Scientometric Research and Critical Analysis of Gait and Balance in Older Adults

Gait and balance have emerged as a critical area of research in health technology. Gait and balance studies have been affected by the researchers' slow follow-up of research advances due to the absence of visual inspection of the study literature across decades. This study uses advanced search methods to analyse the literature on gait and balance in older adults from 1993 to 2022 in the Web of Science (WoS) database to gain a better understanding of the current status and trends in the field for the first time. The study analysed 4484 academic publications including journal articles and conference proceedings on gait and balance in older adults. Bibliometric analysis methods were applied to examine the publication year, number of publications, discipline distribution, journal distribution, research institutions, application fields, test methods, analysis theories, and influencing factors in the field of gait and balance. The results indicate that the publication of relevant research documents has been steadily increasing from 1993 to 2022. The United States (US) exhibits the highest number of publications with 1742 articles. The keyword "elderly person" exhibits a strong citation burst strength of 18.04, indicating a significant focus on research related to the health of older adults. With a burst factor of 20.46, Harvard University has made impressive strides in the subject. The University of Pittsburgh displayed high research skills in the area of gait and balance with a burst factor of 7.7 and a publication count of 103. The research on gait and balance mainly focuses on physical performance evaluation approaches, and the primary study methods include experimental investigations, computational modelling, and observational studies. The field of gait and balance research is increasingly intertwined with computer science and artificial intelligence (AI), paving the way for intelligent monitoring of gait and balance in the elderly. Moving forward, the future of gait and balance research is anticipated to highlight the importance of multidisciplinary collaboration, intelligence-driven approaches, and advanced visualization techniques.

New horizons in cognitive and functional impairment as a consequence of cerebral small vessel disease

Cerebral small vessel disease (cSVD) is a frequent finding in imaging of the brain in older adults, especially in the concomitance of cardiovascular disease risk factors. Despite the well-established link between cSVD and (vascular) cognitive impairment (VCI), it remains uncertain how and when these vascular alterations lead to cognitive decline. The extent of acknowledged markers of cSVD is at best modestly associated with the severity of clinical symptoms, but technological advances increasingly allow to identify and quantify the extent and perhaps also the functional impact of cSVD more accurately. This will facilitate a more accurate diagnosis of VCI, against the backdrop of concomitant other neurodegenerative pathology, and help to identify persons with the greatest risk of cognitive and functional deterioration. In this study, we discuss how better assessment of cSVD using refined neuropsychological and comprehensive geriatric assessment as well as modern image analysis techniques may improve diagnosis and possibly the prognosis of VCI. Finally, we discuss new avenues in the treatment of cSVD and outline how these contemporary insights into cSVD can contribute to optimise screening and treatment strategies in older adults with cognitive impairment and multimorbidity.

Impact of White Matter Hyperintensity and Age on Gait Parameters in Patients With Cerebral Small Vessel Disease

OBJECTIVES

This study aimed to investigate the effect of white matter hyperintensity (WMH), a common cerebral small vessel disease (CSVD) imaging marker, and age on gait parameters in middle-aged and geriatric populations.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

A total of 1076 participants (62.9% female; age 61.0 ± 9.3 years), who visited the neurology clinic or obtained a physical check-up from the Affiliated Hospital of Guizhou Medical University. In total, 883 patients with WMH and 193 healthy controls were included in this study.

METHODS

The Fazekas scores of patients with CSVD were used to assess the burden of WMH. Based on the Fazekas scores, all participants were divided into 4 groups: 553 patients with Fazekas I, 257 patients with Fazekas II, 73 patients with Fazekas III, and 193 controls. Gait parameters, including step speed, frequency, length, width, stance time, and swing time, were quantitatively assessed using a vision-based artificial intelligence gait analyzer (SAIL system). The relationships among the Fazekas scores, age, and gait parameters were analyzed.

RESULTS

Step speed, step length, step width, stance time, and swing time were significantly different among the 4 groups. Furthermore, Fazekas scores and age were both associated with gait parameters, including step speed, step length, stance time, and swing time. The Fazekas scores were associated with step width, whereas age was not. Age was associated with step frequency, whereas Fazekas scores were not.

CONCLUSIONS AND IMPLICATIONS

Fazekas score and age are useful for evaluating gait parameters in patients with CSVD. Emerging WMH (such as Fazekas Ⅰ) could be a clinical warning sign of gait disturbance in a geriatric population.

Association between white matter hyperintensity volume and social functioning limitations among stroke survivors

OBJECTIVE

Existing literature on white matter hyperintensity volume (WMHV) in stroke patients has rarely focused on post-stroke outcomes related to social functioning limitations, such as transportation, social interaction, food preparation, grocery shopping, and housekeeping. Using prospective data from the VITamin D and OmegA-3 TriaL (VITAL) study, we evaluated the association between WMHV and social functioning limitations among 151 ischemic stroke patients.

MATERIALS AND METHODS

WMHV was ascertained from magnetic resonance imaging (MRI) collected at the time of the stroke event using a validated semiautomated method, and social functioning limitations were assessed using a stroke outcomes questionnaire administered a median of 1.25 years after the date of the MRI scan. Logistic regression was used to explore the association between WMHV and social functioning limitations.

RESULTS

After adjusting for age and sex, a statistically significant association was found between WMHV and limitations in social interaction (OR=2.82; 95% CI: 1.21-7.55). Increased risks were seen for limitations related to food preparation (OR=2.06; 95% CI: 0.99-4.54), transportation (OR=1.39; 95% CI: 0.85-2.27), and housekeeping (OR=1.37; 95% CI: 0.91-2.11); however, the associations did not reach statistical significance. We observed no association between WMHV and limitations in grocery shopping (OR=1.08; 95% CI: 0.61-1.89).

CONCLUSIONS

Future studies are needed to further explore the biological mechanisms underlying the relationship with limitations in social interaction and to replicate our findings using a larger and more diverse study sample.

Leukoaraiosis severity and post-reperfusion outcomes in acute ischaemic stroke: A meta-analysis

OBJECTIVES

Severity of leukoaraiosis may mediate outcomes after reperfusion therapy in acute ischaemic stroke (AIS) patients. However, the level of the association remains poorly understood. We performed a meta-analysis to investigate the impact of leukoaraiosis severity on functional outcome, survival, haemorrhagic complications, and procedural success in AIS patients treated with intravenous thrombolysis and/or endovascular thrombectomy.

MATERIALS AND METHODS

PubMed, EMBASE and the Cochrane library were searched for studies on leukoaraiosis in AIS receiving reperfusion therapy. A random-effects meta-analysis was conducted for post-reperfusion outcomes in AIS patients with absent-to-mild leukoaraiosis and moderate-to-severe leukoaraiosis. The strength of association between moderate-to-severe leukoaraiosis and poor outcomes was quantified using odds ratios (OR).

RESULTS

A total of 15 eligible studies involving 6460 patients (1451 with moderate-to-severe leukoaraiosis and 5009 with absent-to-mild leukoaraiosis) were included in the meta-analysis. Moderate-to-severe leukoaraiosis was significantly associated with poor 90-day functional outcome (OR 3.16; 95% confidence interval (CI) 2.69-3.72; p < .0001), 90-day mortality (OR 3.11; 95% CI 2.27-4.26; p < .0001) and increased risk of symptomatic intracerebral haemorrhage (OR 1.69; 95% CI 1.24-2.32; p = .001) after reperfusion therapy. Overall, no significant association of leukoaraiosis severity with haemorrhagic transformation (HT) and angiographic recanalization status were observed. However, subgroup analysis revealed a significant association of WML severity with HT in patients receiving EVT.

CONCLUSION

Leukoaraiosis is a useful prognostic biomarker in AIS. Patients with moderate-to-severe leukoaraiosis on baseline imaging are likely to have worse clinical and safety outcomes after reperfusion therapy.

Five years of exercise intervention at different intensities and development of white matter hyperintensities in community dwelling older adults, a Generation 100 sub-study

We investigated if a five-year supervised exercise intervention with moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) versus control; physical activity according to national guidelines, attenuated the growth of white matter hyperintensities (WMH). We hypothesized that supervised exercise, in particular HIIT, reduced WMH growth. Older adults from the general population participating in the RCT Generation 100 Study were scanned at 3T MRI at baseline (age 70–77), and after 1-, 3- and 5-years. At each follow-up, cardiorespiratory fitness was measured with ergospirometry, and physical activity plus clinical data collected. Manually delineated total WMH, periventricular (PWMH), deep (DWMH), and automated total white matter hypointensity volumes were obtained. No group by time interactions were present in linear mixed model analyses with the different WMH measurements as outcomes. In the combined exercise (MICT&HIIT) group, a significant group by time interaction was uncovered for PWMH volume, with a larger increase in the MICT&HIIT group. Cardiorespiratory fitness at the follow-ups or change in cardiorespiratory fitness over time were not associated with any WMH measure. Contrary to our hypothesis, taking part in MICT or HIIT over a five-year period did not attenuate WMH growth compared to being in a control group following national physical activity guidelines.

