Subcortical Vascular Dementia Group Research Articles

Relationships between educational attainment, hypertension, and amyloid negative subcortical vascular dementia: The brain-battering hypothesis.

PurposeMany epidemiological studies suggest that lower education levels and vascular risk factors increase the likelihood of developing Alzheimer's disease dementia (ADD) and subcortical vascular dementia (SVaD). However, whether the brain-battering hypothesis can explain the relationship between education levels and the clinical diagnosis of dementia remains controversial. The objective of this study was to investigate whether vascular risk factors mediate the association between education level and the diagnosis of amyloid-beta positive (Aβ+) ADD and amyloid-beta negative (Aβ-) SVaD.MethodsWe analyzed 376 participants with Aβ normal cognition (Aβ- NC), 481 with Aβ+ ADD, and 102 with Aβ- SVaD. To investigate the association of education level and vascular risk factors with these diagnoses, multivariable logistic regression analysis was used, with age, sex, and APOE ε4 carrier status used as covariates. Path analysis was performed to investigate the mediation effects of hypertension on the diagnosis of Aβ- SVaD.ResultsThe Aβ- SVaD group (7.9 ± 5.1 years) had lower education levels than did the Aβ- NC (11.8 ± 4.8 years) and Aβ+ ADD (11.2 ± 4.9 years) groups. The frequencies of hypertension and diabetes mellitus were higher in the Aβ- SVaD group (78.4 and 32.4%, respectively) than in the Aβ- NC (44.4 and 20.8%) and Aβ+ ADD (41.8 and 15.8%, respectively) groups. Increased education level was associated with a lower risk of Aβ- SVaD [odds ratio (OR) 0.866, 95% confidence interval (CI), 0.824–0.911], but not Aβ+ ADD (OR 0.971, 95% CI 0.940–1.003). The frequency of hypertension was associated with a higher risk of developing Aβ- SVaD (OR 3.373, 95% CI, 1.908–5.961), but not Aβ+ ADD (OR 0.884, 95% CI, 0.653–1.196). In the path analysis, the presence of hypertension partially mediated the association between education level and the diagnosis of Aβ- SVaD.ConclusionOur findings revealed that education level might influence the development of Aβ- SVaD through the brain-battering hypothesis. Furthermore, our findings suggest that suitable strategies, such as educational attainment and prevention of hypertension, are needed for the prevention of Aβ- SVaD.

Written Spelling in Patients with Subcortical Vascular Dementia and Subcortical Vascular Mild Cognitive Impairment

Objectives: The purpose of this study is to examine the spelling processing patterns in patients with subcortical vascular dementia (SVaD) and subcortical vascular mild cognitive impairment (svMCI).Methods: The subjects consisted of 10 patients with SVaD, 15with svMCI, and 30 normal controls (NC) subjects. Prior to this study, Korean- Mini Mental Status Examination (K-MMSE), Montreal Cognitive Assessment (MoCA-K), and health screening questionnaires were conducted as pre-tests. After that, subjects were presented with 20 words grouped according to word type (regular word, irregular word, non-word), and then they were asked to dictate the words they heard. After the tests were completed, the number of correct responses and the number of error patterns were compared between groups.Results: First, by word type between groups, the svMCI and SVaD groups showed a significantly lower number of correct responses for regular and irregular words compared to the NC group. In addition, the SVaD group showed a significantly lower number of forward responses than the svMCI group in irregular words. Non-words showed significantly lower number of forward responses in the SVaD group compared to the NC and svMCI groups. Second, the comparison of the number of error types between groups showed a significant difference between the three groups in terms of grapheme substitution; and the SVaD group showed significantly more errors compared with the NC and svMCI groups in addition and omission of graphemes. Third, the SVaD group showed significantly more errors in comparison to the NC and svMCI groups for phonological implausible errors, and the svMCI and SVaD groups showed significantly more errors than the NC group for phonological plausible errors. Fourth, lexicalization errors within non-words were observed only in the SVaD group.Conclusion: For early detection of svMCI, it is necessary to pay attention to irregular word performance.

Changes in Microvascular Morphology in Subcortical Vascular Dementia: A Study of Vessel Size Magnetic Resonance Imaging.

