumes of hippocampus and nucleus accumbens with relative preservation of basal ganglia. We additionally evaluated the potential role of these brain imaging markers as a series of mediators in a vascular brain pathway leading to age-related cognitive dysfunction in healthy aging. We found reductions in parietal lobar gray matter associated with the Hcy-SGM pattern, which was further associated with WMH burden. Mediation analyses revealed that slowed processing speed related to aging, but not executive functioning or memory, was mediated sequentially through increased WMH lesion volume, greater Hcy-SGM pattern expression, and then smaller parietal lobe volume. Together, these findings suggest that volume reductions in parietal gray matter associated with a pattern of Hcy-related SGM volume differences may be indicative of slowed processing speed in cognitive aging, potentially linking cardiovascular risk to an important aspect of cognitive dysfunction in healthy aging.

Analysis of Risk Factors for White Matter Hyperintensity in Older Adults without Stroke

BACKGROUND

White matter hyperintensity (WMH) is prevalent in older adults aged 60 and above. A large proportion of people with WMH have not experienced stroke and little has been reported in the literature.

METHODS

The case data of patients aged ≥60 years without stroke in Wuhan Tongji Hospital from January 2015 to December 2019 were retrospectively analyzed. It was a cross-sectional study. Univariate analysis and logistic regression were used to analyze independent risk factors for WMH. The severity of WMH was assessed using the Fazekas scores. The participants with WMH were divided into periventricular white matter hyperintensity (PWMH) group and deep white matter hyperintensity (DWMH) group, then the risk factors of WMH severity were explored separately.

RESULTS

Eventually, 655 patients were included; among the patients, 574 (87.6%) were diagnosed with WMH. Binary logistic regression showed that age and hypertension were associated with the prevalence of WMH. Ordinal logistic regression showed that age, homocysteine, and proteinuria were associated with the severity of WMH. Age and proteinuria were associated with the severity of PWMH. Age and proteinuria were associated with the severity of DWMH.

CONCLUSIONS

The present study showed that in patients aged ≥60 years without stroke, age and hypertension were independent risk factors for the prevalence of WMH; while the increasing of age, homocysteine, and proteinuria were associated with greater WMH burden.

Relationship between homocysteine and cognitive impairment in elderly patients with chronic kidney disease

<b>Aim:</b> To investigate the association of serum homocysteine levels with cognitive function in elderly patients with chronic kidney disease (CKD).<br /> <b>Methods:</b> A case-control study on 200 elderlies &gt;60 years who were distributed into two groups: group 1 (cases): 100 patients with CKD and group 2 (controls): 100 subjects who do not have CKD. All subjects undergo comprehensive geriatric assessment, cognitive assessment, and biochemical investigations including serum homocysteine.<br /> <b>Results:</b> The odds ratio of having impaired clinical dementia rating scores is 3.1 for CKD cases compared to controls. CKD patients have almost 3 times the risk of having cognitive impairment [OR=3.1; 95% CI (1.6-6.0)]. The mean serum homocysteine (18.2 μmol/L) among CKD showed a highly statistically significance compared to controls (10.1 μmol/L). Performance of multiple cognitive domains was reduced in association with elevated homocysteine levels. By using linear regression model for the factors independently related to cognitive performance among studied CKD cases, it was found that diabetes mellitus, educational level, age, and serum homocysteine level were strongly associated with consortium to establish a registry for Alzheimer’s disease neuropsychological battery total scores. Respecting the percentage variance explained by each significant variable (R²), serum homocysteine level is an independent significant variable predictor with the total scores.<br /> <b>Conclusion:</b> The main features of cognitive impairment in CKD patients are executive dysfunction and memory impairment. Poor cognitive function in CKD patients was related with a higher homocysteine level independently.

Association of homocysteine-related subcortical brain atrophy with white matter lesion volume and cognition in healthy aging

Homocysteine (Hcy) is a vascular risk factor associated with cognitive impairment and cerebrovascular disease but has also been implicated in Alzheimer's disease (AD). Using multivariate Scaled Subprofile Model (SSM) analysis, we sought to identify a network pattern in structural neuroimaging reflecting the regionally distributed association of plasma Hcy with subcortical gray matter (SGM) volumes and its relation to other health risk factors and cognition in 160 healthy older adults, ages 50-89. We identified an SSM Hcy-SGM pattern that was characterized by bilateral hippocampal and nucleus accumbens volume reductions with relative volume increases in bilateral caudate, pallidum, and putamen. Greater Hcy-SGM pattern expression was associated with greater white matter hyperintensity (WMH) volume, older age, and male sex, but not with other vascular and AD-related risk factors. Mediation analyses revealed that age predicted WMH volume, which predicted Hcy-SGM pattern expression, which, in turn, predicted cognitive processing speed performance. These findings suggest that the multivariate SSM Hcy-SGM pattern may be indicative of cognitive aging, reflecting a potential link between vascular health and cognitive dysfunction in healthy older adults.

Homocysteine Modulates Brain Functional Connectivity in a Memory Retrieval Task

Background: Homocysteine, a methionine metabolite, is a recognized risk factor for accelerated age-related cognitive decline and dementia. Objective: In the light of studies indicating increases in brain activity and brain functional connectivity in the early stages of age-related cognitive decline, we undertook a study to examine the relationship between plasma homocysteine levels and brain functional connectivity in a group of late middle-aged males at risk of cognitive decline due to high body mass index and a sedentary lifestyle. Methods: Brain functional connectivity was measured using the steady state visual evoked potential event related partial coherence while 38 participants performed a memory task where each trial comprised an object recognition task followed by a location memory task. Results: We observed a significant transient peak in the correlation between plasma homocysteine levels and fronto-parietal brain functional connectivity immediately before the presentation of the memory location component of the task. Significantly, this correlation was only apparent if the participant pool included individuals with homocysteine concentrations above 11μmole/L. Conclusion: Our findings suggest that the increased brain functional connectivity observed in the earlier stages of age-related cognitive decline reflects pathognomonic changes in brain function and not compensatory changes engaged to enhance task performance. Our findings also suggest that homocysteine interferes with the inhibition of cortical networks where this inhibition is necessary for optimum task performance. Finally, we observed that the effect of homocysteine on brain functional connectivity is only apparent at concentrations above 11μmol/L.