Determinants of Physical Activity at 90 Days After Acute Stroke or Transient Ischemic Attack in Patients With Home Discharge: A Pilot Study

The aim was to identify the barriers to achieving premorbid physical activity in patients with home discharge after acute minor stroke or transient ischemic attack. Fifty-six patients (median age, 72 years) were analyzed. We assessed total physical activity in the premorbid condition and at 90 days after onset using the International Physical Activity Questionnaire. The patients were divided into two groups according to changes in total physical activity until 90 days after onset: decreased activity (n = 16) and nondecreased activity (n = 40) groups. Outcome measures were examined at discharge. The decreased activity group took significantly longer to perform the timed up and go test (median, 7.19 vs. 6.52 s) and contained more apathetic patients (44% vs. 15%). Apathy at discharge (relative risk 6.05, 95% confidence interval [1.33, 27.6]) was a significant determinant of decreased physical activity. Apathy is a barrier to the restoration of premorbid physical activity in stroke survivors.

Subclinical Atherosclerosis, Vascular Risk Factors, and White Matter Alterations in Diffusion Tensor Imaging Findings of Older Adults With Cardiometabolic Diseases

White matter abnormalities may reflect cerebral microvessel disease. Diffusion tensor imaging (DTI) can help detect early changes in white matter integrity in each tract. However, studies investigating the relationship between subclinical atherosclerosis markers and white matter alterations in DTI findings are limited. This study aimed to examine associations between cardiovascular risk factors and indices of subclinical atherosclerosis-ankle brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and carotid artery intima-media thickness (IMT)-and altered white matter integrity in older patients. A total of 224 patients (aged ≥65 years) with cardiometabolic disease who underwent magnetic resonance imaging (MRI) and either plethysmography or cervical ultrasound at the start of the 3-year observational study period were included in this study. We measured fractional anisotropy (FA) and mean diffusivity (MD), which are indices of white matter integrity in seven white matter tracts. In a univariate analysis, lower ABI and higher baPWV values were associated with FA or MD abnormalities in several tracts, whereas IMT was scarcely associated with such change. In addition, high blood pressure and glycoalbumin/glycohemoglobin ratio (GA/HbA1c) and low body mass index (BMI) and triglyceride (TG) levels were associated with FA or MD abnormalities. In a multivariate analysis adjusted for age, sex, BMI, diastolic blood pressure, TG, and GA/HbA1c, the associations between ABI and FA or MD remained in all of either side of the following tracts: anterior thalamic radiation, forceps minor, inferior frontooccipital fasciculus (p < 0.001 for all) and superior longitudinal fasciculus (SLF; p < 0.05), whereas most of those between baPWV and FA or MD disappeared except for SLF (p < 0.05). These results indicate that low ABI could be an indicator of white matter abnormalities.

Deep white matter hyperintensity is associated with the dilation of perivascular space

Understanding the pathophysiology of white matter hyperintensity (WMH) is necessary to reduce its harmfulness. Dilated perivascular space (PVS) had been found related to WMH. In the present study, we aimed to examine the topological connections between WMH and PVS, and to investigate whether increased interstitial fluid mediates the correlation between PVS and WMH volumes. One hundred and thirty-six healthy elder subjects were retrospectively included from a prospectively collected community cohort. Sub-millimeter T2 weighted and FLAIR images were acquired for assessing the association between PVS and WMH. Diffusion tensor imaging and free-water (FW) analytical methods were used to quantify white matter free water content, and to explore whether it mediates the PVS-WMH association. We found that most (89%) of the deep WMH lesions were spatially connected with PVS, exhibiting several interesting topological types. PVS and WMH volumes were also significantly correlated (r = 0.222, p < 0.001). FW mediated this association in the whole sample (β = 0.069, p = 0.037) and in subjects with relatively high WMH load (β = 0.118, p = 0.006). These findings suggest a tight association between PVS dilation and WMH formation, which might be linked by the impaired glymphatic drainage function and accumulated local interstitial fluid.

The Association of White Matter Hyperintensities with Frailty in Patients with Very Mild to Moderate Alzheimer's Disease

BACKGROUND

Frailty, one of serious global health problems in the elderly, is a growing concern in patients with Alzheimer's disease (AD) because of its high prevalence in AD and its impact on the prognosis.

OBJECTIVE

To investigate the quantitative association between white matter hyperintensities (WMH) and frailty in AD.

METHODS

A total of 144 outpatients were included. All subjects were evaluated by using Korean version of the CERAD assessment battery and diagnosed very mild to moderate AD. WMH volume was calculated using automated segmentation analysis from the 3D MRI image and further partitioned according to the distance from the ventricular surface. Using the Korean Frailty Index, prefrailty was defined by the scores of 3 and 4 and frailty by the score of 5 and higher.

RESULTS

In total, 23.6%were frailty, 32.6%were pre-frailty, and 43.8%were classified as a robust group. The frailty group had higher WMH volume compared to the robust group (p = 0.02), and these trends remained significant after linear regression analyses. According to the subclassification of WMH, using the robust group as a reference, total WMH (OR = 6.297, p = 0.013, 95%CI = 1.463-27.114), juxtaventricular WMH (OR = 12.955, p = 0.014, 95%CI = 1.687-99.509), and periventricular WMH (OR = 3.382, p = 0.025, 95%CI = 1.163-9.8531) volumes were associated with frailty, but deep WMH volume was not.

CONCLUSIONS

A quarter of patients with very mild to moderate AD is suffering from frailty. Our study provides the evidence of a cross-sectional relationship between WMH volume and frailty, and there is a difference in the association between the subclassification of WMH volume and frailty.

The Effects of Tau, Amyloid, and White Matter Lesions on Mobility, Dual Tasking, and Balance in Older People

Background

This study aimed to investigate whether white matter lesions (WML), β-amyloid-, and tau pathologies are independently associated with mobility, dual tasking, and dynamic balance performance in older nondemented individuals.

Methods

We included 299 older people (mean, SD, age: 71.8, 5.6 years) from the Swedish BioFINDER study, whereof 175 were cognitively unimpaired and 124 had mild cognitive impairment (MCI). In multivariable regression analyses, dependent variables included mobility (Timed Up & Go [TUG]), dual tasking (TUG with a simultaneous subtraction task, that is, TUG-Cog, as well as dual task cost), and balance (Figure-of-eight). The analyses were controlled for age, sex, education, diagnosis (ie, MCI), and comorbidity (stroke, diabetes, and ischemic heart disease). Independent variables included WML volume, and measures of β-amyloid (abnormal cerebrospinal fluid [CSF] Aβ42/40 ratio) and tau pathology (CSF phosphorylated tau [p-tau]).

Results

Multivariable regression analyses showed that an increased WML volume was independently associated with decreased mobility, that is, TUG (standardized β = 0.247; p < .001). Tau pathology was independently associated with dual tasking both when using the raw data of TUG-Cog (β = 0.224; p = .003) and the dual-task cost (β= −0.246; p = .001). Amyloid pathology was associated with decreased balance, that is, Figure-of-eight (β = 0.172; p = .028). The independent effects of WML and tau pathology were mainly observed in those with MCI, which was not the case for the effects of amyloid pathology on balance.

Conclusions

Common brain pathologies have different effects where WML are independently associated with mobility, tau pathology has the strongest effect on dual tasking, and amyloid pathology seems to be independently associated with balance. Although these novel findings need to be confirmed in longitudinal studies, they suggest that different brain pathologies have different effects on mobility, balance, and dual-tasking in older nondemented individuals.

