Subcortical Ischemic Vascular Dementia Patients Research Articles

Immunological Profile and Markers of Endothelial Dysfunction in Elderly Patients with Cognitive Impairments.

The process of aging is accompanied by a dynamic restructuring of the immune response, a phenomenon known as immunosenescence. Further, damage to the endothelium can be both a cause and a consequence of many diseases, especially in elderly people. The purpose of this study was to carry out immunological and biochemical profiling of elderly people with acute ischemic stroke (AIS), chronic cerebral circulation insufficiency (CCCI), prediabetes or newly diagnosed type II diabetes mellitus (DM), and subcortical ischemic vascular dementia (SIVD). Socio-demographic, lifestyle, and cognitive data were obtained. Biochemical, hematological, and immunological analyses were carried out, and extracellular vesicles (EVs) with endothelial CD markers were assessed. The greatest number of significant deviations from conditionally healthy donors (HDs) of the same age were registered in the SIVD group, a total of 20, of which 12 were specific and six were non-specific but with maximal differences (as compared to the other three groups) from the HDs group. The non-specific deviations were for the MOCA (Montreal Cognitive Impairment Scale), the MMSE (Mini Mental State Examination) and life satisfaction self-assessment scores, a decrease of albumin levels, and ADAMTS13 (a Disintegrin and Metalloproteinase with a Thrombospondin Type 1 motif, member 13) activity, and an increase of the VWF (von Willebrand factor) level. Considering the significant changes in immunological parameters (mostly Th17-like cells) and endothelial CD markers (CD144 and CD34), vascular repair was impaired to the greatest extent in the DM group. The AIS patients showed 12 significant deviations from the HD controls, including three specific to this group. These were high NEFAs (non-esterified fatty acids) and CD31 and CD147 markers of EVs. The lowest number of deviations were registered in the CCCI group, nine in total. There were significant changes from the HD controls with no specifics to this group, and just one non-specific with a maximal difference from the control parameters, which was α1-AGP (alpha 1 acid glycoprotein, orosomucoid). Besides the DM patients, impairments of vascular repair were also registered in the CCCI and AIS patients, with a complete absence of such in patients with dementia (SIVD group). On the other hand, microvascular damage seemed to be maximal in the latter group, considering the biochemical indicators VWF and ADAMTS13. In the DM patients, a maximum immune response was registered, mainly with Th17-like cells. In the CCCI group, the reaction was not as pronounced compared to other groups of patients, which may indicate the initial stages and/or compensatory nature of organic changes (remodeling). At the same time, immunological and biochemical deviations in SIVD patients indicated a persistent remodeling in microvessels, chronic inflammation, and a significant decrease in the anabolic function of the liver and other tissues. The data obtained support two interrelated assumptions. Taking into account the primary biochemical factors that trigger the pathological processes associated with vascular pathology and related diseases, the first assumption is that purine degradation in skeletal muscle may be a major factor in the production of uric acid, followed by its production by non-muscle cells, the main of which are endothelial cells. Another assumption is that therapeutic factors that increase the levels of endothelial progenitor cells may have a therapeutic effect in reducing the risk of cerebrovascular disease and related neurodegenerative diseases.

Neurovascular Correlates of Cobalamin, Folate, and Homocysteine in Dementia.

Cobalamin (Cbl) and folate are common supplements clinicians prescribe as an adjuvant therapy for dementia patients, on the presumption of their neurotrophic and/or homocysteine (Hcy) lowering effect. However, the treatment efficacy has been found mixed and the effects of Cbl/folate/Hcy on the human brain remain to be elucidated. To explore the neurovascular correlates of Cbl/folate/Hcy in Alzheimer's disease (AD) and subcortical ischemic vascular dementia (SIVD). Sixty-seven AD patients and 57 SIVD patients were prospectively and consecutively recruited from an outpatient clinic. Multimodal 3-Tesla magnetic resonance imaging was performed to quantitatively evaluate cerebral blood flow (CBF) and white matter integrity. The relationship between neuroimaging metrics and the serum levels of Cbl/folate/Hcy was examined by using the Kruskal-Wallis test, partial correlation analysis, and moderation analysis, at a significance level of 0.05. As a whole, CBF mainly associated with Cbl/folate while white matter hyperintensities exclusively associated with Hcy. As compared with AD, SIVD exhibited more noticeable CBF correlates (spatially widespread with Cbl and focal with folate). In SIVD, a bilateral Cbl-moderated CBF coupling was found between medial prefrontal cortex and ipsilateral basal ganglia, while in the fronto-subcortical white matter tracts, elevated Hcy was associated with imaging metrics indicative of increased injury in both axon and myelin sheath. We identified the neurovascular correlates of previously reported neurotrophic effect of Cbl/folate and neurotoxic effect of Hcy in dementia. The correlates exhibited distinct patterns in AD and SIVD. The findings may help improving the formulation of supplemental Cbl/folate treatment for dementia.