One-Carbon Metabolism Biomarkers and Risks of Incident Neurocognitive Disorder among Cognitively Normal Older Adults

There is a lack of evidence supporting an association between folate and vitamin B12 exposure with cognitive outcomes. We examined serum folate and vitamin B12 and plasma homocysteine in 690 cognitively-normal adults (aged ≥ 55) from the Singapore Longitudinal Aging Study (SLAS-2) followed-up over 4.5 years on incident neurocognitive disorder (NCD): mild cognitive impairment (MCI) and dementia. At follow-up, 5.7% (39) of participants developed NCD (34 MCI and 5 dementia). Comparing with those who remained cognitively-normal, participants progressed to NCD had significantly lower mean baseline vitamin B12 (420 [SD ± 221] vs. 510 [SD ± 290] pmol/L, p = 0.026), higher homocysteine (14.6 [SD ± 4.2] vs. 12.9 [SD ± 4.3], p = 0.018) and lower one-carbon index (Z-scores: −0.444 [SD ± 0.819] vs. −0.001 [SD ± 0.990], p = 0.006). Adjusted for confounders, significant associations with incident NCD were found for lower vitamin B12 (per-SD OR = 2.10, 95%CI = 1.26–3.52), higher homocysteine (per-SD OR = 1.96, 95%CI = 1.18–3.24) and lower one-carbon index (per-SD OR = 1.67, 95%CI = 1.06–2.64). Folate was not significantly associated with progression to NCD. Notably, low B12 in the presence of high folate was significantly associated with incident NCD (adjusted OR = 3.81, 95%CI = 1.04–13.9). Low B12, high homocysteine, low B12 in the presence of high folate, and a one-carbon index of hypo-methylation were independently associated with progression to NCD among cognitively normal.

Elevated homocysteine levels, white matter abnormalities and cognitive impairment in patients with late-life depression

Background

Cognitive impairment in late−life depression (LLD) is considered to be caused by neurodegenerative changes. Elevated homocysteine (Hcy) levels may be linked to cognitive abnormalities associated with LLD. The important role of white matter (WM) damage in cognitive impairment and pathogenesis in patients with LLD has been widely reported. However, no research has explored the interrelationships of these features in patients with LLD.

Objective

The goal of the study was to examine the interrelationship between Hcy levels, cognition, and variations in WM microstructure detected by diffusion tensor imaging (DTI) in patients with LLD.

Methods

We recruited 89 healthy controls (HCs) and 113 patients with LLD; then, we measured the plasma Hcy levels of participants in both groups. All individuals performed a battery of neuropsychological tests to measure cognitive ability. Seventy-four patients with LLD and 68 HCs experienced a DTI magnetic resonance imaging (MRI) scan.

Results

Patients with LLD showed significantly lower fractional anisotropy (FA) values in the bilateral inferior longitudinal fasciculus than those of healthy participants. Only in LLD patients was Hcy concentration inversely associated to FA values in the forceps minor. Finally, multiple regression analyses showed that an interaction between Hcy levels and FA values in the right cingulum of the cingulate cortex and right inferior longitudinal fasciculus were independent contributors to the executive function of patients with LLD.

Conclusion

Our results highlight the complex interplay between elevated homocysteine levels and WM abnormalities in the pathophysiology of LLD-related cognitive impairment, consistent with the neurodegeneration hypothesis.

Brain ventricles, CSF and cognition: a narrative review

The brain ventricles are structures that have been related to cognition since antiquity. They are essential components in the development and maintenance of brain functions. The aging process runs with the enlargement of ventricles and is related to a less selective blood-cerebrospinal fluid barrier and then a more toxic cerebrospinal fluid environment. The study of brain ventricles as a biological marker of aging is promissing because they are structures easily identified in neuroimaging studies, present good inter-rater reliability, and measures of them can identify brain atrophy earlier than cortical structures. The ventricular system also plays roles in the development of dementia, since dysfunction in the clearance of beta-amyloid protein is a key mechanism in sporadic Alzheimer's disease. The morphometric and volumetric studies of the brain ventricles can help to distinguish between healthy elderly and persons with mild cognitive impairment (MCI) and dementia. Brain ventricle data may contribute to the appropriate allocation of individuals in groups at higher risk for MCI-dementia progression in clinical trials and to measuring therapeutic responses in these studies, as well as providing differential diagnosis, such as normal pressure hydrocephalus. Here, we reviewed the pathophysiology of healthy aging and cognitive decline, focusing on the role of the choroid plexus and brain ventricles in this process.

The association between vitamin B12 and plasma homocysteine levels with episodic memory and the volume of memory related brain structures in middle-aged individuals: a retrospective correlational study

In previous studies, decreased vitamin B12 and increased plasma homocysteine levels were reported as risk factors for dementia. The aim of this study was to clarify this relationship in earlier ages. Twenty-one healthy middle-aged adults (9 females, 12 males) with a mean age of 46.21 ± 7.99 were retrospectively included in the study. A voxel-based morphometry analysis was performed to measure brain volume. Plasma homocysteine, vitamin B12 levels, verbal and non-verbal memory test performances were recorded. Correlation analyses showed that increased plasma homocysteine was associated with lower memory score. Decreased vitamin B12 level was found to be associated with smaller brain volume in temporal regions. These results suggest that vitamin B12 and plasma homocysteine levels are associated with brain and cognition as early as middle adulthood. Future studies are needed to clarify whether they might be utilized as early hematological biomarkers to predict cognitive decline and neural loss.

Hypertension With High Homocysteine Is Associated With Default Network Gray Matter Loss

Hypertension with high homocysteine (Hcy, ≥10 μmol/L) is also known as H-type hypertension (HHT) and proposed as an independent risk factor for stroke and cognitive impairment. Although previous studies have established the relationships among hypertension, Hcy levels, and cognitive impairment, how they affect brain neuroanatomy remains unclear. Thus, we aimed to investigate whether and to what extent hypertension and high Hcy may affect gray matter volume in 52 middle-aged HHT patients and 51 demographically matched normotensive subjects. Voxel-based morphological analysis suggested that HHT patients experienced significant gray matter loss in the default network. The default network atrophy was significantly correlated with Hcy level and global cognitive function. These findings provide, to our knowledge, novel insights into how HHT affects brain gray matter morphology through blood pressure and Hcy.