Emerging role of white matter lesions in cerebrovascular disease

White matter lesions have been implicated in the setting of stroke, dementia, intracerebral haemorrhage, several other cerebrovascular conditions, migraine, various neuroimmunological diseases like multiple sclerosis, disorders of metabolism, mitochondrial diseases and others. While much is understood vis a vis neuroimmunological conditions, our knowledge of the pathophysiology of these lesions, and their role in, and implications to, management of cerebrovascular diseases or stroke, especially in the elderly, are limited. Several clinical assessment tools are available for delineating white matter lesions in clinical practice. However, their incorporation into clinical decision-making and specifically prognosis and management of patients is suboptimal for use in standards of care. This article sought to provide an overview of the current knowledge and recent advances on pathophysiology, as well as clinical and radiological assessment, of white matter lesions with a focus on its development, progression and clinical implications in cerebrovascular diseases. Key indications for clinical practice and recommendations on future areas of research are also discussed. Finally, a conceptual proposal on putative mechanisms underlying pathogenesis of white matter lesions in cerebrovascular disease has been presented. Understanding of pathophysiology of white matter lesions and how they mediate outcomes is important to develop therapeutic strategies.

The Clinical Characteristics of Patients with Pre-Existing Leukoaraiosis Compared to Those Without Leukoaraiosis in Acute Ischemic Stroke

BACKGROUND

Leukoaraiosis (LA) is a finding in the elderly, that might be asymptomatic or can impact their motor and cognitive functions. We studied the presence of LA in the MRI of patients with AIS and its impact on functional outcome at 3 months.

METHODS

500 consecutive patients diagnosed as AIS were enrolled. Medical history included pre-medication by antiplatelets or statins, and vascular risk factors were reported by history and laboratory investigations. Severity of stroke was assessed by NIHSS and stroke outcome was evaluated on discharge and at 3 months by modified Rankin scale (mRS). LA was diagnosed by MRI-FLAIR sequence and delineated from acute infarction by diffusion-weighted image. And accordingly, patients were divided into group A (absent LA) and group B (present LA).

RESULTS

460 patients completed the study, with 53% of patients on antiplatelet therapy and 11.7% on statins prior to stroke. The percentage of patients with LA was significantly more than those without LA. Patients with LA showed a significantly higher age, more frequent and longer duration of diabetes and hypertension, ischemic heart disease, previous stroke/TIA and antiplatelet intake. Microbleeds were more and mRS was worse in LA group.

CONCLUSION

The presence of LA in the background MRI of AIS patients is accompanied by the presence of more risk factors, and unfavorable outcome. Pre-medication with antiplatelets did not prevent the incidence of a new stroke especially in LA group. This might necessitate the identification of some medication for secondary prevention in patients with small vessel disease.

Gait Impairment and Upper Extremity Disturbance Are Associated With Total Magnetic Resonance Imaging Cerebral Small Vessel Disease Burden

Background and Purpose: Cerebral small vessel disease (cSVD)—including white matter hyperintensities (WMHs), cerebral microbleeds (CMBs), lacunes, and enlarged perivascular spaces (EPVS)—is related to gait impairment. However, the association between the total magnetic resonance imaging (MRI) cSVD burden and gait and upper extremity function remains insufficiently investigated. This study aimed to assess the correlation between the total MRI cSVD burden score and gait impairment as well as upper extremity impairment.

Method: A total of 224 participants underwent MRI scans, and the presence of lacunes, WMHs, CMBs, and EPVS was evaluated and recorded as a total MRI cSVD burden score (range 0–4). Gait was assessed by 4-m walkway, Tinetti, Timed Up and Go (TUG), and Short Physical Performance Battery (SPPB) tests. Upper extremity function was assessed by 10-repeat hand pronation-supination time, 10-repeat finger-tapping time, and 10-repeat hand opening and closing time.

Result: The mean age of the 224 participants was 60.6 ± 10.5 years, and 64.3% were men. Independent of age, sex, height, and vascular risk factors, multivariable linear regression analyses showed that a higher total MRI cSVD burden score was related to a shorter stride length, wider step width, higher cadence, and poorer performance on the Tinetti, TUG, and SPPB tests and upper extremity tests (all P < 0.05).

Conclusion: Total MRI cSVD burden was associated with gait impairment and upper extremity disturbances, suggesting that total MRI cSVD burden might contribute to motor function decline. Longitudinal studies are required to determine whether there is a causal relationship between total MRI cSVD burden and motor function decline.

Modeling subcortical ischemic white matter injury in rodents: unmet need for a breakthrough in translational research

Subcortical ischemic white matter injury (SIWMI), pathological correlate of white matter hyperintensities or leukoaraiosis on magnetic resonance imaging, is a common cause of cognitive decline in elderly. Despite its high prevalence, it remains unknown how various components of the white matter degenerate in response to chronic ischemia.This incomplete knowledge is in part due to a lack of adequate animal model. The current review introduces various SIWMI animal models and aims to scrutinize their advantages and disadvantages primarily in regard to the pathological manifestations of white matter components. The SIWMI animal models are categorized into 1) chemically induced SIWMI models, 2) vascular occlusive SIWMI models, and 3) SIWMI models with comorbid vascular risk factors. Chemically induced models display consistent lesions in predetermined areas of the white matter, but the abrupt evolution of lesions does not appropriately reflect the progressive pathological processes in human white matter hyperintensities. Vascular occlusive SIWMI models often do not exhibit white matter lesions that are sufficiently unequivocal to be quantified. When combined with comorbid vascular risk factors (specifically hypertension), however, they can produce progressive and definitive white matter lesions including diffuse rarefaction, demyelination, loss of oligodendrocytes, and glial activation, which are by far the closest to those found in human white matter hyperintensities lesions. However, considerable surgical mortality and unpredictable natural deaths during a follow-up period would necessitate further refinements in these models. In the meantime, in vitro SIWMI models that recapitulate myelinated white matter track may be utilized to study molecular mechanisms of the ischemic white matter injury. Appropriate in vivo and in vitro SIWMI models will contribute in a complementary manner to making a breakthrough in developing effective treatment to prevent progression of white matter hyperintensities.

Cerebral Amyloid-β Deposition Is Associated with Impaired Gait Speed and Lower Extremity Function

BACKGROUND

Impaired physical function (i.e., slowing of gait, muscle weakness, and poor mobility) is common in older adults with cognitive impairment and dementia. Evidence suggests that cerebral small vessel disease, specifically white matter lesions (WMLs), is associated with impaired physical function, but little research has been conducted to understand the specific role of Alzheimer's disease pathology in physical outcomes.

OBJECTIVE

The objective of this study was to examine the association between cerebral amyloid-β (Aβ) deposition and physical function in people with cognitive impairment.

METHODS

Thirty participants completed an 11C Pittsburgh compound B (PIB) position emission tomography (PET) scan to quantify global Aβ deposition using standardized uptake value ratio (SUVR). We assessed usual gait speed, muscle strength of the lower extremities, balance, and functional mobility using the Short Physical Performance Battery (SPPB) and the Timed Up and Go Test (TUGT). Multiple linear regression analyses examined the association between Aβ and each measure of physical function, adjusting for age, body mass index, and WML load.

RESULTS

Global PIB SUVR was significantly associated with usual gait speed (β= -0.52, p = 0.01) and SPPB performance (β= -0.47, p = 0.02), such that increased Aβ deposition was associated with reduced performance on both measures. Global PIB SUVR was not significantly associated with TUGT performance (β= 0.32, p = 0.08).

CONCLUSIONS

Cerebral Aβ deposition is associated with reduced gait speed, muscle strength, and balance in older adults with cognitive impairment independent of WML load. However, Aβ deposition was not associated with functional mobility.

Common Genetic Variation Indicates Separate Causes for Periventricular and Deep White Matter Hyperintensities

BACKGROUND AND PURPOSE

Periventricular white matter hyperintensities (WMH; PVWMH) and deep WMH (DWMH) are regional classifications of WMH and reflect proposed differences in cause. In the first study, to date, we undertook genome-wide association analyses of DWMH and PVWMH to show that these phenotypes have different genetic underpinnings.

METHODS

Participants were aged 45 years and older, free of stroke and dementia. We conducted genome-wide association analyses of PVWMH and DWMH in 26,654 participants from CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology), ENIGMA (Enhancing Neuro-Imaging Genetics Through Meta-Analysis), and the UKB (UK Biobank). Regional correlations were investigated using the genome-wide association analyses -pairwise method. Cross-trait genetic correlations between PVWMH, DWMH, stroke, and dementia were estimated using LDSC.

RESULTS

In the discovery and replication analysis, for PVWMH only, we found associations on chromosomes 2 (NBEAL), 10q23.1 (TSPAN14/FAM231A), and 10q24.33 (SH3PXD2A). In the much larger combined meta-analysis of all cohorts, we identified ten significant regions for PVWMH: chromosomes 2 (3 regions), 6, 7, 10 (2 regions), 13, 16, and 17q23.1. New loci of interest include 7q36.1 (NOS3) and 16q24.2. In both the discovery/replication and combined analysis, we found genome-wide significant associations for the 17q25.1 locus for both DWMH and PVWMH. Using gene-based association analysis, 19 genes across all regions were identified for PVWMH only, including the new genes: CALCRL (2q32.1), KLHL24 (3q27.1), VCAN (5q27.1), and POLR2F (22q13.1). Thirteen genes in the 17q25.1 locus were significant for both phenotypes. More extensive genetic correlations were observed for PVWMH with small vessel ischemic stroke. There were no associations with dementia for either phenotype.