Effect of White Matter Hyperintensities on Daily Function via Depressive Symptoms: A Longitudinal Study in Patients With Dementia Including Alzheimer's Disease and Subcortical Ischemic Vascular Dementia.

Objective This study aimed to investigate the mediation effect of depressive symptoms on the relationship between white matter hyperintensities and the basic activities of daily living (BADL) using an integrated approach to overcome the limitations of previous studies and examine the relationship among the three variables simultaneously. Methods We performed structural equation modeling using cross-sectional data from 497 Alzheimer’s disease (AD), AD with small vessel disease, and subcortical ischemic vascular dementia patients enrolled in the Clinical Research for Dementia of South Korea registry who were diagnosed with mild-to-moderate dementia. Periventricular white matter hyperintensities (PWMHs) and deep white matter hyperintensities (DWMHs) were visualized separately at baseline using magnetic resonance imaging. Depressive symptoms were assessed using the Korean Form of the Geriatric Depression Scale at the follow-up assessment conducted after 1 year. BADL were assessed using the Barthel Index at the follow-up assessment conducted after 2 years. Results The direct and indirect effects of DWMHs on the BADL as mediated via depression were significant. However, neither the direct effect of PWMHs on the BADL nor the indirect effect of PWMHs on the BADL via depression were significant. Conclusion This study presented a mediation model that included a longitudinal developmental pathway from DWMHs to deterioration in the BADL mediated via depressive symptoms. Moreover, the mediation model of depressive symptoms could not be applied to the longitudinal developmental pathway from DWMHs to the deterioration in BADL.

Transcriptome Profiling of Mouse Corpus Callosum After Cerebral Hypoperfusion.

White matter damage caused by cerebral hypoperfusion is a major hallmark of subcortical ischemic vascular dementia (SIVD), which is the most common subtype of vascular cognitive impairment and dementia (VCID) syndrome. In an aging society, the number of SIVD patients is expected to increase; however, effective therapies have yet to be developed. To understand the pathological mechanisms, we analyzed the profiles of the cells of the corpus callosum after cerebral hypoperfusion in a preclinical SIVD model. We prepared cerebral hypoperfused mice by subjecting 2-month old male C57BL/6J mice to bilateral carotid artery stenosis (BCAS) operation. BCAS-hypoperfusion mice exhibited cognitive deficits at 4 weeks after cerebral hypoperfusion, assessed by novel object recognition test. RNA samples from the corpus callosum region of sham- or BCAS-operated mice were then processed using RNA sequencing. A gene set enrichment analysis using differentially expressed genes between sham and BCAS-operated mice showed activation of oligodendrogenesis pathways along with angiogenic responses. This database of transcriptomic profiles of BCAS-hypoperfusion mice will be useful for future studies to find a therapeutic target for SIVD.

White Matter Structural Network Analysis to Differentiate Alzheimer's Disease and Subcortical Ischemic Vascular Dementia.