Ophthalmic changes in a spaceflight analog are associated with brain functional reorganization

Following long-duration spaceflight, some astronauts exhibit ophthalmic structural changes referred to as Spaceflight Associated Neuro-ocular Syndrome (SANS). Optic disc edema is a common sign of SANS. The origin and effects of SANS are not understood as signs of SANS have not manifested in previous spaceflight analog studies. In the current spaceflight analog study, 11 subjects underwent 30 days of strict head down-tilt bed rest in elevated ambient carbon dioxide (HDBR+CO2 ). Using functional magnetic resonance imaging (fMRI), we acquired resting-state fMRI data at 6 time points: before (2), during (2), and after (2) the HDBR+CO2 intervention. Five participants developed optic disc edema during the intervention (SANS subgroup) and 6 did not (NoSANS group). This occurrence allowed us to explore whether development of signs of SANS during the spaceflight analog impacted resting-state functional connectivity during HDBR+CO2 . In light of previous work identifying genetic and biochemical predictors of SANS, we further assessed whether the SANS and NoSANS subgroups exhibited differential patterns of resting-state functional connectivity prior to the HDBR+CO2 intervention. We found that the SANS and NoSANS subgroups exhibited distinct patterns of resting-state functional connectivity changes during HDBR+CO2 within visual and vestibular-related brain networks. The SANS and NoSANS subgroups also exhibited different resting-state functional connectivity prior to HDBR+CO2 within a visual cortical network and within a large-scale network of brain areas involved in multisensory integration. We further present associations between functional connectivity within the identified networks and previously identified genetic and biochemical predictors of SANS. Subgroup differences in resting-state functional connectivity changes may reflect differential patterns of visual and vestibular reweighting as optic disc edema develops during the spaceflight analog. This finding suggests that SANS impacts not only neuro-ocular structures, but also functional brain organization. Future prospective investigations incorporating sensory assessments are required to determine the functional significance of the observed connectivity differences.

A novel hippocampus metabolite signature in diabetes mellitus rat model of diabetic encephalopathy

Diabetic encephalopathy (DE) is one of the chronic complications of diabetes. Even then, the molecular mechanism underlying DE remains unexplored. In this study, we have made an attempt to investigate the metabolic changes associated with the streptozocin (STZ)-induced cognitive dysfunction in the hippocampus of the rat model, a classical rodent model for DE, with the help of Gas Chromatography-Mass Spectrometry-based method. The STZ injections led to the rise of mean blood glucose levels in the diabetes mellitus (DM) group of rats as compared to the control (CON) group of rats throughout the experiment. However, we did not find any significant difference between the blood glucose levels of the DM & the CON groups of rats before the STZ injection. The results indicated a behavioral and morphological cognitive dysfunction in the DM groups of rats. The metabolomic investigation of these DE rats demonstrated a lower level of N-acetylaspartate and dihydroxyacetone phosphate accompanied by a higher level of homocysteine and glutamate as against the CON group of rats. The outcome of this study may unravel the underlying pathophysiological mechanism of DE. Also, the metabolomic data from this study may provide a platform for the development of DE biomarkers.

The Association between Mushroom Consumption and Mild Cognitive Impairment: A Community-Based Cross-Sectional Study in Singapore

We examined the cross-sectional association between mushroom intake and mild cognitive impairment (MCI) using data from 663 participants aged 60 and above from the Diet and Healthy Aging (DaHA) study in Singapore. Compared with participants who consumed mushrooms less than once per week, participants who consumed mushrooms >2 portions per week had reduced odds of having MCI (odds ratio = 0.43, 95% CI 0.23-0.78, p = 0.006) and this association was independent of age, gender, education, cigarette smoking, alcohol consumption, hypertension, diabetes, heart disease, stroke, physical activities, and social activities. Our cross-sectional data support the potential role of mushrooms and their bioactive compounds in delaying neurodegeneration.

The relationship between cognitive impairment and homocysteine in a B12 and folate deficient population in China: A cross-sectional study

Alzheimer disease (AD) is the most common neurodegenerative disease in the world. The relationship between AD and homocysteine (Hcy) is contradictory.A community-based investigation was conducted to find patients with AD in a vitamin B deficient population (≥55 years old) in Lüliang area in China. Venous blood samples were collected. Serum Hcy, folate, and vitamin B12 were measured. For each case, 4 controls were selected matched with age to evaluate the relationship between Hcy and AD.The crude prevalence of AD among people ages 55 years or older in this area was 8.60%. There were significant differences in serum Hcy and B12 between the case and control groups. We found that the higher level of serum Hcy was associated with a high risk of AD, and higher education level, higher folate and B12 concentration were protective factors to AD.Adjustment of diet structure and supplementation of folate and B12 may offer potential therapeutic measures in this area.

Meta-analysis of cognitive functioning in patients following kidney transplantation

Background

There is mixed evidence regarding the nature of cognitive function in patients who have undergone renal transplantation. The aim of this meta-analysis was to examine which cognitive domains are impacted following kidney transplantation and how performance compares with non-transplanted patients or healthy controls/normative data.

Method

A systematic search was conducted using keywords within three databases (Embase, MEDLINE and PsychINFO), yielding 458 unique studies, 10 of which met the inclusion criteria. Neuropsychological tests were grouped into nine cognitive domains and three separate analyses were undertaken within each domain: (i) within subjects pre- versus post-transplant, (ii) transplanted versus non-transplanted patients and (iii) transplanted versus healthy matched controls and standardized normative data.

Results

Transplanted patients showed moderate to large improvements in the domains of general cognitive status (g = 0.526), information and motor speed (g = 0.558), spatial reasoning (g = 0.376), verbal memory (g = 0.759) and visual memory (g = 0.690) when compared with their pre-operative scores. Test scores in the same five domains were significantly better in post-transplanted patients when compared with dialysis-dependant or conservatively managed chronic kidney disease patients. However, post-transplanted patients’ performance was significantly low compared with that of healthy controls (and standardized normative data) in the domains of executive functioning (g = −0.283), verbal fluency (g = −0.657) and language (g = −0.573).