CONCLUSIONS

Our study confirms these phenotypes have distinct and also shared genetic architectures. Genetic analyses indicated PVWMH was more associated with ischemic stroke whilst DWMH loci were implicated in vascular, astrocyte, and neuronal function. Our study confirms these phenotypes are distinct neuroimaging classifications and identifies new candidate genes associated with PVWMH only.

Cumulative Blood Pressure Exposure, Basal Ganglia, and Thalamic Morphology in Midlife

High blood pressure (BP) negatively affects brain structure and function. Hypertension is associated with white matter hyperintensities, cognitive and mobility impairment in late-life. However, the impact of BP exposure from young adulthood on brain structure and function in mid-life is unclear. Identifying early brain structural changes associated with BP exposure, before clinical onset of cognitive dysfunction and mobility impairment, is essential for understanding mechanisms and developing interventions. We examined the effect of cumulative BP exposure from young adulthood on brain structure in a substudy of 144 (61 female) individuals from the CARDIA (Coronary Artery Risk Development in Young Adults) study. At year 30 (Y₃₀, ninth visit), participants (56±4 years old) completed brain magnetic resonance imaging and gait measures (pace, rhythm, and postural control). Cumulative systolic and diastolic BP (cumulative systolic blood pressure, cDBP) over 9 visits were calculated, multiplying mean values between 2 consecutive visits by years between visits. Surface-based analysis of basal ganglia and thalamus was achieved using FreeSurfer-initiated Large Deformation Diffeomorphic Metric Mapping. Morphometric changes were regressed onto cumulative BP to localize regions of shape variation. Y₃₀ white matter hyperintensity volumes were small and positively correlated with cumulative BP but not gait. Negative morphometric associations with cumulative systolic blood pressure were seen in the caudate, putamen, nucleus accumbens, pallidum, and thalamus. A concave right medial putamen shape mediated the relationship between cumulative systolic blood pressure and stride width. Basal ganglia and thalamic morphometric changes, rather than volumes, may be earlier manifestation of gray matter structural signatures of BP exposure that impact midlife gait.

Diabetes as a risk factor for Alzheimer's disease in the Middle East and its shared pathological mediators

The incidence of Alzheimer's disease (AD) has risen exponentially worldwide over the past decade. A growing body of research indicates that AD is linked to diabetes mellitus (DM) and suggests that impaired insulin signaling acts as a crucial risk factor in determining the progression of this devastating disease. Many studies suggest people with diabetes, especially type 2 diabetes, are at higher risk of eventually developing Alzheimer's dementia or other dementias. Despite nationwide efforts to increase awareness, the prevalence of Diabetes Mellitus (DM) has risen significantly in the Middle East and North African (MENA) region which might be due to rapid urbanization, lifestyle changes, lack of physical activity and rise in obesity. Growing body of evidence indicates that DM and AD are linked because both conditions involve impaired glucose homeostasis and altered brain function. Current theories and hypothesis clearly implicate that defective insulin signaling in the brain contributes to synaptic dysfunction and cognitive deficits in AD. In the periphery, low-grade chronic inflammation leads to insulin resistance followed by tissue deterioration. Thus insulin resistance acts as a bridge between DM and AD. There is pressing need to understand on how DM increases the risk of AD as well as the underlying mechanisms, due to the projected increase in age related disorders. Here we aim to review the incidence of AD and DM in the Middle East and the possible link between insulin signaling and ApoE carrier status on Aβ aggregation, tau hyperphosphorylation, inflammation, oxidative stress and mitochondrial dysfunction in AD. We also critically reviewed mutation studies in Arab population which might influence DM induced AD. In addition, recent clinical trials and animal studies conducted to evaluate the efficiency of anti-diabetic drugs have been reviewed.

Physical signs of canine cognitive dysfunction

Physical disturbances are common in dogs with canine cognitive dysfunction (CCD). However, the relation between these physical disturbances and CCD has not been clarified. The aim of this study was to clarify the physical disturbances in CCD by questionnaire survey. The questionnaire consisted of items of general information, physical disturbances (gait and posture abnormalities, and deteriorating perception) and a CCD assessment scale named the CCD rating scale (CCDR). The survey was conducted toward owners of dogs aged 10 years or older in two ways: A web-based (Web survey) and a paper-based (Paper survey) survey. To determine which physical disturbances were associated with CCD, ordinal logistic regression analyzes were performed. Through the Web survey, 726 valid responses were obtained, and the test results revealed that vision impairment, smell disturbance, tremor, swaying or falling and head ptosis were significantly associated with CCD. These items, except for head ptosis, were also significantly associated with, or tended to be associated with, CCD in 103 valid responses to the Paper survey. The prevalence of CCD was increased in the elderly dog population, especially in dogs aged 16 years or older. In contrast, physical signs gradually increased from 10 years of age. These results suggest that physical disturbances may appear in the early stages of CCD. In conclusion, the present study revealed new clinical signs of CCD linked to physical disturbances and suggested that these signs could be useful for detecting early stage of CCD.

Predictors of gait speed and its change over three years in community-dwelling older people

We aimed to assess whether and how changes in brain volume and increases in white matter hyperintensity (WMH) volume over three years predict gait speed and its change independently of demographics, vascular risk factors and physical status. We analyzed 443 individuals from the Lothian Birth Cohort 1936, at mean age 73 and 76 years. Gait speed at age 76 was predicted by age, grip strength and body mass index at mean age 73, three-year brain volume decrease and WMH volume increase, explaining 26.1% of variance. Decline in gait speed to age 76 was predicted by the same five variables explaining 40.9% of variance. In both analyses, grip strength and body mass index explained the most variance. A clinically significant decline in gait speed (≥ 0.1 m/s per year) occurred in 24.4%. These individuals had more structural brain changes. Brain volume and WMH changes were independent predictors of gait dysfunction and its three-year change, but the impact of malleable physical factors such as grip strength or body mass index was greater.

Cerebrovascular pathology presenting as corticobasal syndrome: An autopsy case series of "vascular CBS"

BACKGROUND

The corticobasal syndrome (CBS) is heterogeneous in terms of postmortem neuropathology. While it has been previously studied with antemortem neuroimaging, clinicopathologic features of corticobasal syndrome associated with cerebrovascular pathology (vascular CBS) have yet to be reported.

METHODS

To identify vascular CBS, we searched the database of the CurePSP Brain Bank for patients with a clinical diagnosis of CBS who failed to meet neuropathologic criteria for corticobasal degeneration (CBD) or other neurodegenerative disease processes, but who had significant cerebrovascular pathology. Hemibrains were assessed macroscopically and processed for histological assessment. Medical records were reviewed to characterize clinical features of vascular CBS.

RESULTS

Of 217 patients with an antemortem diagnosis of CBS, we identified three patients with vascular CBS. Multiple infarcts in the watershed regions (frontal lobe and motor cortex), periventricular white matter, thalamus, and basal ganglia were observed in two patients. One patient had no cortical infarcts, but had multiple white matter infarcts and corticospinal tract degeneration. All were clinically thought to have CBS based on progressive asymmetric motor symptoms, including rigidity and apraxia, as well as cognitive impairment. Antemortem imaging studies showed findings of chronic cerebrovascular disease, with infarcts or white matter pathology.

CONCLUSIONS

This autopsy study of vascular CBS shows that, while rare, cerebrovascular pathology involving the frontal lobe, white matter tracts, basal ganglia, thalamus, and corticospinal tract can underlie clinical features suggestive of CBS. When neuroimaging suggests an alternative explanation, including chronic infarcts in critical regions, caution is merited in considering CBD as the underlying pathology.