To explore the evaluation of white matter structural network analysis in the differentiation of Alzheimer’s disease (AD) and subcortical ischemic vascular dementia (SIVD), 67 participants [31 AD patients, 19 SIVD patients, and 19 normal control (NC)] were enrolled in this study. Each participant underwent 3.0T MRI scanning. Diffusion tensor imaging (DTI) data were analyzed by graph theory (GRETNA toolbox). Statistical analyses of global parameters [gamma, sigma, lambda, global shortest path length (Lp), global efficiency (Eg), and local efficiency (Eloc)] and nodal parameters [betweenness centrality (BC)] were obtained. Network-based statistical analysis (NBS) was employed to analyze the group differences of structural connections. The diagnosis efficiency of nodal BC in identifying different types of dementia was assessed by receiver operating characteristic (ROC) analysis. There were no significant differences of gender and years of education among the groups. There were no significant differences of sigma and gamma in AD vs. NC and SIVD vs. NC, whereas the Eg values of AD and SIVD were statistically decreased, and the lambda values were increased. The BC of the frontal cortex, left superior parietal gyrus, and left precuneus in AD patients were obviously reduced, while the BC of the prefrontal and subcortical regions were decreased in SIVD patients, compared with NC. SIVD patients had decreased structural connections in the frontal, prefrontal, and subcortical regions, while AD patients had decreased structural connections in the temporal and occipital regions and increased structural connections in the frontal and prefrontal regions. The highest area under curve (AUC) of BC was 0.946 in the right putamen for AD vs. SIVD. White matter structural network analysis may be a potential and promising method, and the topological changes of the network, especially the BC change in the right putamen, were valuable in differentiating AD and SIVD patients.

Forgetting Rate on the Recency Portion of a Word List Differentiates Mild to Moderate Alzheimer's Disease from Other Forms of Dementia.

Patients with Alzheimer's disease (AD) demonstrate a disproportionately larger forgetting rate in episodic memory tasks. Previous studies documented that, in comparison with healthy controls, the increased forgetting manifested by AD patients in word list recall tasks is confined to the recency portion of the list with normal forgetting rates on the primacy and mid-list portions. In this study we compared the primacy, mid-list, and recency ratios, obtained by dividing the immediate and delayed recall of words in position 1-4, 5-11, and 12-15 of a 15-word list, in different groups of demented patients, i.e., AD, frontal variant of frontotemporal dementia (fvFTD), Lewy body disease (LBD), subcortical ischemic vascular dementia (SIVD), and a group of normal controls (NC). The aim was to investigate whether the above reported forgetting pattern would differentiate AD performance from that of other dementia groups. Results of the statistical analysis showed that only the recency ratio differentiated AD from patients in the other dementia groups. Consistently, hierarchical logistic regression analyses demonstrated that the recency ratio discriminated between AD patients and individuals affected by other forms of dementia. In particular, the discrimination power was high in differentiating AD from fvFTD patients but was less accurate in differentiating AD from LBD and SIVD patients. We assume that the increased forgetting in AD patients is due to a deficit in memory consolidation mechanisms (specific to AD) that prevent the terminal items in a list from being transferred from a temporary short-term memory store to a stable long-term memory store.

Forgetting Rate on the Recency Portion of a Word List Differentiates Mild to Moderate Alzheimer's Disease from Other Forms of Dementi.

Patients with Alzheimer's disease (AD) demonstrate a disproportionately larger forgetting rate in episodic memory tasks. Previous studies documented that, in comparison with healthy controls, the increased forgetting manifested by AD patients in word list recall tasks is confined to the recency portion of the list with normal forgetting rates on the primacy and mid-list portions. In this study we compared the primacy, mid-list, and recency ratios, obtained by dividing the immediate and delayed recall of words in position 1-4, 5-11, and 12-15 of a 15-word list, in different groups of demented patients, i.e., AD, frontal variant of frontotemporal dementia (fvFTD), Lewy body disease (LBD), subcortical ischemic vascular dementia (SIVD), and a group of normal controls (NC). The aim was to investigate whether the above reported forgetting pattern would differentiate AD performance from that of other dementia groups. Results of the statistical analysis showed that only the recency ratio differentiated AD from patients in the other dementia groups. Consistently, hierarchical logistic regression analyses demonstrated that the recency ratio discriminated between AD patients and individuals affected by other forms of dementia. In particular, the discrimination power was high in differentiating AD from fvFTD patients but was less accurate in differentiating AD from LBD and SIVD patients. We assume that the increased forgetting in AD patients is due to a deficit in memory consolidation mechanisms (specific to AD) that prevent the terminal items in a list from being transferred from a temporary short-term memory store to a stable long-term memory store.