Conclusions

Two key issues arise from this review. First, domain-specific cognitive improvement occurs in patients after successful transplantation. Nevertheless, transplanted patients still performed significantly below healthy controls in some domains. Second, there are important shortcomings in existing studies; the length of follow-up is typically short and only limited neuropsychological test batteries are employed. These factors are important in order to support the recovery of cognitive function among patients following renal transplant.

Inflammation and cerebral small vessel disease: A systematic review

Inflammation is increasingly implicated as a risk factor for dementia, stroke, and small vessel disease (SVD). However, the underlying mechanisms and causative pathways remain unclear. We systematically reviewed the existing literature on the associations between markers of inflammation and SVD (i.e., white matter hyperintensities (WMH), lacunes, enlarged perivascular spaces (EPVS), cerebral microbleeds (CMB)) in cohorts of older people with good health, cerebrovascular disease, or cognitive impairment. Based on distinctions made in the literature, markers of inflammation were classified as systemic inflammation (e.g. C-reactive protein, interleukin-6, fibrinogen) or vascular inflammation/endothelial dysfunction (e.g. homocysteine, von Willebrand factor, Lp-PLA2). Evidence from 82 articles revealed relatively robust associations between SVD and markers of vascular inflammation, especially amongst stroke patients, suggesting that alterations to the endothelium and blood-brain barrier may be a driving force behind SVD. Conversely, cross-sectional findings on systemic inflammation were mixed, although longitudinal investigations demonstrated that elevated levels of systemic inflammatory markers at baseline predicted subsequent SVD severity and progression. Importantly, regional analysis revealed that systemic and vascular inflammation were differentially related to two distinct forms of SVD. Specifically, markers of vascular inflammation tended to be associated with SVD in areas typical of hypertensive arteriopathy (e.g., basal ganglia), while systemic inflammation appeared to be involved in CAA-related vascular damage (e.g., centrum semiovale). Nonetheless, there is insufficient data to establish whether inflammation is causal of, or secondary to, SVD. Findings have important implications on interventions, suggesting the potential utility of treatments targeting the brain endothelium and blood brain barrier to combat SVD and associated neurodegenerative diseases.

Neurological disorders in vitamin B12 deficiency

The review discusses thesteps of vitamin B12 metabolism and its role in maintaining of neurological functions. The term "vitamin B12 (cobalamin)" refers to several substances (cobalamins) of a very similar structure. Cobalamin enters the body with animal products. On the peripherу cobalamin circulates only in binding with proteins transcobalamin I and II (complex cobalamin-transcobalamin II is designated as "holotranscobalamin"). Holotranscobalamin is absorbed by different cells, whereas transcobalamin I-binded vitamin B12 - only by liver and kidneys. Two forms of cobalamin were identified as coenzymes of cellular reactions which are methylcobalamin (in cytoplasm) and hydroxyadenosylcobalamin (in mitochondria). The main causes of cobalamin deficiency are related to inadequate intake of animal products, autoimmune gastritis, pancreatic insufficiency, terminal ileum disease, syndrome of intestinal bacterial overgrowth. Relative deficiency may be seen in excessive binding of vitamin B12 to transcobalamin I. Cobalamin deficiency most significantly affects functions of blood, nervous system and inflammatory response. Anemia occurs in 13-15% of cases; macrocytosis is an early sign. The average size of neutrophils and monocytes is the most sensitive marker of megaloblastic hematopoiesis. The demands in vitamin B12 are particularly high in nervous tissue. Hypovitaminosis is accompanied by pathological lesions both in white and gray brain matter. Several types of neurological manifestations are described: subacute combined degeneration of spinal cord (funicular myelinosis), sensomotor polyneuropathy, optic nerve neuropathy, cognitive disorders. The whole range of neuropsychiatric disorders with vitamin B12 deficiency has not been studied well enough. Due to certain diagnostic difficulties they are often regarded as "cryptogenic", "reactive", "vascular» origin. Normal or decreased total plasma cobalamin level could not a reliable marker of vitamin deficiency. In difficult cases the content of holotranscobalamin, methylmalonic acid / homocysteine, and folate in the blood serum should be investigated besides carefully analysis of clinical manifestations.

Association of homocysteine, folate, and white matter hyperintensities in Parkinson's patients with different motor phenotypes

OBJECTIVE

To investigate the association of homocysteine (Hcy), folate, and white matter hyperintensities in Parkinson's disease (PD) with different motor phenotypes.

METHODS

Of the PD patients, 176 were included. Based on the Unified Parkinson's Disease Rating Scale, the PD patients were classified into postural instability gait disorder (PIGD) and non-PIGD phenotypes. According to the Fazekas score, patients were divided into the none/mild white matter hyperintensity (WMH) group and the moderate/severe WMH group. The relationship of Hcy, folate, and white matter hyperintensities (WMHs), and the motor phenotype of PD were analyzed.

RESULTS

PD-PIGD patients had higher proportion of moderate/severe WMHs, Hcy levels, and lower folate levels than PD-non-PIGD patients (p all ≤ 0.001). In the subgroup analysis, patients with both PD-PIGD and moderate/severe WMHs had the highest Hcy and lowest folate levels compared with others. Binary logistic regression analysis showed that age, folate, and Hcy were independent risk factors for WMHs. In an a priori-determined stratified analysis, after adjustment for confounding factors, the odds ratio of WMHs was 8.01 (95% CI 2.700-23.767, p trend = 0.001) in the patients with Hcy levels in the highest quintile compared with the lowest quintile and 16.81 (95% CI 4.74-59.65, p trend < 0.001) in the patients with folate levels in the lowest quintile compared with the highest quintile.

CONCLUSIONS

Our data showed a close association between WMHs and Hcy, folate especially in PD-PIGD patients. It can be speculated that higher Hcy and lower folate probably played important roles in the development of WMHs and motor heterogeneity in PD.

Homocysteine and Cerebral Atrophy: The Epidemiology of Dementia in Singapore Study

BACKGROUND

Plasma homocysteine levels are increasingly studied as a potential risk factor for dementia. Elevated homocysteine levels have been linked with gray and white matter volume reduction among individuals with mild cognitive impairment and Alzheimer's disease. However, the effects of homocysteine on brain changes in preclinical stages of dementia remain unexplored.

OBJECTIVE

To examine the association of elevated homocysteine levels with markers of neurodegeneration, i.e., white and gray matter volume in an elderly population.