Background: Cerebral small vessel disease is the most common cause of subcortical vascular dementia (SVaD). Unfortunately, conventional imaging techniques do not always demonstrate the microvascular pathology that is associated with small vessel disease. The purpose of this study was to evaluate the changes in the microvascular structure of SVaD and to identify how the microvascular changes in vessel size, detected with imaging, affect the gray matter.Methods: Ten SVaD patients and 12 healthy controls underwent vessel size imaging with gradient-echo and spin-echo sequences before and after contrast agent injection. Four microvessel index maps, including total blood volume fraction (BVf), mean vessel density (Q), mean vessel diameter (mVD), and vessel size index (VSI) were calculated. ROI value of each microvessel parameter was compared between SVaD patients and controls. Voxel-wise comparison of microvessel parameters was also performed to assess the regional difference. The relationship between the microvessel parameters in white matter and total gray matter volume (TGV) were assessed.Results: Both mVD and VSI were significantly different between the SVaD and controls in the ROI-based comparisons (unpaired t-test, p < 0.05). mVD and VSI were significantly increased in the SVaD group at the subcortical, periventricular white matter, basal ganglia, and thalami compared with the controls (FDR corrected, p < 0.05). VSI in the white matter areas were significantly negatively correlated with TGV (r = −0.446, p < 0.05).Conclusions: The increase of mVD and VSI in SVaD patients reflects the damage of the microvessels in the white matter, and these changes may lead to the damage of the gray matter.

The impact of education on cortical thickness in amyloid-negative subcortical vascular dementia: cognitive reserve hypothesis

BackgroundThe protective effect of education has been well established in Alzheimer’s disease, whereas its role in patients with isolated cerebrovascular diseases remains unclear. We examined the correlation of education with cortical thickness and cerebral small vessel disease markers in patients with pure subcortical vascular mild cognitive impairment (svMCI) and patients with pure subcortical vascular dementia (SVaD).MethodsWe analyzed 45 patients with svMCI and 47 patients with SVaD with negative results on Pittsburgh compound B positron emission tomographic imaging who underwent structural brain magnetic resonance imaging. The main outcome was cortical thickness measured using surface-based morphometric analysis. We also assessed the volumes of white matter hyperintensities (WMH) and numbers of lacunes as other outcomes. To investigate the correlation of education with cortical thickness, WMH volume, and number of lacunes, multiple linear regression analyses were performed after controlling for covariates, including Mini Mental State Examination, in the svMCI and SVaD groups.ResultsIn the SVaD group, higher education was correlated with more severe cortical thinning in the bilateral dorsolateral frontal, left medial frontal, and parahippocampal areas, whereas there was no correlation of education with cortical thickness in the svMCI group. There was no correlation between education and cerebral small vessel disease, including WMH and lacunes, in both patients with svMCI and patients with SVaD.ConclusionsOur findings suggest that the compensatory effects of education on cortical thinning apply to patients with SVaD, which might be explained by the cognitive reserve hypothesis.

Neuropsychiatric characteristics of PiB-negative subcortical vascular dementia versus behavioral variant frontotemporal dementia

BackgroundNeuropsychiatric symptoms of subcortical vascular dementia (SVaD) are mainly associated with damage to frontal-subcortical circuits and may be similar to symptoms of behavioral variant frontotemporal dementia (bvFTD). The aim of this study was to determine whether the neuropsychiatric manifestations of the Pittsburgh compound B (PiB)-negative SVaD and bvFTD groups differ. MethodsWe compared the Caregiver-Administered Neuropsychiatry Inventory (CGA-NPI) between 48 patients with PiB(−) SVaD and 31 patients with bvFTD. A stepwise logistic regression was applied to determine the best model to predict SVaD. ResultsThe SVaD group showed a higher frequency of depression, whereas the bvFTD group had a higher frequency of elation, aberrant motor behavior and appetite/eating disorders. Regarding NPI subscores, the bvFTD group had greater severity of elation, apathy, disinhibition, aberrant motor behavior and appetite/eating disorders, whereas SVaD did not have significantly higher subscores in any domains. The most predictive models that tend to find suggestions of SVaD, as opposed to bvFTD, are as follows: (1) the presence of depression and the absence of appetite/eating disorders, (2) higher NPI subscores of depression and lower NPI subscores of irritability and aberrant motor behavior. ConclusionApart from apathy, SVaD differed from bvFTD in that negative symptoms were more common in SVaD than bvFTD, whereas positive symptoms were predominant in bvFTD compared to SVaD.