Regional amyloid burden and lacune in pure subcortical vascular cognitive impairment

We investigated the amyloid and vascular burden in Pittsburgh compound B (PiB)–negative subcortical vascular mild cognitive impairment (svMCI) and PiB-negative subcortical ischemic vascular dementia (SIVD) to elucidate the potential roles of amyloid deposition and small vessel disease (SVD). Thirty-eight svMCI patients and 42 SIVD patients were enrolled. The regional PiB uptake values and SVD markers were obtained and compared between groups. Additionally, correlations among amyloid burden, SVD, and cognition were made. Patients with PiB-negative SIVD showed more amyloid deposition than those with PiB-negative svMCI, particularly in the cuneus, lingual gyrus, supramarginal, and angular gyri. Despite subthreshold levels for amyloid deposition, our findings showed a marked regional difference in amyloid uptake between svMCI and SIVD, particularly in posteriorly located brain areas. However, lacune, a proxy for vascular burden, showed a broader association with cognition and had more impacts on developing dementia than amyloid burden. The topographical pattern of amyloid deposition and its impact on clinical status in pure subcortical vascular cognitive impairment were different from those in Alzheimer's disease.

73. Neurophysiological features of motor cortex excitability and plasticity in Subcortical Ischemic Vascular Dementia: A TMS mapping study

The aim of this study was to evaluate neurophysiological features of M1 excitability and plasticity in Subcortical Ischemic Vascular Dementia (SIVD), by means of TMS mapping technique. Seven SIVD and nine AD patients, along with nine control subjects were tested. The M1 excitability was studied by resting thresholds, area and volume of active cortical sites for forearm and hand’s examined muscles. For M1 plasticity, coordinates of the hot-spot and the center of gravity (CoG) were evaluated. The correlation between the degree of hyperexcitability and the amount of M1 plastic rearrangement was also calculated. Multivariate analysis of excitability measures demonstrated similarly enhanced cortical excitability in AD and SIVD patients with respect to controls. SIVD patients showed a medial and frontal shift of CoG from the hot-spot, not statistically different from that observed in AD. A significant direct correlation was seen between parameters related to cortical excitability and those related to cortical plasticity. The results suggest the existence of common compensatory mechanisms in different kind of dementing diseases supporting the idea that cortical hyperexcitability can promote cortical plasticity. This study characterizes neurophysiological features of motor cortex excitability and plasticity in SIVD, providing new insights on the correlation between cortical excitability and plasticity.

Characterizing brain iron deposition in subcortical ischemic vascular dementia using susceptibility-weighted imaging: An in vivo MR study

The aim of this study was to investigate the brain iron accumulation in subcortical ischemic vascular dementia (SIVD) and its correlation with the severity of cognitive impairment. Thirty five patients with SIVD and 35 healthy controls underwent high-resolution susceptibility-weighted imaging. The phase shift value of the bilateral hippocampus (HP), caudate nucleus (CN), globus pallidus (GP), putamen (PU), thalamus (TH), red nucleus (RN), substantia nigra (SN), anterior cingulate cortex (ACC), posterior cingulate (PCC), parietal cortex (PC) and frontal white matter (FWM) were examined and correlated with neuropsychological scores for SIVD patients. They exhibited significant increased phase shift values in the bilateral HP, CN, PU, right GP and left SN (P<0.05). Close correlations were found between the phase shift value of the left HP, right CN and neuropsychological scores. Our results suggest that brain iron deposition may be a biomarker of SIVD and play an important role in the pathophysiological mechanism.

Quantitative measurement to evaluate morphological changes of the corpus callosum in patients with subcortical ischemic vascular dementia