METHODS

The study included 768 participants (mean age: 69.6±6.5 years, 51.3% women) from the Epidemiology of Dementia In Singapore study. Participants underwent a brain MRI scan and blood tests. Serum homocysteine was measured using competitive immunoassay. Cortical thickness and subcortical structural volume were quantified using FreeSurfer whereas white matter volume was quantified using a previous validated method.

RESULTS

Higher homocysteine levels were significantly associated with decreased global white matter volume [mean difference (β) in volume (ml) per micromole per liter (μmol/l) increase in homocysteine levels: - 0.555, 95% Confidence Interval (CI): - 0.873; - 0.237], decreased parietal cortical thickness [β in thickness (μm) per μmol/l increase in homocysteine levels:- 1.429, 95% CI: - 2.781; - 0.077], and smaller volumes of the thalamus [β: - 0.017, 95% CI: - 0.026; - 0.008], brainstem [β: - 0.037, 95% CI: - 0.058; - 0.016], and accumbens [β: - 0.004, 95% CI: - 0.006; - 0.002].

CONCLUSION

Higher homocysteine levels were associated with cerebral atrophy. Further studies are required to assess whether lowering plasma homocysteine levels may prevent neurodegenerative changes or delay progression of clinical symptoms before the development of dementia.

Examining the relationship between nutrition and cerebral structural integrity in older adults without dementia

The proportion of adults aged 60 years and over is expected to increase over the coming decades. This ageing of the population represents an important health issue, given that marked reductions to cerebral macro- and microstructural integrity are apparent with increasing age. Reduced cerebral structural integrity in older adults appears to predict poorer cognitive performance, even in the absence of clinical disorders such as dementia. As such, it is becoming increasingly important to identify those factors predicting cerebral structural integrity, especially factors that are modifiable. One such factor is nutritional intake. While the literature is limited, data from available cross-sectional studies indicate that increased intake of nutrients such as B vitamins (for example, B6, B12 and folate), choline, n-3 fatty acids and vitamin D, or increased adherence to prudent whole diets (for example, the Mediterranean diet) predicts greater cerebral structural integrity in older adults. There is even greater scarcity of randomised clinical trials investigating the effects of nutritional supplementation on cerebral structure, though it appears that supplementation with B vitamins (B6, B12 and folic acid) or n-3 fatty acids (DHA or EPA) may be beneficial. The current review presents an overview of available research examining the relationship between key nutrients or adherence to select diets and cerebral structural integrity in dementia-free older adults.

Glycerophospholipid Supplementation as a Potential Intervention for Supporting Cerebral Structure in Older Adults

Modifying nutritional intake through supplementation may be efficacious for altering the trajectory of cerebral structural decline evident with increasing age. To date, there have been a number of clinical trials in older adults whereby chronic supplementation with B vitamins, omega-3 fatty acids, or resveratrol, has been observed to either slow the rate of decline or repair cerebral tissue. There is also some evidence from animal studies indicating that supplementation with glycerophospholipids (GPL) may benefit cerebral structure, though these effects have not yet been investigated in adult humans. Despite this paucity of research, there are a number of factors predicting poorer cerebral structure in older humans, which GPL supplementation appears to beneficially modify or protect against. These include elevated concentrations of homocysteine, unbalanced activity of reactive oxygen species both increasing the risk of oxidative stress, increased concentrations of pro-inflammatory messengers, as well as poorer cardio- and cerebrovascular function. As such, it is hypothesized that GPL supplementation will support cerebral structure in older adults. These cerebral effects may influence cognitive function. The current review aims to provide a theoretical basis for future clinical trials investigating the effects of GPL supplementation on cerebral structural integrity in older adults.

Homocysteine and Real-Space Navigation Performance among Non-Demented Older Adults

BACKGROUND

High plasma homocysteine (Hcy) level is related to higher risk of Alzheimer's disease (AD) and lower cognitive performance in older adults.

OBJECTIVE

To assess the association between plasma Hcy level and real-space navigation performance and the role of vascular risk and protective factors, APOE status, and white matter lesions (WML) on this association.

METHODS

Ninety-two non-demented older adults (29 with amnestic mild cognitive impairment, 46 with subjective cognitive decline, and 17 cognitively normal older adults) underwent spatial navigation testing of egocentric, allocentric, and mixed navigation in a real-space analogue of the Morris water maze, neuropsychological examination, blood collection, and MRI brain scan with evaluation of WML.

RESULTS

In the regression analyses controlling for age, gender, education, and depressive symptoms, higher plasma Hcy level was related to worse mixed and egocentric (β= 0.31; p = 0.003 and β= 0.23; p = 0.017) but not allocentric (p > 0.05) navigation performance. Additional controlling for vascular risk and protective factors, WML, and APOE status did not modify the results. High total cholesterol and low vitamin B12 and folate levels increased the adverse effect of Hcy on egocentric and mixed navigation. WML did not explain the association between plasma Hcy level and navigation performance.

CONCLUSION

Elevated plasma Hcy level may affect real-space navigation performance above and beyond vascular brain changes. This association may be magnified in the presence of high total cholesterol and low folate or vitamin B12 levels. Attention to the level of plasma Hcy may be a viable intervention strategy to prevent decline in spatial navigation in non-demented older adults.

CerefolinNAC Therapy of Hyperhomocysteinemia Delays Cortical and White Matter Atrophy in Alzheimer's Disease and Cerebrovascular Disease

We examined whether using a medical food therapy for hyperhomocysteinemia (HHcy) in patients with Alzheimer's disease (AD) or cognitive impairment due to cerebrovascular disease (CVD) with Cerefolin®/CerefolinNAC® (CFLN: L-methylfolate, methylcobalamin, and N-acetyl-cysteine) slowed regional brain atrophy. Thirty HHcy patients with AD and related disorders (ADRD) received CFLN (HHcy+CFLN: duration [μ ±  σ] = 18.6±16.1 months); a sub-sample of this group did not receive CFLN for varying periods of time (HHcy+NoCFLN: duration [μ ±  σ] = 12.6±5.6 months). Thirty-seven NoHHcy patients with ADRD did not receive CFLN (NoHHcy+NoCFLN: duration [μ ±  σ] = 13.3±17.7 months). No participant took supplemental B vitamins. Regional brain volumes were measured at baseline and end of study, and covariate-adjusted rates of hippocampal, cortical, and forebrain parenchymal (includes white matter) atrophy were predicted. The HHcy+CFLN group's hippocampal and cortical atrophy adjusted rates were 4.25 and 11.2 times slower than those of the NoHHcy+NoCFLN group (p < 0.024). The HHcy+CFLN group's forebrain parenchyma atrophy rate was significantly slower only for CVD; the rate of slowing was proportional to the degree of homocysteine lowering (p < 0.0001). CFLN was associated with significantly slowed hippocampal and cortical atrophy rates in ADRD patients with HHcy, and forebrain parenchymal atrophy rates in CVD patients with HHcy. The present results should be further validated.