The Difference of Verbal Fluency Task Performance between Alzheimer’s Disease and Subcortical Vascular Dementia: CREDOS (Clinical Research Center for Dementia of South Korea) Study

Background: The verbal fluency test consists of two separate tests of semantic fluency and phonemic fluency. The performance patterns of these tests differ with the type of dementia. We studied the patterns of verbal fluency between Alzheimer's disease (AD) and subcortical vascular dementia (SVaD), and assessed the clinical utility of these tests. Methods: The 1,475 selected participants comprised 73 normal control sub jects, 673 patients with amnestic mild cognitive impairment (aMCI), 535 AD patients, 42 patients with subcortical vascular mild cognitive impairment (svMCI), and 152 SVaD patients. We analyzed the z-score for the total number of animal items as a semantic fluency index and the z-score of the phonemic total score as a phonemic fluency index. Results: The performance of semantic fluency was lower than that of phonemic fluency in all groups. The SVaD group showed the worst scores and abnormal performances on both tests, while the AD group presented abnormal performance only for semantic fluency. Dividing the patients with dementia according to severity revealed a different pattern between AD and SVaD for the clinical dementia rating (CDR) stage of 0.5. The performance of the AD group declined gradually with CDR. However, the SVaD group performed very poorly in both tests even for very mild dementia (CDR stage of 0.5). The aMCI and svMCI groups exhibited similar performance patterns. Conclusions: The pattern of semantic and phonemic fluency was not clinically useful at the MCI stage, but it could be helpful in differentiating AD and SVaD in the early stage of dementia. J Korean Neurol Assoc 34(1):14-22, 2016

White matter microstructural changes in pure Alzheimer's disease and subcortical vascular dementia.

Recent studies have demonstrated that Alzheimer's disease (AD) and subcortical vascular dementia (SVaD) have white matter (WM) microstructural changes. However, previous studies on AD and SVaD rarely eliminated the confounding effects of patients with mixed Alzheimer's and cerebrovascular disease pathologies. Therefore, our aim was to evaluate the divergent topography of WM microstructural changes in patients with pure AD and SVaD. Patients who were clinically diagnosed with AD and SVaD were prospectively recruited. Forty AD patients who were Pittsburgh compound B (PiB) positive [PiB(+) AD] without WM hyperintensities and 32 SVaD patients who were PiB negative [PiB(-) SVaD] were chosen. Fifty-six cognitively normal individuals were also recruited (NC). Tract-based spatial statistics of diffuse tensor imaging were used to compare patterns of fractional anisotropy (FA) and mean diffusivity (MD). Compared with the NC group, the PiB(+) AD group showed decreased FA in the bilateral frontal, temporal and parietal WM regions and the genu and splenium of the corpus callosum as well as increased MD in the left frontal and temporal WM region. PiB(-) SVaD patients showed decreased FA and increased MD in all WM regions. Direct comparison between PiB(+) AD and PiB(-) SVaD groups showed that the PiB(-) SVaD group had decreased FA across all WM regions and increased MD in all WM regions except occipital regions. Our findings suggest that pure AD and pure SVaD have divergent topography of WM microstructural changes including normal appearing WM.

NEUROPSI battery subtest profile in subcortical vascular dementia and Alzheimer's disease.