Subcortical ischemic vascular dementia (SIVD) is a subtype of dementia associated with abnormalities in the subcortical white matter regions. Recent imaging techniques can be used to detect such abnormalities invivo. To examine morphological changes of the corpus callosum in patients with SIVD by using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). MRI was performed to explore changes of cerebral white matter, especially corpus callosum. Brain matter diffusivity was examined with DTI by measuring the fractional anisotropy (FA). Results of 30 patients diagnosed with SIVD and 30 healthy subjects were analyzed and compared. The thicknesses of the genu, the anterior third, middle, and posterior third of the body, and the splenium of the corpus callosum were smaller in SIVD patients compared to healthy controls (0.54 ± 0.08 vs. 0.68 ± 0.09 cm, P = 0.0011; 0.27 ± 0.06 vs. 0.38 ± 0.07 cm, P = 0.002; 0.28 ± 0.05 vs. 0.38 ± 0.08 cm, P = 0.009; 0.18 ± 0.04 vs. 0.26 ± 0.06 cm, P = 0.013; 0.54 ± 0.07 vs. 0.72 ± 0.09 cm, P = 0.003, respectively). The FA values of the genu and splenium of the corpus callosum in patients with SIVD were decreased compared to healthy controls (0.664 ± 0.042 vs. 0.778 ± 0.041, P < 0.001; 0.691 ± 0.038 vs. 0.786 ± 0.039, P = 0.001, respectively). Patients with SIVD exhibit corpus callosum atrophy and morphological changes, and these characteristics may be useful for diagnosis.

Neurophysiological features of motor cortex excitability and plasticity in Subcortical Ischemic Vascular Dementia: A TMS mapping study

ObjectiveTo evaluate neurophysiological features of M1 excitability and plasticity in Subcortical Ischemic Vascular Dementia (SIVD), by means of a TMS mapping study. MethodsSeven SIVD and nine AD patients, along with nine control subjects were tested. The M1 excitability was studied by resting thresholds, area and volume of active cortical sites for forearm and hand’s examined muscles. For M1 plasticity, coordinates of the hot-spot and the center of gravity (CoG) were evaluated. The correlation between the degree of hyperexcitability and the amount of M1 plastic rearrangement was also calculated. ResultsMultivariate analysis of excitability measures demonstrated similarly enhanced cortical excitability in AD and SIVD patients with respect to controls. SIVD patients showed a medial and frontal shift of CoG from the hot-spot, not statistically different from that observed in AD. A significant direct correlation was seen between parameters related to cortical excitability and those related to cortical plasticity. ConclusionsThe results suggest the existence of common compensatory mechanisms in different kind of dementing diseases supporting the idea that cortical hyperexcitability can promote cortical plasticity. SignificanceThis study characterizes neurophysiological features of motor cortex excitability and plasticity in SIVD, providing new insights on the correlation between cortical excitability and plasticity.

Analysis of Cerebral Blood Flow with Single Photon Emission Computed Tomography in Mild Subcortical Ischemic Vascular Dementia

The mechanism of cognitive dysfunction of subcortical ischemic vascular dementia (SIVaD) is not yet fully understood. The objective of this study was to investigate and compare the distribution of regional cerebral perfusion (CP) change in the mild forms of SIVaD, a relatively homogeneous subtype of vascular dementia, using statistical parametric mapping (SPM) analysis of the technetium-99m hexamethylproplyeneamineoxime (Tc-99m HMPAO) single photon emission computed tomography (SPECT). A total of 28 patients with mild SIVaD and 33 healthy controls were prospectively recruited and underwent SPECT imaging studies between January 2012 and May 2013. SPECT was performed to measure the regional CP, and SPM was applied to the analysis of the SPECT data. The regional CP was significantly decreased in the bilateral insula, anterior and posterior cingulated gyrus, precentral gyrus, and subcallosal gyrus as well as the right inferior parietal lobule in the SIVaD patients compared to the controls (corrected p = 0.01). The pattern of CP abnormality correlated well with those previously reported in later forms of SIVaD. Reduction of CP in the brain areas mentioned was present earlier on in the natural course of SIVaD pathophysiology. Our study suggests that cognitive dysfunction of SIVaD may be related to these regional CP deficits.

