Riitta Mäntylä

Comparison of Different Clinical Criteria (DSM-III, ADDTC, ICD-10, NINDS-AIREN, DSM-IV) for the Diagnosis of Vascular Dementia

Background and Purpose The criteria for vascular dementia (VaD) include definition of the cognitive syndrome and the vascular cause. Different criteria for dementia identify different frequencies and clusters of patients. In addition, variation in defining the cause and etiology may have an effect. We compared different clinical criteria for VaD in series of patients with poststroke dementia. Methods The study group comprised 107 patients fulfilling the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III) definition for dementia from a cohort of consecutive patients with ischemic stroke who completed a comprehensive neuropsychological test battery and MRI. The mean age (SD) of the patients was 71.4 (7.6) years. The definitions of vascular cause of VaD were those of the DSM-III (1980), Alzheimer’s Disease Diagnostic and Treatment Centers (ADDTC; 1992), International Statistical Classification of Diseases, 10th Revision (ICD-10; 1992), National Institute of Neurological Disorders and Stroke–Association Internationale pour la Recherche et l’Enseignement en Neurosciences (NINDS-AIREN; 1993), and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; 1994). Results The number of cases that could be classified as VaD according to the different criteria varied considerably: 36.4% (n=39) by DSM-III, 86.9% (n=93) by ADDTC, 32.7% (n=35) by NINDS-AIREN, 36.4% (n=39) by ICD-10, and 91.6% (n=98) by DSM-IV criteria. The concordance between DSM-III/ICD-10 was perfect (100%; &kgr;=1.0), between ICD-10/NINDS-AIREN and ADDTC/DSM-IV good to moderate (85.0% and 87.3%; &kgr;=0.87 and 0.37, respectively), but otherwise poor between the other criteria. Only 31 patients fulfilled all the criteria for VaD applied. Major discriminating factors between the criteria were requirement of (1) focal neurological signs, (2) unequal distribution of deficits in higher cortical functions, and (3) evidence of relevant CVD based on brain imaging findings. Conclusions Current criteria of VaD identify different frequencies and clusters of patients and are not interchangeable. Optimally, prospective studies with clinicopathological correlation could identify new criteria. Meanwhile, focus on more homogeneous subtypes (eg, small-vessel subcortical VaD) and detailed neuroimaging criteria could improve the diagnostics.

Cognitive profile of subcortical ischaemic vascular disease

Objectives: Subcortical ischaemic vascular disease (SIVD) is a subtype of vascular cognitive impairment characterised by extensive white matter lesions and multiple lacunar infarcts. Radiologically defined diagnostic criteria for SIVD have been introduced, but only a few studies have presented empirical data on its clinical and cognitive features. The aim of this study is to describe in detail the neuropsychological characteristics of patients with SIVD from a large well defined stroke cohort. Methods: A sample of 323 consecutive patients with ischaemic stroke, aged 55–85 years, was investigated using neuropsychological examination and magnetic resonance imaging (MRI). Patients fulfilling the MRI criteria of SIVD (n = 85) were compared to the other stroke patients (n = 238) and to normal control subjects (n = 38). Results: Cognitive performance of the SIVD group was inferior to that of the normal control group throughout all domains. As compared to the other stroke patients, the SIVD group performed significantly worse in tests measuring executive functions and delayed memory recall. Adjusting for depression had no effect on these results. Instead, after controlling for medial temporal lobe atrophy, the differences disappeared for delayed memory but remained significant for executive functions. Conclusion: Executive deficits are the most prominent cognitive characteristic associated with SIVD. Patients with SIVD also exhibit subtle deficits in delayed memory, which is explained in part by medial temporal lobe atrophy. Cognitive and mood changes seem to be parallel but independent processes related to SIVD. The results support the concept of SIVD as a separate clinical entity.

White matter hyperintensities as a predictor of neuropsychological deficits post-stroke

Objectives: Cerebral white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) are a recognised risk factor for post-stroke dementia. Their specific relations to cognitive impairment are still not well known. The purpose of this study was to explore how the severity and location of WMHs predict neuropsychological test performance in the context of other brain lesions in elderly stroke patients. Methods: In the Helsinki Stroke Aging Memory Study, 323 patients, aged from 55 to 85 years, completed a detailed neuropsychological test battery and MRI 3 months after an ischaemic stroke. The demographic and MRI predictors of cognition were studied with sequential linear regression analyses. Results: After age, education and total infarct volume were controlled for, the overall degree of WMHs predicted poor performance in tests of mental speed, executive functions, memory, and visuospatial functions, but not in those of short term memory storage or verbal conceptualisation. However, the contribution of separate white matter regions was relatively low. Only the lesions along the bodies of lateral ventricles were independently associated with speed and executive measures. Additionally, general cortical atrophy clearly predicted a wide range of cognitive deficits while infarct volume had less relevance. Further analyses revealed that executive functions act as a strong mediator between the relationship of WMHs to memory and visuospatial functions. Conclusions: The degree of WMHs is independently related to post-stroke cognitive decline. The most affected cognitive domains seem to be executive functions and speed of mental processing, which may lead to secondary deficits of memory and visuospatial functions.