ObjectiveTo investigate the diagnostic value of subtests of the NEUROPSI battery for differentiating subcortical vascular dementia (SVaD) from Alzheimer's disease (AD).MethodsThirteen patients with mild SVaD, 15 patients with mild probable AD, and 30 healthy controls, matched for age, education and dementia severity (in the case of patients), were submitted to the Mini-Mental State Examination (MMSE) and NEUROPSI battery. The performance of AD and SVaD groups on NEUROPSI subtests was compared. The statistical analyses were performed using Kruskal-Wallis, Chi-square and Mann-Whitney tests. The results were interpreted at the 5% significance level (p<0.05). Bonferroni's correction was applied to multiple comparisons (α=0.02).ResultsSVaD and AD patients showed no statistical difference in MMSE scores (SVaD=20.8 and AD=21.0; p=1.0) or in NEUROPSI total score (SVaD=65.0 and AD=64.3; p=0.56), suggesting a similar severity of dementia. The AD group performed worse on memory recall (<0.01) and SVaD group was worse in verbal fluency subtests (p=0.02).ConclusionNEUROPSI's memory and language subtests can be an auxiliary tool for differentiating SVaD from AD.

Рівень білка S100В сироватки крові як маркер прогресування легких когнітивних порушень судинної етіології у субкортикальну судинну деменцію та ефективності терапевтичних впливів

We evaluated serum level of S100B in 11 patients with subcortical vascular dementia (SVD) and 19 patients with subcortical vascular mild cognitive impairment (SVMCI). Comparable groups were age-matched (79,18 ± 7,76 in SVD group, 77,84 ± 3,83 in SVMCI; Р = 0,53). 22 patients were as-sessed after 1 month therapy. It was shown that the serum S100B level significantly increased – (0,065 ± 0,020) μg/l (Р = 0,0005) in SVD patients comparing to SVMCI ones – (0,043 ± 0,010) μg/l. S100B level was significantly correlated with the clinical parameters: MMSE performance (rs = –0,61), CDR (rs = 0,58), attention task (rs = –0,46), pseudobulbar syndrome severity (rs = 0,37) and walking alteration (rs = 0,37). In patients with reduction of S100B level due to therapy (positive dynamics, n = 12) we registered significant improvement of some clinical parameters: MMSE, attention level, walking. In patients with increasing of S100B level (negative dynamics, n = 10) we didn’t registered improvement of any clinical parameters. We made the conclusion that the serum level of S100B could be used as marker of progression SVMCI into SVD and therapy effectiveness.

Cerebellar Atrophy in Patients with Subcortical-Type Vascular Cognitive Impairment

Recent studies suggest that the role of the cerebellum extends into cognitive regulation and that subcortical vascular dementia (SVaD) can result in cerebellar atrophy. However, there has been no evaluation of the cerebellar volume in the preclinical stage of SVaD. We aimed to compare cerebellar volume among patients with amnestic mild cognitive impairment (aMCI) and subcortical vascular mild cognitive impairment (svMCI) and evaluate which factors could have contributed to the cerebellar volume. Participants were composed of 355 patients with aMCI, svMCI, Alzheimer's disease (AD), and SVaD. Cerebellar volumes were measured using automated methods. A direct comparison of the cerebellar volume in SVaD and AD groups showed that the SVaD group had a statistically smaller cerebellar volume than the AD group. Additionally, the svMCI group had a smaller cerebellar volume than the aMCI group, with the number of lacunes (especially in the supratentorial regions) being associated with cerebellar volume. Cerebellar volumes were associated with some neuropsychological tests, digit span backward and ideomotor apraxia. These findings suggest that cerebellar atrophy may be useful in differentiating subtypes of dementia and the cerebellum plays a potential role in cognition.