N-methyl-d-aspartate glutamate receptor (NMDA-R) antibodies in mild cognitive impairment and dementias

The N-methyl-d-aspartate glutamate receptor (NMDA-R) plays a central role in learning and memory and has therefore a potential role in the pathophysiology of neuropsychiatric disorders. Recently, we detected NMDA-R autoantibodies in aged healthy volunteers without neuropsychiatric disorders.Since studies showing the involvement of NMDA-R antibodies in mild cognitive impairment and different forms of dementia are rare, we examined NMDA-R antibodies (Abs) in serum of 46 patients with Alzheimer's disease (AD), 26 patients with subcortical ischemic vascular dementia (SIVD), 18 patients with frontotemporal dementia (FTD), 11 patients with Lewy body disease (LBD) and 33 patients with mild cognitive impairment (MCI) and in 21 healthy aged, gender-matched volunteers. While IgM and/or IgA NMDA-R Abs were present in all groups, IgG was only detected in one AD sample. Seropositivity could be correlated with the presence of co-symptoms: MCI and AD patients suffering from depression and AD and SIVD patients with a psychosis were almost all NMDA-R Ab positive.We conclude that the presence of NMDA-R Abs in dementia could influence the incidence of comorbid depressive and/or psychotic states.

The pattern of brain gray matter impairments in patients with subcortical vascular dementia

Though subcortical ischemic vascular dementia (SIVD) is known to initially affect subcortical regions, numerous brain imaging studies have also documented the widespread cortical alternations. Here we collected brain structural magnetic resonance imaging data from 34 SIVD patients and 35 healthy controls. Voxel-based morphometry (VBM), cortical thickness (and surface area) analysis and deep gray matter volume measurements were performed. VBM analysis showed gray matter volume reduction in lateral and medial temporal lobes, as well as orbitofrontal cortex in SIVD patients. The surface-based analyses revealed more subtle structural differences in the perisylvian area, medial temporal lobe, anterior and posterior cingulate, as well as prefrontal areas. Furthermore, analyses of deep gray matter demonstrated significant atrophy of the hippocampus, amygdala, nucleus accumbens and other nuclei. Finally, we found that thinning in the hippocampus and anterior cingulate cortex, as well as the volume decline in thalamus, caudate nucleus and amygdala was correlated with the cognitive impairment in patients. In conclusion, our study showed the structural abnormalities of the hippocampus and its associated outflow areas, as well as cortices implicated in cholinergic circuits in SIVD. These findings may bring new insights into the dysfunction of brain gray matter in SIVD.

Magnetoencephalography assessment of evoked magnetic fields and cognitive function in subcortical ischemic vascular dementia patients

ObjectiveTo investigate the relationship between cognitive impairment and somatosensory evoked magnetic field and auditory evoked magnetic field changes in elderly male patients with subcortical ischemic vascular dementia (SIVD). MethodsMagnetoencephalography (MEG) was used to record evoked magnetic field changes from 4 SIVD patients (76–88 years), 3 patients with vascular cognitive impairment with no dementia (VCI-ND; 74–87 years), and 6 healthy volunteers (72–85 years). Latency peaks, equivalent current dipole (ECD) strength, and bilateral ECD position were recorded. The MEG data were superimposed on magnetic resonance imaging to produce magnetic source imaging. ResultsCompared to controls, SIVD patients showed increased M20 latency and ECD strength. There were no significant differences in M20 inter-hemispheric positions across diagnostic categories. At M100, SIVD patients showed delayed auditory evoked magnetic field latency compared to controls. However, ECD strength and 3-dimensional inter-hemispheric differences were similar across the groups at the M100 measurement. ConclusionsChanges in somatosensory and auditory evoked magnetic field changes correlated with cognitive impairment in SIVD patients. Magnetic field latency measures may provide an objective and sensitive index for early dementia detection and monitoring of cognitive function.

The value of diffusion tensor imaging in the differential diagnosis of subcortical ischemic vascular dementia and Alzheimer's disease in patients with only mild white matter alterations on T2-weighted images