Brain White Matter: A Substrate for Resilience and a Substance for Subcortical Small Vessel Disease

Age-related brain white matter disease is a form of small vessel disease (SVD) that may be associated with lacunar and other small subcortical infarcts, cerebral microbleeds, and perivascular spaces. This common form of cerebrovascular disease may manifest clinically as cognitive impairment of varying degrees and difficulty with mobility. Whereas some persons show cognitive decline and mobility failure when there are brain white matter hyperintensities (WMH) and acute stroke, others recover, and not everyone with brain white matter disease is disabled. Thus, repair or compensation of brain white matter may be possible, and furthermore, certain vascular risks, such as raised blood pressure, are targets for prevention of white matter disease or are administered to reduce the burden of such disease. Vascular risk modification may be useful, but alone may not be sufficient to prevent white matter disease progression. In this chapter, we specifically focus on WMH of vascular origin and explore white matter development, plasticity, and enduring processes of myelination across the health span in the context of experimental and human data, and compare and contrast resilient brain white matter propensity to a diseased white matter state. We conclude with thoughts on novel ways one might study white matter resilience, and predict future healthy cognitive and functional outcomes.

Hypermethylation of ERа-A gene and high serum homocysteine level are correlated with cognitive impairment in white matter hyperintensity patients

OBJECTIVE

To investigate the methylation status in promoter region of estrogen receptor alpha (ERа)-A gene and its relation with plasma homocysteine (Hcy) level and cognitive impairment in white matter hyperintensity (WMH) patients.

PATIENTS AND METHODS

210 patients aged 65 and older were selected. The methylation status of CpG islands in ERа-A gene promoter was analyzed by nested methylation-specific PCR. Serum Hcy and estradiol levels were measured by enzyme-linked immunosorbent assay. Cognitive function were evaluated using minimum mental state examination, the montreal cognitive assessment, Stroop color-word test, symbol digit modalities, trail making test B and instrumental activities of daily living (IADL). The severity of WMH was evaluated with the Fazekas scale by brain magnetic resonance imaging.

RESULTS

We found a significant association between the severity of WMH and CpG island methylation of ERа-A gene (P < 0.05). Multiple regression analysis showed that serum Hcy level, methylation of ERа-A gene and WMH severity were significant determining factors for cognitive impairment (P < 0.05). The spearman rank correlation analysis showed a significant correlation of methylation of ERа-A gene with serum Hcy level, WMH severity, cognitive function and IADL status (P < 0.05).

CONCLUSION

Methylation of ERа-A gene promoter has a high frequency in WMH patients with cognitive impairment and is correlated with high plasma Hcy level.

Frailty and Cerebral Small Vessel Disease: A Cross-Sectional Analysis of the Tasmanian Study of Cognition and Gait (TASCOG)

Background

Frailty is a prevalent geriatric condition associated with poor health outcomes. The pathogenesis of frailty is incompletely understood. We aimed to evaluate the relationship between cerebral small vessel disease (SVD) and frailty.

Methods

People aged between 60 and 85 years were randomly selected from the electoral roll into the Tasmanian Study of Cognition and Gait. Participants completed standardized questionnaires regarding medical history and underwent objective sensorimotor, gait, and cognitive testing. These data were used to calculate a frailty index score. Magnetic resonance imaging was performed on all participants to measure SVD. Automated quantification was used to measure white matter hyperintensities (WMH), with manual consensus for subcortical infarction (SI) and cerebral microbleeds (CMB). Multivariable linear regression was used to determine the association between SVD and frailty.

Results

The mean age of the sample (n = 388) was 72.0 years (SD 7.0), 44% (172/388) were female and the median Frailty Index was 0.20 (interquartile range 0.12, 0.27). WMH, SI, and CMB in unadjusted models were positively associated with higher frailty scores (p < .05). In final models including all brain variables, higher burden of WMH (β = 2.16; 95% confidence interval [CI] 0.75, 3.57; p = .003), but not SI (β = 2.96; 95% CI -0.44, 6.35; p = .09) or CMB (β = -0.46; 95% CI -4.88, 3.96; p = .84), was independently associated with a higher frailty score.

Conclusions

We provide cross-sectional evidence for a positive association between larger burden of WMH and frailty. Longitudinal design is required to determine the temporality of this relationship.

Cognitive functions and white matter lesions on magnetic resonance images in a sample of normal Iranian population with cardiovascular risk factors

PURPOSE

Due to a suggestive three-way relationship between brain structural disorders, microvascular lesions, and cognitive impairments, we aimed to examine the association of the volume and number of white matter hyperintensity lesions and lacunar infarcts with cognitive impairment among patients with cardiovascular risk factors in a sample of the Iranian population.

MATERIALS AND METHODS

This study was conducted on a total number of 156 normal subjects aged 30-74 years with cardiovascular risk factors. We used the Framingham general cardiovascular risk factors prediction model to calculate the likelihood of each risk factor. The total number of lacunar infarcts and the volume of white matter hyperintensity lesion were calculated in brain magnetic resonance imaging. Cognition status was assessed using the Montreal Cognitive Assessment questionnaire.

RESULTS

An adverse association was revealed between Montreal Cognitive Assessment score and different cardiovascular risk profiles including the Framingham body mass index score ( p < 0.001) and the Framingham lipid score ( p < 0.001). The total volume of white matter hyperintensity was negatively associated with total Montreal Cognitive Assessment cognition score ( p < 0.001). Our study also showed an adverse association between total number of lacunar infarcts and total Montreal Cognitive Assessment cognition score ( p = 0.038) and with some cognition components including memory ( p = 0.013), attention ( p = 0.037), abstraction ( p = 0.046), and orientation ( p = 0.002).

CONCLUSION

Periventricular lesions are associated with impaired memory, language, and visuoconstruction while subcortical lesions are associated with impairment in naming, attention, language, and abstraction functions in normal subjects with cardiovascular risk factors but without cardiovascular or cerebrovascular disorders.

Relation of white matter hyperintensities and motor deficits in chronic stroke

BACKGROUND

Infarct size and location account for only a relatively small portion of post-stroke motor impairment, suggesting that other less obvious factors may be involved.

OBJECTIVE

Examine the relationship between white matter hyperintensity (WMH) load among other factors and upper extremity motor deficit in patients with mild to moderate chronic stroke.

METHODS

The magnetic resonance images of 28 patients were studied. WMH load was assessed as total WMH volume and WMH overlap with the corticospinal tract in the centrum semiovale. Hemiparetic arm function was measured using the Motor Activity Log (MAL) and Wolf Motor Function Test (WMFT).

RESULTS

Hierarchical multiple regression models found WMH volume predicted motor deficits in both real-world arm use (MAL;ΔR2 = 0.12, F(1, 22) = 4.73, p = 0.04) and in arm motor capacity as measured by a laboratory motor function test (WMFT;ΔR2 = 0.18, F(1, 22) = 6.32, p = 0.02) over and above age and lesion characteristics. However, these models accounted for less than half of the variance in post-stroke motor deficits.

CONCLUSION

The results suggest that WMH may be an important factor to consider in stroke-related upper extremity motor impairment. Nonetheless, the basis of the largest part of the post-stroke motor deficit remains unaccounted for by structural CNS factors. This component may be behavioral or learned, involving learned nonuse.

Cerebral white matter disease and functional decline in older adults from the Northern Manhattan Study: A longitudinal cohort study

BACKGROUND

Cerebral white matter hyperintensities (WMHs) on MRI are common and associated with vascular and functional outcomes. However, the relationship between WMHs and longitudinal trajectories of functional status is not well characterized. We hypothesized that whole brain WMHs are associated with functional decline independently of intervening clinical vascular events and other vascular risk factors.

METHODS AND FINDINGS

In the Northern Manhattan Study (NOMAS), a population-based racially/ethnically diverse prospective cohort study, 1,290 stroke-free individuals underwent brain MRI and were followed afterwards for a mean 7.3 years with annual functional assessments using the Barthel index (BI) (range 0-100) and vascular event surveillance. Whole brain white matter hyperintensity volume (WMHV) (as percentage of total cranial volume [TCV]) was standardized and treated continuously. Generalized estimating equation (GEE) models tested associations between whole brain WMHV and baseline BI and change in BI, adjusting for sociodemographic, vascular, and cognitive risk factors, as well as stroke and myocardial infarction (MI) occurring during follow-up. Mean age was 70.6 (standard deviation [SD] 9.0) years, 40% of participants were male, 66% Hispanic; mean whole brain WMHV was 0.68% (SD 0.84). In fully adjusted models, annual functional change was -1.04 BI points (-1.20, -0.88), with -0.74 additional points annually per SD whole brain WMHV increase from the mean (-0.99, -0.49). Whole brain WMHV was not associated with baseline BI, and results were similar for mobility and non-mobility BI domains and among those with baseline BI 95-100. A limitation of the study is the possibility of a healthy survivor bias, which would likely have underestimated the associations we found.