Abstract 2986: Bilateral Thalamic Lesions in Subcortical Vascular Dementia

Subcortical vascular dementia (SVaD) is categorized to the group of dementia due to the small-vessel disease which consists of lacunar infarcts, microbleeds and leuko-araiosis. However, the causative lesions and their relationship have not been clarified yet in SVaD. In order to elucidate the pathophysiology underlying SVaD, MR findings and vascular risk factors were analyzed in 31 patients (25 men and 6 women) who were diagnosed as having SVaD based on the NINDS-AIREN criteria. Their mean age was 75.7 years. Thirty-six non-demented patients with asymptomatic cerebral infarction (ACI) and 49 non-demented patients with symptomatic lacunar infarcts (SCI) served as disease controls. All subjects underwent 1.5 Tesla MRI including T1WI, T2WI, T2*WI, FLAIR and MR angiography. Numbers of lacunar infarcts and old microbleeds were counted in all MR slices, and the degree of leuko-araiosis was evaluated according the Fazekas’ categories. Laboratory studies included fibrinogen, d-dimer, serum lipid profile, glucose, plasma immunoreactive insulin (IRI) and brain natriuretic peptide (BNP). In the neuropsychological evaluation, MMSE, clock drawing test (CDT) and Benton’s visual retention test (BVRT) were carried out. In the results, the mean MMSE score was 13.0, and the mean CDT was 2.7/5.0. In the MR findings, the mean number of lacunar infarcts was 11.4, 15.2 and 17.2 for ACI, SCI and SVaD group, respectively. Thalamic lesions were detected in 30 (96.8%) of 31 SVaD patients, and 86.6% were lacunar infarcts whereas 13.3% were microbleeds on T2*WI. Bilateral thalamic lesions were detected in 66.7%, and the right-side and left-side lesions were seen in 16.6%, respectively. Antero-medial thalamic lesion was detected in 23.3%. No bilateral thalamic lesions were found in ACI or SCI group. Microbleeds were detected in 90% of SVaD patients. The mean number of microbleeds was 1.3, 2.1 and 5.8 for ACI, SCI and SVaD group, respectively. In the laboratory studies, the mean fibrinogen was significantly greater in SVaD group than in ACI or SCI group. The mean insulin was significantly greater in SVaD group than in ACI and SCI group. Advanced leuko-araiosis (Grade II and III) was seen in 87.1% of SVaD patients, whereas 52.8% of ACI patients and 34.7% of SCI patients. In the laboratory studies, the mean fibrinogen, IRI and BNP were significantly greater in SVaD group than in ACI or SCI group (p&lt;0.05). The mean ratio of LDL-cholesterol to HDL-cholesterol was significantly greater in SVaD and SCI groups than in ACI group (p&lt;0.05). In the present results, thalamic lesions, especially bilateral thalamic lesions, were detected frequently in SVaD patients. As thalamus plays an important role in both medial limbic and basolateral limbic systems which mediate cognitive information processing including memory and emotion, thalamic lesions may redound to the formation of SVaD.

Characteristics of mini-mental status examination in subtype of mild cognitive impairment: Using a decision tree analysis

Background: Previous studies reported that apathy was shown in almost half of sub cortical vascular dementia (SVD) and Alzheimer’s disease (AD) patients, and in 15% of mild cognitive impairment (MCI) subjects. Our aim is to elucidate the differences of clinical features of apathy between very mild SVD (vm SVD) and very mild AD (vm AD) subjects. Methods: We obtained the agreement from 200 community dwellers, aged 75+ years living in Kurihara, Northern Japan. We utilized clinical examination, Clinical Dementia Rating (CDR), MRI, blood tests and neuropsychological tests. Of the 200 subjects, there were 57 with a CDR 0 (healthy), 111 with a CDR 0.5 (MCI), and 32 with a CDR 1+ (dementia). We divided CDR 0.5 subjects into 3 groups, 12 with vm SVD, 38 with vm AD and 61 with other types. All vm SVD subjects met the Erkinjuntti’s criteria; memory deficits, executive function disturbances, neurological signs present and lacunar infarctions in basal ganglia or white matter hyper intensity on MRI. All vm AD subjects met possible AD as per the NINCDS-ADRDA criteria. They showed no cerebral infarctions, no neurological signs, or no abnormalities of blood test causing dementia. The two CDR 0.5 groups diagnosed as vm SVD and vm AD were compared. There were no significant differences between the two groups for age, sex, educational level, MMSE (22.2 v.s. 22.8) and Geriatric Depression Scale (5.3 v.s. 3.8). To assess apathy, we used the Clinical Assessment for Spontaneity part 3 (CAS3) which estimated their apathy through a questionnaire given to each subject’s caregiver. We examined the differences between the two groups for CDR domains; Community Affairs (CA), Home and Hobbies (HH) and Personal Care (PC), and CAS3. Results: There were no significant differences between the vm SVD and vm AD groups in CA, HH and PC. However, the apathy score of the vm SVD group was severer than the vm AD group in CAS3 (3.8 v.s. 2.0, p1⁄40.02). Conclusions: The results suggest that vm SVD subjects have severer apathy compared with vm AD subjects. Earlier therapeutic intervention would be needed for vm SVD patients who showed apathy in a community.