Diabetic Microvascular Disease: An Endocrine Society Scientific Statement

Both type 1 and type 2 diabetes adversely affect the microvasculature in multiple organs. Our understanding of the genesis of this injury and of potential interventions to prevent, limit, or reverse injury/dysfunction is continuously evolving. This statement reviews biochemical/cellular pathways involved in facilitating and abrogating microvascular injury. The statement summarizes the types of injury/dysfunction that occur in the three classical diabetes microvascular target tissues, the eye, the kidney, and the peripheral nervous system; the statement also reviews information on the effects of diabetes and insulin resistance on the microvasculature of skin, brain, adipose tissue, and cardiac and skeletal muscle. Despite extensive and intensive research, it is disappointing that microvascular complications of diabetes continue to compromise the quantity and quality of life for patients with diabetes. Hopefully, by understanding and building on current research findings, we will discover new approaches for prevention and treatment that will be effective for future generations.

Effects of horticultural therapy on elderly' health: protocol of a randomized controlled trial

BACKGROUND

Due to a rapidly ageing population in the world, it is increasingly pertinent to promote successful ageing strategies which are cost-effective, easily accessible, and more likely to be acceptable to the elderly. Past research associates exposure to natural environments and horticultural therapy (HT) with positive psychological, social and physical health benefits. This Randomized Controlled Trial (RCT) is designed to evaluate the efficacy of HT in promoting Asian elderly' mental health, cognitive functioning and physical health.

METHODS/DESIGN

70 elderly participants aged 60 to 85 years old will be randomized to participate in either the active horticultural therapy group or be in the waitlist control. Sessions will be weekly for 12 weeks, and monthly for 3 months. Mental health will be assessed through self-reports of depressive and anxiety symptomatology, life satisfaction, social connectedness and psychological well-being, collaborated with immunological markers. Outcome measures of cognitive functioning and physical health include neuropsychological tests of cognitive function and basic health screening. Outcomes will be assessed at baseline, 3 months and 6 months post-intervention.

DISCUSSION

This RCT comprehensively investigates the efficacy of a non-invasive intervention, HT, in enhancing mental health, cognitive functioning and physical health. The results have tremendous potential for supporting future successful ageing programs and applicability to larger populations.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02495194 . Trial registration date: July 13, 2015. Retrospectively registered.

The C677T variant in MTHFR modulates associations between brain integrity, mood, and cognitive functioning in old age

INTRODUCTION

The C677T functional variant in the methylene-tetrahydrofolate reductase (MTHFR) gene leads to reduced enzymatic activity and elevated blood levels of homocysteine. Hyperhomocysteinemia has been linked with higher rates of cardiovascular diseases, cognitive decline, and late-life depression.

METHODS AND MATERIALS

Here, 3D magnetic resonance imaging data was analyzed from 738 individuals (age: 75.5 ± 6.8 years; 438 men/300 women) including 173 Alzheimer's patients, 359 subjects with mild cognitive impairment, and 206 healthy older adults, scanned as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI).

RESULTS

We found that this variant associates with localized brain atrophy, after controlling for age, sex, and dementia status, in brain regions implicated in both intellectual and emotional functioning, notably the medial orbitofrontal cortices. The medial orbitofrontal cortex is involved in the cognitive modulation of emotional processes, and localized atrophy in this region was previously linked with both cognitive impairment and depressive symptoms. Here, we report that increased plasma homocysteine mediates the association between MTHFR genotype and lower medial orbitofrontal volumes, and that these volumes mediate the association between cognitive decline and depressed mood in this elderly cohort. We additionally show that vitamin B12 deficiency interacts with the C677T variant in the etiology of hyperhomocysteinemia.

CONCLUSION

This study sheds light on important relationships between vascular risk factors, age-related cognitive decline, and late-life depression, and represents a significant advance in our understanding of clinically relevant associations relating to MTHFR genotype.

Serum Vitamin B12, Homocysteine and Methylmalonic Acid Levels in Patients With Parenchymal Neuro-Behçet's Syndrome

Objectives

This study aims to investigate the role of serum levels of vitamin B12 (VitB12), homocysteine (Hcy), and methylmalonic acid (MMA) in the development of parenchymal neuro-Behçet's syndrome (NBS) and to compare them with healthy controls and Behçet's syndrome (BS) patients without NBS.

Patients and methods

Serum VitB12, Hcy, and MMA were measured using enzyme-linked immunosorbent assay in 64 patients (36 males, 28 females; mean age 36±8.3 years; range 20 to 56 years) who met the criteria of the International Study Group for Behçet's Disease and 30 matched healthy controls (17 males, 13 females; mean age 35.76±9.6 years; range 20 to 50 years). The study participants were grouped as BS patients with NBS, BS patients without NBS, and healthy controls.

Results

There was no significant difference between the groups regarding serum VitB12, Hcy, and MMA levels (p>0.05). Serum VitB12 levels were below the lower limit and serum Hcy levels were above the upper limit in all participants. MMA levels were normal in all participants. There was no correlation between the serum levels of VitB12, Hcy, and MMA and disease activity (p>0.05).

Conclusion

The results of this study suggest that there is no significant association between VitB12 deficiency and parenchymal NBS. Further studies are needed to investigate the underlying mechanisms of the variable effects of VitB12 deficiency on different clinical manifestations of BS.

Homocysteine and cognition: A systematic review of 111 studies

BACKGROUND

Elevated plasma homocysteine ​​(Hcy) levels have been associated with cognitive dysfunction in a wide range of conditions. The aim of this review is to establish which cognitive domains and populations are the most affected.