CONCLUSIONS

In this large population-based study, greater whole brain WMHV was associated with steeper annual decline in functional status over the long term, independently of risk factors, vascular events, and baseline functional status. Subclinical brain ischemic changes may be an independent marker of long-term functional decline.

Functional Trajectories, Cognition, and Subclinical Cerebrovascular Disease

BACKGROUND AND PURPOSE

Cognition and education influence functional trajectories, but whether associations differ with subclinical brain infarcts (SBI) or white matter hyperintensity volume (WMHV) is unknown. We hypothesized that SBI and WMHV moderated relationships between cognitive performance and education and functional trajectories.

METHODS

A total of 1290 stroke-free individuals underwent brain magnetic resonance imaging and were followed for 7.3 years (mean) with annual functional assessments with the Barthel index (range, 0-100). Magnetic resonance imaging measurements included pathology-informed SBI (PI-SBI) and WMHV (% total cranial volume). Generalized estimating equation models tested associations between magnetic resonance imaging variables and baseline Barthel index and change in Barthel index, adjusting for demographic, vascular, cognitive, and social risk factors, and stroke and myocardial infarction during follow-up. We tested interactions among education level, baseline cognitive performance (Mini-Mental State score), and functional trajectories and ran models stratified by levels of magnetic resonance imaging variables.

RESULTS

Mean age was 70.6 (SD, 9.0) years; 19% had PI-SBI, and mean WMHV was 0.68%. Education did not modify associations between cognition and functional trajectories. PI-SBI modified associations between cognition and functional trajectories (P=0.04) with a significant protective effect of better cognition on functional decline seen only in those without PI-SBI. There was no significant interaction for WMHV (P=0.8). PI-SBI, and greater WMHV, were associated with 2- to 3-fold steeper functional decline, holding cognition constant.

CONCLUSIONS

PI-SBI moderated the association between cognition and functional trajectories, with 3-fold greater decline among those with PI-SBI (compared with no PI-SBI) and normal baseline cognition. This highlights the strong and independent association between subclinical markers and patient-centered trajectories over time.

Dementia

Dementia is a syndrome seen most commonly in older people and characterized by a decline in cognitive performance which impacts on the person's ability to function. There are approximately 47 million people worldwide with dementia and there are 10 million new cases every year. It is a major cause of disability and dependence and impacts on the physical, psychologic, and social well-being of families and carers. Alzheimer's disease is the most common form of dementia. Gait and balance impairments are common in people with dementia and contribute to the significantly elevated risk of falls. Older people with dementia are at increased risk of injury, institutionalization, hospitalization, morbidity, and death after a fall. There is preliminary evidence, predominantly from relatively small studies, that falls and disability can be prevented in this population. However, more good-quality research is needed, both to provide some certainty around the existing evidence base as well as to explore alternate approaches to prevention, including combined cognitive-motor training and cognitive pharmacotherapy.

Update on Vascular Cognitive Impairment Associated with Subcortical Small-Vessel Disease

Subcortical small-vessel disease (SSVD) is a disorder well characterized from the clinical, imaging, and neuropathological viewpoints. SSVD is considered the most prevalent ischemic brain disorder, increasing in frequency with age. Vascular risk factors include hypertension, diabetes, hyperlipidemia, elevated homocysteine, and obstructive sleep apnea. Ischemic white matter lesions are the hallmark of SSVD; other pathological lesions include arteriolosclerosis, dilatation of perivascular spaces, venous collagenosis, cerebral amyloid angiopathy, microbleeds, microinfarcts, lacunes, and large infarcts. The pathogenesis of SSVD is incompletely understood but includes endothelial changes and blood-brain barrier alterations involving metalloproteinases, vascular endothelial growth factors, angiotensin II, mindin/spondin, and the mammalian target of rapamycin pathway. Metabolic and genetic conditions may also play a role but hitherto there are few conclusive studies. Clinical diagnosis of SSVD includes early executive dysfunction manifested by impaired capacity to use complex information, to formulate strategies, and to exercise self-control. In comparison with Alzheimer's disease (AD), patients with SSVD show less pronounced episodic memory deficits. Brain imaging has advanced substantially the diagnostic tools for SSVD. With the exception of cortical microinfarcts, all other lesions are well visualized with MRI. Diagnostic biomarkers that separate AD from SSVD include reduction of cerebrospinal fluid amyloid-β (Aβ)42 and of the ratio Aβ42/Aβ40 often with increased total tau levels. However, better markers of small-vessel function of intracerebral blood vessels are needed. The treatment of SSVD remains unsatisfactory other than control of vascular risk factors. There is an urgent need of finding targets to slow down and potentially halt the progression of this prevalent, but often unrecognized, disorder.

Changes in Regional Brain Grey-Matter Volume Following Successful Completion of a Sensori-Motor Intervention Targeted at Healthy and Fall-Prone Older Adults

Previous studies have suggested that discrete cross-sensory events could be incorrectly combined in the brain of older adults with a history of falls, possibly undermining motor and balance control. Based on previous findings that multisensory integration is modifiable with practice, even in an ageing population, we designed a serious game, named CityQuest, to train typical, everyday multisensory processes including sensori-motor control, spatial navigation, obstacle avoidance and balance control. Played over several sessions, this game was shown to improve these functions in older adults with and without a history of falls, depending on the specific condition of the game on which they were trained. Here, using voxel-based morphometry analysis of anatomical magnetic resonance imaging (MRI) data, we investigated structural changes in the brain of a smaller group of older adults from those who successfully completed this five-week intervention. A grey-matter (GM) volume increase in the precentral gyrus, and GM volume reduction in the inferior temporal and orbitofrontal gyri, was found for all participants. Changes in GM volume within regions of the cerebellum were differentially associated with fall-prone and healthy older adults. Furthermore, a greater GM volume increase in the precentral gyrus was observed in participants who performed the full CityQuest intervention relative to those required to avoid obstacles only. Our results support previous evidence that multisensory training can affect structural changes in the older brain and have implications for programmes designed for the successful rehabilitation of perceptual and cognitive functions.

The relation between total cerebral small vessel disease burden and gait impairment in patients with minor stroke

Background and aims Individual MRI markers of cerebral small vessel disease are associated with gait impairment. The impact of total cerebral small vessel disease-related brain damage, expressed by a cerebral small vessel disease MRI burden score, on mobility after stroke, has not been considered, although this score gives a better representation of the overall effect of cerebral small vessel disease on the brain. We determined if the total cerebral small vessel disease burden is associated with gait impairment three years after minor stroke. Methods In total, 200 patients with minor lacunar or non-lacunar stroke (NIHSS ≤ 7) underwent a brain MRI at presentation. Presence of lacunes, white matter hyperintensities, cerebral microbleeds, and perivascular spaces were summed in a total cerebral small vessel disease MRI burden score (range 0-4). Gait disturbances, measured by timed-up-and-go test and self-reported stroke impact scale mobility domain were assessed three years after stroke. We tested associations adjusted for key variables by linear regression analysis. Results Total cerebral small vessel disease burden was not associated with gait impairment after minor stroke in all patients, nor in lacunar stroke patients ( n = 87). In non-lacunar stroke patients ( n = 113), total cerebral small vessel disease burden was associated with lower stroke impact scale mobility domain scores, independent of age, vascular risk factors, and stroke severity (unstandardized B -4.61; 95% CI -8.42; -0.79, p < 0.05). Conclusion Patients with non-lacunar stroke and a higher total cerebral small vessel disease burden have more subjective mobility impairment three years after stroke. The total cerebral small vessel disease MRI burden score is a possible marker to identify patients at risk for subjective gait impairment. These findings should be confirmed in larger studies.

White Matter Hyperintensity in Elderly Patients with Diabetes Mellitus Is Associated with Cognitive Impairment, Functional Disability, and a High Glycoalbumin/Glycohemoglobin Ratio

Aims: Although evidence has accumulated that white matter hyperintensity (WMH) is associated with the deterioration of cognitive function and impairment of activities of daily living (ADL), the clinical relevance of WMH in elderly patients with diabetes mellitus (DM) is not still clear. The aim of this study was to examine whether WMH volume is associated with ADL and cognitive function and whether glucose control and glucose variability can affect WMH volume in these patients.

Methods: This cross-sectional study investigated the associations of WMH with cognitive function and instrumental ADL (IADL), as well as metabolic and vascular risk factors in a total of 178 elderly patients with diabetes. The study assessed WMH volumes and the functional status of cognition and IADL. WMH volumes were evaluated by obtaining axial T2-weighted and fluid-attenuated inversion recovery sequence images on brain magnetic resonance imaging and assessing the images using Software for Neuro-Image Processing in Experimental Research.