Differential Diagnosis of Idiopathic Normal Pressure Hydrocephalus from Other Dementias Using Diffusion Tensor Imaging

Because DTI can provide good markers of white matter pathology, it could be useful in differentiating white matter changes of INPH from those of other dementias. The aim of this study was, by using DTI, to compare the characteristic white matter changes in INPH with those in AD, subcortical vascular dementia, and healthy control subjects. Sixteen patients with presurgical INPH, 10 with AD, 10 with subcortical vascular dementia, and 20 healthy control subjects underwent DTI. All patients with INPH showed clinical improvement after shunt surgery, and 9 of them also underwent postshunting DTI. Regions of interest were selected at the periventricular white matter, the anterior limb of the internal capsule, the posterior limb of the internal capsule, the genu and the splenium of the corpus callosum, the superior longitudinal fasciculus, and the inferior longitudinal fasciculus. FA and MD were obtained from each region of interest and were compared among the groups. Presurgical INPH showed significantly higher FA than all the other groups in the posterior limb of the internal capsule, which was decreased after shunt surgery. Presurgical MD of the INPH group was higher than that in the AD and healthy control groups but lower than that in the subcortical vascular dementia group in the anterior periventricular white matter, the anterior limb of the internal capsule, and the superior longitudinal fasciculus. In differentiating INPH, the sensitivity and specificity of FA in the posterior limb of the internal capsule was 87.5% and 95.0%, respectively. Patients with shunt-responsive INPH showed higher FA in the posterior limb of the internal capsule compared with healthy controls and those in other groups of dementia that was reversible with shunt surgery. With this parameter, shunt-responsive INPH could be distinguished from AD, subcortical vascular dementia, and healthy conditions with high diagnostic accuracy.

Are the Indices of the RBANS Sufficient for Differentiating Alzheimer's Disease and Subcortical Vascular Dementia?

Alzheimer's disease (AD) and subcortical vascular dementia (SVaD) are among the most prevalent dementias and they often show specific patterns of cognitive dysfunction. This study examined whether differences exist between groups on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) that could assist with differential diagnosis. The examiners utilized the NINCDS-ADRDA and the NINDS-AIREN criteria to identify 39 probable AD and 29 probable SVaD patients. A battery of neuropsychological tests was performed and neuroimaging was reviewed for all subjects. Analyses revealed that the SVaD group performed significantly better on the Delayed Memory Index (DMI) and its subtests measuring Recognition, Contextual Memory, and Figure Recall. In contrast to previous research, there were no differences between groups on immediate memory tasks, and post hoc analyses revealed no differences on any other index or subtest. The results also suggested that the DMI and its subtests and the Story Memory subtest of the Immediate Memory Index have better sensitivity to AD, better specificity to SVaD, and roughly equivalent positive predictive power compared with other components of the RBANS. Overall, findings suggest that the indices and subtests of the RBANS may be limited in differentiating AD versus SVaD, except for the DMI and its subtests.

Relationships between 24-Hour Blood Pressures, Subcortical Ischemic Lesions, and Cognitive Impairment

Background and PurposeThe most important treatment for subcortical vascular dementia (SVaD) is controlling the blood pressure (BP). However, the few studies that have investigated the relationships between diurnal BP rhythm and subcortical ischemic vascular cognitive impairment have produced inconclusive results. In the study presented here, the 24-hour BP values of three groups of subjects-patients with subcortical vascular mild cognitive impairment (SvMCI), patients with SVaD, and normal controls-were compared using working criteria and 24-hour ambulatory BP (ABP) monitoring.MethodsThe subjects (42 patients with SVaD, 37 patients with SvMCI, and 30 controls) were selected according to the study's inclusion/exclusion criteria. All subjects underwent brain magnetic resonance (MR) imaging and MR angiography, detailed neuropsychological testing, and 24-hour ABP monitoring.ResultsThe prevalence of nondippers differed markedly between the control group and both the SVaD and SvMCI groups. Loss of nocturnal dipping was significantly associated with SVaD [odds ratio (OR), 4.827; 95% confidence interval (CI), 1.07-12.05].ConclusionsIt was found that SVaD is associated with loss of nocturnal BP dipping combined with increased pulse pressure and systolic BP (SBP) variability. Correction of these factors could therefore be important in the prevention of SVaD, independent of measures used to reduce BP.