METHODS

We systematically review the literature and consider all articles that showed any relationship between plasma Hcy levels and scores achieved on cognitive performance tests in both, the general population and patients suffering from central nervous system disorders and other diseases. When effect sizes were available and combinable, several meta-analyses were performed.

RESULTS

We found 111 pertinent articles. There were 24 cohort studies, 18 randomized trials, 21 case-control studies, and 48 cross-sectional studies. This review reveals a positive trend between cognitive decline and increased plasma Hcy concentrations in general population and in patients with cognitive impairments. Results from the meta-analyses also confirm this trend. Treatment with vitamin supplementation fails to show a reduction in cognitive decline.

DISCUSSION

Further investigations are warranted to clarify this relationship. Earlier detection of the elevated Hcy levels may be an effective intervention to prevent cognitive impairment and dementia.

Analysis of risk factors for vascular cognitive impairment in patients with cerebral infarction

This study aimed to identify risk factors for vascular cognitive impairment (VCI) in cerebral infarction patients. Associations between VCI and age, gender, blood pressure, lipid levels, glycosylated hemoglobin, atrial fibrillation, tobacco smoking, alcohol consumption, homocysteine (Hcy), and High-Sensitivity C-Reactive Protein (HS-CRP) were evaluated in patients with cerebral infarction (n = 300) using single factor analysis and multivariate logistic regression analysis. By single factor analysis, the age, glycosylated hemoglobin, atrial fibrillation, blood pressure, Hcy, HS-CRP, tobacco smoking, and alcohol consumption were significantly associated with VCI in these patients. By multivariate logistic regression analysis, the age, glycosylated hemoglobin, blood pressure, Hcy, and HS-CRP were revealed as independent risk factors. The age, glycosylated hemoglobin, blood pressure, Hcy, and HS-CRP can serve as predictive factors for VCI in patients with cerebral infarction.

Beneficial effects of omega-3 fatty acids and vitamin B12 supplementation on brain docosahexaenoic acid, brain derived neurotrophic factor, and cognitive performance in the second-generation Wistar rats

In vegetarian population, vitamin B12 deficiency coexists with suboptimal levels of omega-3 fatty acids. Studies indicate a need for supplementation/fortification of vitamin B12 and omega-3 fatty acids to reduce the risk of brain disorders. We have described the effects of vitamin B12 and omega-3 fatty acid supplementation on brain development in F1 generation animals. The current study investigates the effects of vitamin B12 and omega-3 fatty acids supplementation on brain function and cognition. Pregnant Wistar rats were assigned the following groups: control, vitamin B12 deficient (BD), vitamin B12 deficient + omega-3 fatty acid (BDO), vitamin B12 supplemented (BS), vitamin B12 supplemented + omega-3 fatty acid (BSO). The same diets were continued for two generations. BDO group showed higher (P < 0.05) levels of BDNF (brain derived neurotrophic factor) and DHA (docosahexaenoic acid) in the cortex and hippocampus as compared with the BD group. The cognitive performance was also normalized in this group. BS showed comparable levels of DHA, BDNF (protein and mRNA), and CREB mRNA (cAMP response element-binding protein) to that of control group while Tropomyosin receptor kinase mRNA levels were higher. The combined vitamin B12 and omega-3 fatty acid supplementation further enhanced the levels of DHA (P < 0.05) and BDNF (P < 0.05) in the hippocampus and CREB mRNA (P < 0.01) in the cortex as compared with BS group. The cognitive performance of these animals was higher (P < 0.05) as compared with BS group. Our data indicates the beneficial effects of vitamin B12 and omega-3 fatty acid supplementation across two generations on brain development and function.

Serum Levels of High-sensitivity C-Reactive Protein at Admission Are More Strongly Associated with Poststroke Depression in Acute Ischemic Stroke than Homocysteine Levels

Inflammatory processes have fundamental roles in depression. The primary purpose of this study was to assess the serum levels of high-sensitivity C-reactive protein (Hs-CRP) and homocysteine (HCY) at admission to the presence of poststroke depression (PSD). From December 2012 to December 2013, first-ever acute ischemic stroke patients who were admitted to the hospital within the first 24 h after stroke onset were consecutively recruited and followed up for 6 months. Serum levels of Hs-CRP and HCY were tested at admission. Based on the symptoms, diagnoses of depression were made in accordance with DSM-IV criteria for depression at 6 months after stroke. Ninety-five patients (42.0%) showed depression (major + minor) at 6 months after admission, and in 69 patients (30.5%), this depression was classified as major. In the 69 patients with major depression, our results showed significantly higher Hs-CRP and HCY levels at admission than patients without major depression. After adjusting all other possible covariates, Hs-CRP and HCY still were independent predicators of PSD with adjusted OR of 1.332 (95% CI, 1.230-1.452; P < 0.001) and 1.138 (95% CI, 1.072-1.274; P < 0.001), respectively. The area under the receiver operating characteristic curve values of Hs-CRP and HCY were 0.765 (95% CI, 0.701-0.9825) and 0.684 (95% CI, 0.610-0.757) for PSD, respectively. The prognostic accuracy of combined model (HCY and Hs-CRP) was higher compared to those biomarkers alone and other markers. Elevated serum levels of Hs-CRP and HCY at admission were found to be associated with depression 6 months after stroke, suggesting that these alterations might participate in the pathophysiology of depression symptoms in stroke patients.

Microstructural white matter tissue characteristics are modulated by homocysteine: a diffusion tensor imaging study

Homocysteine level can lead to adverse effects on the brain white matter through endothelial dysfunction, microstructural inflammation, and neurotoxin effects. Despite previously observed associations between elevated homocysteine and macroscopic structural brain changes, it is still unknown whether microstructural associations of homocysteine on brain tissue properties can be observed in healthy subjects with routine MRI. To this end, we investigated potential relationships between homocysteine levels and microstructural measures computed with diffusion tensor imaging (DTI) in a cohort of 338 healthy participants. Significant positive correlations were observed between homocysteine levels and diffusivity measures in the bilateral temporal WM, the brainstem, and the bilateral cerebellar peduncle. This is the first study demonstrating that DTI is sufficiently sensitive to relate microstructural WM properties to homocysteine levels in healthy subjects.