Results: We found a significant association between WMH volumes and Mini-Mental State Examination (MMSE) scores (p = 0.039) and between WMH and IADL status (p = 0.006). Furthermore, we found significant relations of large WMH volumes with a high glycoalbumin/glycohemoglobin ratio (GA/HbA1c) (p < 0.001). Large WMH volumes were also found to be associated with a low body mass index (p = 0.014) and a low diastolic blood pressure (p = 0.024), but not with HbA1c. Multiple regression analysis showed that high GA/HbA1c, which reflects high glucose variability, was a significant determining factor for large WMH volumes. We also found that GA/HbA1c was negatively associated with both MMSE (p = 0.036) and IADL (p < 0.001).

Conclusion: GA/HbA1c, which is a marker of glucose variability, was independently associated with WMH volumes, which could lead to the decline of cognition and IADL in elderly patients with DM.

The Associations among Insulin Resistance, Hyperglycemia, Physical Performance, Diabetes Mellitus, and Cognitive Function in Relatively Healthy Older Adults with Subtle Cognitive Dysfunction

Insulin resistance (IR), diabetes mellitus (DM), sarcopenia, and cognitive dysfunction are thought to be mutually associated. We conducted a comprehensive assessment of the relationships among IR, gait speed, hyperglycemia, and DM by cross-sectionally analyzing the baseline data of an interventional study for cognitive preservation with physical exercise (the TOyota Preventional Intervention for Cognitive decline and Sarcopenia [TOPICS]). The participants (n = 444) were relatively healthy older individuals who had mild cognitive impairment without dementia, and 61 of the participants had DM. Slow gait speed and hyperglycemia were associated with cognitive dysfunction, mainly in the executive function domain, whereas IR was associated with memory impairment. The participants with DM had lower general cognition and executive function. Executive dysfunction in the DM participants seemed to be partly explained by hyperglycemia and/or slow gait speed. Our findings confirmed that IR, DM, sarcopenia, and cognitive dysfunction are mutually associated in complex ways. Understanding the mechanisms underlying these associations will lead to effective strategies to prevent and treat cognitive dysfunction in older individuals.

Valdés Hernández M, Royle NA, Corley J, Muñoz Maniega S, Pattie A, Dickie DA, Staals J, Gow AJ, Starr JM, Deary IJ, Enzinger C, Fazekas F, Wardlaw J. Impact of small vessel disease in the brain on gait and balance

Gait and balance impairment is highly prevalent in older people. We aimed to assess whether and how single markers of small vessel disease (SVD) or a combination thereof explain gait and balance function in the elderly. We analysed 678 community-dwelling healthy subjects from the Lothian Birth Cohort 1936 at the age of 71-74 years who had undergone comprehensive risk factor assessment, gait and balance assessment as well as brain MRI. We investigated the impact of individual SVD markers (white matter hyperintensity - WMH, microbleeds, lacunes, enlarged perivascular spaces, brain atrophy) as seen on structural brain MRI and of a global SVD score on the patients' performance. A regression model revealed that age, sex, and hypertension significantly explained gait speed. Among SVD markers white matter hyperintensity (WMH) score or volume were additional significant and independent predictors of gait speed in the regression model. A similar association was seen with the global SVD score. Our study confirms a negative impact of SVD-related morphologic brain changes on gait speed in addition to age, sex and hypertension independent from brain atrophy. The presence of WMH seems to be the major driving force for SVD on gait impairment in healthy elderly subjects.

Effect of galantamine on attention in patients with Alzheimer's disease combined with cerebrovascular disease

AIM

Patients with Alzheimer's disease (AD) and cerebrovascular disease (CVD) show greater attentional deficits compared with AD patients without CVD. The aim of the present study was to investigate the effect of galantamine on attention in AD patients with CVD.

METHODS

In this open trial, 1512 patients with AD and CVD were recruited from 71 nationwide hospitals. The patients were given galantamine for 16 weeks. The primary outcome measure was the score on the Attention Questionnaire Scale (AQS), which measures the patients' attention in their daily lives. The secondary outcome measures were the scores on the Korean Mini-Mental State Examination, the Clinical Dementia Rating scale and the Global Deterioration Scale. Efficacy measures were calculated both at baseline and at the end of the treatment (week 16).

RESULTS

The responders rate on the AQS (change of the AQS from baseline >0) was 60.6% in AD patients with CVD. At the end of the treatment, both the AQS (15.0 ± 5.7 vs 16.3 ± 5.8, P < 0.001) and the Korean Mini-Mental State Examination scores (17.8 ± 4.8 vs 18.1 ± 5.1, P < 0.001) showed a significant improvement relative to the baseline performance. The Clinical Dementia Rating (1.25 ± 0.59 vs 1.22 ± 0.63 P = 0.025) and Global Deterioration Scale (3.82 ± 0.94 vs 3.76 ± 0.96, P = 0.002) scores also showed a significant decrease at the end of the treatment.

CONCLUSIONS

Galantamine is effective in improving attention in the daily lives of AD patients with CVD. Geriatr Gerontol Int 2017; 17: 1661-1668.

Lacunar Infarcts Rather than White Matter Hyperintensity as a Predictor of Future Higher Level Functional Decline: The Ohasama Study

OBJECTIVE

We aimed to determine the associations between silent cerebrovascular lesions, characterized by lacunar infarcts and white matter hyperintensity, and future decline in higher level functional capacity in older community-dwelling adults.

MATERIALS AND METHODS

For this observational study, we selected individuals from the general population of Ohasama, a rural Japanese community. Three hundred thirty-one participants who were free of functional decline at baseline and who were at least 60 years old underwent brain magnetic resonance imaging and answered a questionnaire on higher level functional capacity derived from the Tokyo Metropolitan Institute of Gerontology Index of Competence. Weassessed the relationship between silent cerebrovascular lesions with a decline in higher level functional capacity at 7 years using multiple logistic regression analysis adjusted for possible confounding factors.

RESULTS

During the follow-up, 22.1% reported declines in higher level functional capacity. After adjustment for putative confounding factors, the presence of silent cerebrovascular lesions (odds ratio [95% confidence interval], 2.10 [1.05-4.21]) and both lacunar infarcts (2.04 [1.05-3.95]) and white matter hyperintensity (2.02 [1.02-3.95]) was significantly associated with the risk of functional decline at 7-year follow-up. In subscale analysis, specifically lacunar infarcts were strongly associated with the future risk of decline in intellectual activity (3.16 [1.27-7.84]).

CONCLUSION

Silent cerebrovascular lesions are associated with future risk of decline in higher level functional capacity. Appropriate management of health risk factors to prevent silent cerebrovascular lesions may prevent higher level functional decline in the elderly population.

Impact of cerebral white matter changes on functionality in older adults: An overview of the LADIS Study results and future directions

The evidence on the clinical significance of cerebral white matter changes (WMC) has mounted over the past few decades. WMC are recognized as one of the neuroimaging features of cerebral small vessel disease, and are associated with various disturbances and a poor prognosis. The Leukoaraiosis and Disability (LADIS) Study has contributed substantially to this body of knowledge. LADIS is a European multicenter collaboration aimed at assessing the role of WMC as an independent predictor of the transition to disability in initially non-disabled patients aged 65-84 years. Besides the demonstration that severe WMC cause a more than double risk of transition from an autonomous to a dependent status after 3 years of follow-up, the LADIS Study has also provided evidence on the role of WMC in relation to the decline of cognitive and motor performances, depressive symptoms associated with aging and cerebrovascular diseases, the presence of urinary disturbances, and various neurological abnormalities. The possible role of other lesions (lacunar infarcts, cerebral atrophy, corpus callosum morphology) and microstructural abnormalities (diffusion-weighted imaging changes in normal appearing brain tissue and in WMC) has also been investigated. In the present article, we review the main results of the LADIS Study and offer some considerations for future developments in the field, paying attention to the potential use of WMC progression as a surrogate marker in intervention trials in cerebral small vessel diseases. We also discuss some therapeutic perspectives regarding the beneficial impact of physical activity on the risk of vascular cognitive impairment in patients with WMC.