Does EEG (visual and quantitative) reflect mental impairment in subcortical vascular dementia?

The aim of this study was to determine if the results of visual and quantitative EEG (QEEG) parameters reveal a correlation with mental impairment in subcortical vascular dementia (SVD), one of the most frequent causes of cognitive impairment in the elderly. In SVD, like in Alzheimer's disease disturbances were found in cholinergic transmission. The cholinergic deficit as manifested in changes of synaptic potentials is reflected in EEG signals. Material 31 patients with probable SVD (according to NINCDS-AIREN and T. Erkinjuntii's criteria) and mean age 72.3 yrs;(M—43%, F—57%) and 14 healthy control subjects with mean age of 72.3 yrs (M—57%, F—43%). According to the Mini Mental Scale Examination (MMSE) the SVD group was divided into two subgroups with mild and moderate dementia, their EEGs being recorded with a Medelec and Neuroscan 4.2 system. Visual EEG findings were classified with the use of eight-degree scale of pathological changes by the presence of slow waves. Then QEEGs were made. The following parameters were calculated: alpha/slow wave power ratios, the mean wave frequency in all and in some selected derivations. Results A significant difference was found between QEEGs in SVD subgroups with mild and moderate dementia ( p < 0.05), but there was no significant difference between visual EEGs. A significant correlation between QEEG parameters such as alpha/slow wave ratio or mean wave frequency and mental impairment (according to MMSE results) was found ( p < 0.001), but there was no significant correlation between degree of EEG abnormalities in visual analysis and MMSE results. Conclusion Only QEEGs are correlated with mental impairment in SVD. Visual EEG technique as a less precise tool does not reflect the mental impairment in SVD due to cholinergic deficit.

Decreased Cerebrospinal Fluid Acetylcholinesterase in Patients with Subcortical Ischemic Vascular Dementia

The main objective was to investigate the acetylcholinesterase E (AChE) activity in the cerebrospinal fluid (CSF) of patients with three common dementia disorders. We also wanted to investigate the influence of apolipoprotein E (ApoE) Ε4 allele possession and CSF-τ level on the CSF-AChE activity in these patients. The study included 17 consecutive patients with subcortical vascular dementia (SVD), 39 with Alzheimer’s disease (AD), 14 with frontotemporal dementia (FTD) and 12 controls. CSF was obtained by lumbar puncture and CSF-AChE activity was measured by an enzyme antigen immunoassay. CSF-AchE activity was significantly decreased compared to controls only in the SVD group (p = 0.010). The CSF-τ level was increased in the AD group compared to the control (p < 0.01) and FTD groups (p < 0.05). No influence of ApoE Ε4 allele possession on CSF-AChE activity was found. It is suggested that abnormal CSF-AChE activity in patients with SVD reflects a disturbance in the cholinergic system.

Differential episodic and semantic memory performance in Alzheimer's disease and vascular dementias.

Differential performance on measures of episodic and semantic memory were examined in AD, cortical vascular dementia (CVaD), subcortica] vascular dementia (SVaD), and controls. Groups were matched on age, education, and gender; dementia groups also were matched on severity. Recognition/retrieval differences were found only between SVaD and AD groups, not between CVaD and AD. Thus, recognition/retrieval differences are likely secondary to subcortical pathology rather than to vascular etiology per se. Similarly, significant numbers of memory errors were associated with cortical pathology, regardless of etiology. Error rate differences were found only between SVaD and AD groups, not between CVaD and AD. Finally, rapid forgetting was unique to AD; however, since no difference was found between SVaD and AD, rapid forgetting may occur only as AD progresses. No semantic memory measure differentiated AD from either CVaD or SVaD subjects. Results suggest that some previously reported episodic differences may be due to cortical versus white matter subcortical pathology, rather than to AD versus vascular etiology.