Correlation of homocysteine metabolic enzymes gene polymorphism and mild cognitive impairment in the Xinjiang Uygur population

Background

The aim of this study was to investigate the genetic polymorphisms in the homocysteine (HCY) metabolic enzymes in the Xinjiang Uygur population who have mild cognitive impairment (MCI).

Material/Methods

Based on the epidemiological investigation, 129 cases of diagnosed Uygur MCI patients and a matched control group with 131 cases were enrolled for analyzing the association between the polymorphisms in the HCY metabolism related genes (C677T, A1298C, and G1968A polymorphisms in MTHFR, as well as the A2756G polymorphism in MS) and MCI by using the SNaPshot method. We then determined the homocysteine level in patients.

Results

In Xinjiang Uygur subjects, the A1298C polymorphisms in MTHFR and the A2756G polymorphisms in the MS gene in the MCI group were different from those in the control group. However, the C677T and G1968A polymorphisms in the MTHFR gene in MCI patients were not different from those in the control group. Multivariate logistic regression showed that, in addition to the well-known risk factors, such as low education level, high cholesterol level, high level of low-density lipoprotein, and high homocysteine levels, the A>G mutation in the MS gene at the rs1805087 locus was another independent risk factor for MCI in the Uyghur MCI population. The risk of MCI in G allele carriers was 2.265 times higher than that in matched control individuals (95% CI: 1.205~4.256, P<0.05).

Conclusions

The genetic polymorphism of HCY metabolizing enzymes is correlated to the occurrence of MCI in the Xinjiang Uygur population. The A2756G polymorphism in the MS gene could be an independent risk factor for MCI in the Xinjiang Uygur population.

Mapping ventricular expansion onto cortical gray matter in older adults

Dynamic changes in the brain's lateral ventricles on magnetic resonance imaging are powerful biomarkers of disease progression in mild cognitive impairment (MCI) and Alzheimer's disease (AD). Ventricular measures can represent accumulation of diffuse brain atrophy with very high effect sizes. Despite having no direct role in cognition, ventricular expansion co-occurs with volumetric loss in gray and white matter structures. To better understand relationships between ventricular and cortical changes over time, we related ventricular expansion to atrophy in cognitively relevant cortical gray matter surfaces, which are more challenging to segment. In ADNI participants, percent change in ventricular volumes at 1-year (N = 677) and 2-year (N = 536) intervals was significantly associated with baseline cortical thickness and volume in the full sample controlling for age, sex, and diagnosis, and in MCI separately. Ventricular expansion in MCI was associated with thinner gray matter in frontal, temporal, and parietal regions affected by AD. Ventricular expansion reflects cortical atrophy in early AD, offering a useful biomarker for clinical trials of interventions to slow AD progression.

Regional brain shrinkage over two years: individual differences and effects of pro-inflammatory genetic polymorphisms

We examined regional changes in brain volume in healthy adults (N=167, age 19-79years at baseline; N=90 at follow-up) over approximately two years. With latent change score models, we evaluated mean change and individual differences in rates of change in 10 anatomically-defined and manually-traced regions of interest (ROIs): lateral prefrontal cortex (LPFC), orbital frontal cortex (OF), prefrontal white matter (PFw), hippocampus (Hc), parahippocampal gyrus (PhG), caudate nucleus (Cd), putamen (Pt), insula (In), cerebellar hemispheres (CbH), and primary visual cortex (VC). Significant mean shrinkage was observed in the Hc, CbH, In, OF, and PhG, and individual differences in change were noted in all regions, except the OF. Pro-inflammatory genetic variants modified shrinkage in PhG and CbH. Carriers of two T alleles of interleukin-1β (IL-1β C-511T, rs16944) and a T allele of methylenetetrahydrofolate reductase (MTHFR C677T, rs1801133) polymorphisms showed increased PhG shrinkage. No effects of a pro-inflammatory polymorphism for C-reactive protein (CRP-286C>A>T, rs3091244) or apolipoprotein (APOE) ε4 allele were noted. These results replicate the pattern of brain shrinkage observed in previous studies, with a notable exception of the LPFC, thus casting doubt on the unique importance of prefrontal cortex in aging. Larger baseline volumes of CbH and In were associated with increased shrinkage, in conflict with the brain reserve hypothesis. Contrary to previous reports, we observed no significant linear effects of age and hypertension on regional brain shrinkage. Our findings warrant further investigation of the effects of neuroinflammation on structural brain change throughout the lifespan.

Cognitive impairment and risk of future stroke: a systematic review and meta-analysis

BACKGROUND

Several studies have assessed the link between cognitive impairment and risk of future stroke, but results have been inconsistent. We conducted a systematic review and meta-analysis of cohort studies to determine the association between cognitive impairment and risk of future stroke.

METHODS

We searched MEDLINE and Embase (1966 to November 2013) and conducted a manual search of bibliographies of relevant retrieved articles and reviews. We included cohort studies that reported multivariable adjusted relative risks and 95% confidence intervals or standard errors for stroke with respect to baseline cognitive impairment.

RESULTS

We identified 18 cohort studies (total 121 879 participants) and 7799 stroke events. Pooled analysis of results from all studies showed that stroke risk increased among patients with cognitive impairment at baseline (relative risk [RR] 1.39, 95% confidence interval [CI] 1.24-1.56). The results were similar when we restricted the analysis to studies that used a widely adopted definition of cognitive impairment (i.e., Mini-Mental State Examination score < 25 or nearest equivalent) (RR 1.64, 95% CI 1.46-1.84). Cognitive impairment at baseline was also associated with an increased risk of fatal stroke (RR 1.68, 95% CI 1.21-2.33) and ischemic stroke (RR 1.65, 95% CI 1.41-1.93).

INTERPRETATION

Baseline cognitive impairment was associated with a significantly higher risk of future stroke, especially ischemic and fatal stroke.

Small vessel disease and memory loss: what the clinician needs to know to preserve patients' brain health

Small vessel disease (SVD) in the brain manifests in the periventricular and deep white matter and radiographically is described as "leukoaraiosis". It is increasingly recognized as a cause of morbidity from middle age onward and this clinical relevance has paralleled advances in the field of neuroradiology. Overall, SVD is a heterogenous group of vascular disorders that may be asymptomatic, or a harbinger of many conditions that jeopardize brain health. Management and prevention focuses on blood pressure control, lifestyle modification, and symptomatic treatment.