Diabetes mellitus and white matter hyperintensity

White matter hyperintensity (WMH) is a brain lesion detected as a high-intensity area in magnetic resonance imaging T2 and fluid-attenuated inversion recovery images, and it has been suggested that WMH reflects damage to small vessels in periventricular and subcortical areas. Although WMH has been linked to the incidence of stroke, more recently it has been clarified that WMH is also associated with progression of cognitive decline and functional disability, which are components of so-called geriatric syndrome. In addition to hypertension, which is the classical risk factor for WMH, evidence has been accumulating to suggest that diabetes mellitus could also be associated with WMH progression, and some studies have shown that WMH severity is correlated with cognitive decline in patients with diabetes. The factors that accelerate WMH formation in elderly patients with diabetes remain poorly defined. It is considered that insulin resistance is an exacerbating factor, but the effects of hypertension, dyslipidemia or other vascular risk factors have yet be clarified, and further studies are required.

BIANCA (Brain Intensity AbNormality Classification Algorithm): A new tool for automated segmentation of white matter hyperintensities

Reliable quantification of white matter hyperintensities of presumed vascular origin (WMHs) is increasingly needed, given the presence of these MRI findings in patients with several neurological and vascular disorders, as well as in elderly healthy subjects. We present BIANCA (Brain Intensity AbNormality Classification Algorithm), a fully automated, supervised method for WMH detection, based on the k-nearest neighbour (k-NN) algorithm. Relative to previous k-NN based segmentation methods, BIANCA offers different options for weighting the spatial information, local spatial intensity averaging, and different options for the choice of the number and location of the training points. BIANCA is multimodal and highly flexible so that the user can adapt the tool to their protocol and specific needs. We optimised and validated BIANCA on two datasets with different MRI protocols and patient populations (a "predominantly neurodegenerative" and a "predominantly vascular" cohort). BIANCA was first optimised on a subset of images for each dataset in terms of overlap and volumetric agreement with a manually segmented WMH mask. The correlation between the volumes extracted with BIANCA (using the optimised set of options), the volumes extracted from the manual masks and visual ratings showed that BIANCA is a valid alternative to manual segmentation. The optimised set of options was then applied to the whole cohorts and the resulting WMH volume estimates showed good correlations with visual ratings and with age. Finally, we performed a reproducibility test, to evaluate the robustness of BIANCA, and compared BIANCA performance against existing methods. Our findings suggest that BIANCA, which will be freely available as part of the FSL package, is a reliable method for automated WMH segmentation in large cross-sectional cohort studies.

Determinants of cerebral white matter changes in patients with stroke

BACKGROUND/AIM

Cerebral white matter changes (WMC) are commonly observed in magnetic resonance imaging (MRI) scans of elderly people. Information about the prevalence of WMC is limited, and little is known about site-specific risk factors for the subcortical and periventricular regions in patients with ischaemic stroke. The study aims to analyse the prevalence and severity of WMC and investigate the risk factors of periventricular WMC (PVWMC) and deep WMC (DWMC) separately in patients with ischaemic stroke.

METHODS

The data were collected between January and December 2013 from a medical centre in southern Taiwan. Every patient underwent a cerebral MRI scan, and WMC was separately rated as PVWMC and DWMC by using the modified Fazekas scale.

RESULTS

In total, 527 patients who had experienced ischaemic stroke were included. The mean age of the patients was 67.0 ± 12.5 years (range: 31-94) and 62% of them were men. The mean age was significantly different among the four grades of severity in both the PVWMC (P < 0.001) and DWMC (P < 0.001) groups after adjustments for sex and vascular risk factors. Hypertension was independently correlated with severity of DWMC (P = 0.032) but not with PVWMC (P = 0.222). In multiple logistic regressions model, hypertension was a significant independent indicator of DWMC (odds ratio = 4.30; 95% confidence interval = 1.70-10.89).

CONCLUSION

Our results suggest a region-specific pathogenesis of cerebral white matter in Asian patients with ischaemic stroke that may differ from those in the general population.

Consensus statement for diagnosis of subcortical small vessel disease

Vascular cognitive impairment (VCI) is the diagnostic term used to describe a heterogeneous group of sporadic and hereditary diseases of the large and small blood vessels. Subcortical small vessel disease (SVD) leads to lacunar infarcts and progressive damage to the white matter. Patients with progressive damage to the white matter, referred to as Binswanger's disease (BD), constitute a spectrum from pure vascular disease to a mixture with neurodegenerative changes. Binswanger's disease patients are a relatively homogeneous subgroup with hypoxic hypoperfusion, lacunar infarcts, and inflammation that act synergistically to disrupt the blood-brain barrier (BBB) and break down myelin. Identification of this subgroup can be facilitated by multimodal disease markers obtained from clinical, cerebrospinal fluid, neuropsychological, and imaging studies. This consensus statement identifies a potential set of biomarkers based on underlying pathologic changes that could facilitate diagnosis and aid patient selection for future collaborative treatment trials.

Cerebral small vessel disease and incident parkinsonism: The RUN DMC study

OBJECTIVE

To investigate the relation between baseline cerebral small vessel disease (SVD) and the risk of incident parkinsonism using different MRI and diffusion tensor imaging (DTI) measures.

METHODS

In the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC) study, a prospective cohort study, 503 elderly participants with SVD and without parkinsonism were included in 2006. During follow-up (2011-2012), parkinsonism was diagnosed according to UK Brain Bank criteria. Cox regression analysis was used to investigate the association between baseline imaging measures and incident all-cause parkinsonism and vascular parkinsonism (VP). Tract-based spatial statistics analysis was used to identify differences in baseline DTI measures of white matter (WM) tracts between participants with VP and without parkinsonism.

RESULTS

Follow-up was available from 501 participants (mean age 65.6 years; mean follow-up duration 5.2 years). Parkinsonism developed in 20 participants; 15 were diagnosed with VP. The 5-year risk of (any) parkinsonism was increased for those with a high white matter hyperintensity (WMH) volume (hazard ratio [HR] 1.8 per SD increase, 95% confidence interval [CI] 1.3-2.4) and a high number of lacunes (HR 1.4 per number increase, 95% CI 1.1-1.8) at baseline. For VP, this risk was also increased by the presence of microbleeds (HR 5.7, 95% CI 1.9-16.8) and a low gray matter volume (HR 0.4 per SD increase, 95% CI 0.2-0.8). Lower fractional anisotropy values in bifrontal WM tracts involved in movement control were observed in participants with VP compared to participants without parkinsonism.

CONCLUSIONS

SVD at baseline, especially a high WMH volume and a high number of lacunes, is associated with incident parkinsonism. Our findings favor a role of SVD in the etiology of parkinsonism.

The presence of cerebral and/or systemic endothelial dysfunction in patients with leukoaraiosis--a case control pilot study

BACKGROUND

In spite of high prevalence and clinical relevance of leukoaraiosis (LA), its pathophysiology is still incompletely understood. Theories of ischaemic genesis and a leaky blood-brain barrier are contradictory yet could share a common denominator-endothelial dysfunction (cerebral, systemic or both), which has not been studied thoroughly in LA.

METHODS

Thirty patients with LA (58 years (SD 7)) and 30 gender- and age-matched controls without LA (55 years (SD 6)) were recruited. The vascular risk factors (VRF) were identical in both groups. Cerebral endothelial function was determined by cerebrovascular reactivity to L-arginine (CVR). Systemic endothelial function was determined by flow-mediated dilatation (FMD) of the brachial artery after hyperaemia. All participants underwent a brain MRI to search for radiological signs of LA that was classified according to the Fazekas score. Linear regression was used to explore the correlation between CVR and FMD in patients with LA. A 95 % confidence interval was used. For any statistical test used in the study, p ≤ 0.050 was regarded as statistically significant.

RESULTS

We found a marked and significant decrease in both CVR (9.6 % (SD 3.2) vs. 15.8 % (SD 6.1), p < 0.001) and FMD (4.8 % (SD 3.1) vs. 7.4 % (SD 3.8), p = 0.004) in LA patients compared to controls. Both CVR (7.4 % (SD 3.1) vs. 12.2 % (SD 2.6), p = 0.001) and FMD (3.0 % (SD 2.2) vs. 6.4 % (SD 3.1), p = 0.011) were significantly decreased in LA subgroup Fazekas 3 compared to subgroup Fazekas 1. CVR and FMD significantly positively correlated (b = 0.192, 95 % CI = 0.031-0.354, p = 0.02).

CONCLUSIONS

The results of our pilot study suggest that patients with LA have a significant impairment of both cerebral and systemic endothelial function that is larger than could be expected based on present VRF. Endothelial dysfunction increases in parallel with LA severity and correlates between cerebral and systemic arterial territory. Overall, our results suggest a so far unknown "intrinsic" generalised endothelial dysfunction in patients with LA that could be involved in LA pathophysiology. This interesting issue needs to be confirmed in larger samples since it could help better understand the mechanisms underlying LA.