Diffusion tensor imaging (DTI) is a form of functional magnetic resonance imaging (MRI) that allows examination of the microstructural integrity of white matter in the brain. Dementia is a neurodegenerative disease, and DTI can provide indirect insights of the microstructural characteristics of brains in individuals with different forms of dementia. To evaluate the value of DTI in the diagnosis and differential diagnosis of patients with subcortical ischemic vascular dementia (SIVD) and Alzheimer's disease (AD). The study included 40 patients (20 AD patients and 20 SIVD patients) and 20 normal controls (NC). After routine MRI and DTI, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured and compared in regions of interest (ROI). Compared to NC and AD patients, SIVD patients had lower FA values and higher ADC values in the inferior-fronto-occipital fascicles (IFOF), genu of the corpus callosum (GCC), splenium of the corpus callosum (SCC), and superior longitudinal fasciculus (SLF). Compared to controls and SIVD patients, AD patients had lower FA values in the anterior frontal lobe, temporal lobe, hippocampus, IFOF, GCC, and CF; and higher ADC values in the temporal lobe and hippocampus. DTI can be used to estimate the white matter impairment in dementia patients. There were significant regional reductions of FA values and heightened ADC values in multiple regions in SIVD patients compared to AD patients. When compared with conventional MRI, DTI may provide a more objective method for the differential diagnosis of SIVD and AD disease patients who have only mild white matter alterations on T2-weighted imaging.

The Profile of Hippocampal Metabolites Differs between Alzheimer's Disease and Subcortical Ischemic Vascular Dementia, as Measured by Proton Magnetic Resonance Spectroscopy

Alzheimer's disease (AD) and subcortical ischemic vascular dementia (SIVD) have overlapping pathologies and risk factors, but their underlying neurodegenerative mechanisms are basically different. We performed magnetic resonance spectroscopy (MRS) to study metabolite differences between the two diseases in vivo. The subjects were 31 patients with SIVD and 99 with AD. Additionally, 45 elderly subjects were recruited as controls. We measured N-acetylaspartate (NAA), glutamine and glutamate (Glx), and myoinositol (mIns) concentration quantitatively using a 1.5-T MR scanner. N-acetylaspartate and Glx concentrations decreased in the hippocampus and cingulate/precuneal cortices (PCC) in both AD and SIVD patients, and the NAA decrease in the hippocampus was more prominent in AD than in SIVD. Interestingly, the pattern of mIns concentration changes differed between the two disorders; mIns was increased in AD but not increased in SIVD. If one differentiates between AD and SIVD by the mIns concentration in the hippocampus, the area under the receiver operating characteristic curve was 0.95, suggesting a high potential for discrimination. Our results suggest that proton MRS can provide useful information to differentiate between AD and SIVD. The difference of mIns concentrations in the hippocampus and PCC seems to reflect the different neurodegenerative mechanisms of the two disorders.

The Chinese (Cantonese) Montreal Cognitive Assessment in Patients with Subcortical Ischemic Vascular Dementia

Background: Subcortical ischemic vascular dementia (SIVD) has been proposed as the most frequent subtype of vascular cognitive impairment. The aim of this study was to evaluate the psychometric properties of the Chinese (Cantonese) Montreal Cognitive Assessment (CC- MoCA) in patients with SIVD in the Guangdong Province of China. Methods: 71 SIVD patients and 60 matched controls were recruited for the CC-MoCA, Mini Mental State Examination and executive clock drawing tasks. Receiver-operating characteristic curve analyses were performed to determine optimal sensitivity and specificity of the CC-MoCA total score in differentiating mild vascular dementia (VaD) patients from moderate VaD patients and controls. Results: The mean CC-MoCA scores of the controls, and mild and moderate VaD patients were 25.2 ± 3.8, 16.4 ± 3.7, and 10.0 ± 5.1, respectively. In our study, the optimal cutoff value for the CC-MoCA to be able to differentiate patients with mild VaD from controls is 21/22, and 13/14 to differentiate mild VaD from moderate VaD. Conclusion: The CC-MoCA is a useful cognitive screening instrument in SIVD patients.

Effects of Subcortical Vascular Ischemic Dementia and Aging on Negative and Neutral Word List Learning

Background: Subcortical ischemic vascular dementia (SIVD) represents an important subgroup of vascular dementia. Besides characteristic cognitive deficits, particular emotional problems support the diagnosis. Emotional disturbances in SIVD are not well understood. Method: We studied the performance of SIVD patients, healthy young control persons and old control persons in an emotional word list learning task. Results: SIVD patients showed lower memory performance than both control groups for neutral as well as for negative words. However, we found a significant emotional memory advantage for negative words in all 3 diagnostic groups. Conclusion: SIVD patients are able to profit from emotional information in order to enhance their memory performance.