Magnetic Resonance Imaging White Matter Hyperintensities and Mechanism of Ischemic Stroke

BACKGROUND AND PURPOSE We sought to determine the relations between infarct subtype and white matter hyperintensities (WMHIs) on MRI. MATERIALS AND METHODS We studied 395 ischemic stroke patients with 1. 0-T MRI. The number of lacunar, border-zone, and cortical infarcts was registered. WMHIs were analyzed in 6 areas. Univariate and multivariate statistical analyses were used to find the risk factors for different infarct subtypes and to study the connections between WMHIs and brain infarcts. RESULTS Lacunar infarcts were associated with hypertension (odds ratio [OR], 1.79; 95% CI, 1.17 to 2.73), alcohol consumption (OR, 1.96; 95% CI, 1.17 to 3.28), and age (OR, 1. 03; 95% CI, 1.00 to 1.06). Border-zone infarcts were associated with carotid atherosclerosis (OR, 2.20; 95% CI, 1.15 to 4.19). Atrial fibrillation (OR, 3.02; 95% CI, 1.66 to 5.50) and carotid atherosclerosis (OR, 1.94; 95% CI, 1.12 to 3.36) were independent positive predictors, and history of hyperlipidemia (OR, 0.44; 95% CI, 0.26 to 0.75) and migraine (OR, 0.48; 95% CI, 0.25 to 0.93) were negative predictors for cortical infarcts. Patients with lacunar infarcts had more severe WMHIs than patients with nonlacunar infarcts in all WM areas (P</=0.001). Patients with border-zone infarcts showed severe periventricular lesions (P=0.002), especially around posterior horns (P=0.003). The extent of WMHIs in patients with cortical infarcts did not differ from that in those without cortical infarcts. CONCLUSIONS Various infarct subtypes have different risk profiles. The association between lacunar infarcts and WMHIs supports the concept of small-vessel disease underlying these 2 phenomena. The connection between border-zone infarcts and periventricular WMHIs again raises the question of the disputed periventricular vascular border zone.

MRI correlates of executive dysfunction in patients with ischaemic stroke

Executive dysfunction (ED) may lead to problem behaviour and impaired activities of daily living in many neuropsychiatric disorders, but the neuroanatomical correlates of ED are still not well known. Different aspects of executive functions were studied by widely used neuropsychological tests in 214 elderly patients 3 months after ischaemic stroke, and a sum score of eight different measures was counted in each patient. The number and site of brain infarcts as well as severity and location of white matter lesions (WMLs) and brain atrophy on magnetic resonance imaging were recorded and compared between patients with and without ED. ED was present in 73 (34.1%) of the 214 patients. The mean frequency of brain infarcts in the brain and in the left hemisphere was higher in the patients with ED. Lesions affecting the frontal‐subcortical circuits (e.g. pallidum, corona radiata or centrum semiovale) were more frequent in patients with ED than in those without. Also, patients with pontine brain infarcts frequently had ED, but this may have been due to more extensive ischaemic changes in these patients in general. Mean number of brain infarcts affecting the pons and posterior centrum semiovale on the left side, moderate to severe medial temporal atrophy, the Fazekas white matter score, the Mini‐Mental State Examination score and low education were independent correlates of ED. Brain infarcts and WML affecting the frontal‐subcortical circuits or the pons may increase risk for ED in stroke patients.

Clinical and radiological determinants of prestroke cognitive decline in a stroke cohort

OBJECTIVES Stroke seems to be related to dementia more often than previously assumed and vascular factors are also related to Alzheimers disease. The pathophysiology of poststroke dementia includes ischaemic changes in the brain, a combination of degenerative and vascular changes, and changes only related to Alzheimers disease. Some cognitive decline recognised after a stroke may be due to pre-existing cognitive decline. The aim of this study was to determine the clinical and radiological determinants of prestroke cognitive decline. METHODS The study group comprised 337 of 486 consecutive patients aged 55 to 85 years who 3 months after ischaemic stroke completed a comprehensive neuropsychological test battery; structured medical, neurological, and mental status examination; interview of a knowledgeable informant containing structured questions on abnormality in the cognitive functions; assessment of social functions before the index stroke; and MRI. RESULTS Frequency of prestroke cognitive decline including that of dementia was 9.2% (31/337). The patients with prestroke cognitive decline were older, more often had less than 6 years of education, and had history of previous stroke. Vascular risk factors did not differ significantly between these two groups. White matter changes (p=0.004), cortical entorhinal, hippocampal, and medial temporal atrophy (p<0.001), cortical frontal atrophy (p=0.008); and any central atrophy (p<0.01), but not the frequencies or volumes of old, silent, or all infarcts on MRI differentiated those with and without prestroke cognitive decline. The correlates of prestroke cognitive decline in logistic regression analysis were medial temporal cortical atrophy (odds ratio (OR) 7.5, 95% confidence interval (95%CI) 3.2–18.2), history of previous ischaemic stroke (OR 4.4, 95% CI 1.8–10.6), and education (OR 0.9, 95% CI 0.8–0.9). CONCLUSIONS History of previous stroke, but not volumes or frequencies was found to correlate with prestroke cognitive decline. Other associating factors were rather those usually associated with degenerative dementia: white matter changes and cerebral atrophy; and in multiple models medial temporal cortical atrophy and education. The possible overlap between two or more underlying diseases must be remembered in diagnosis and treatment of patients with vascular cognitive impairment.

Depression-executive dysfunction syndrome in stroke patients.

OBJECTIVE It has been suggested that executive dysfunction could be the core defect in patients with geriatric or vascular depression, and that this depression-dysexecutive syndrome (DES) might be related to frontal-subcortical circuit dysfunction. The authors tested this hypothesis in 158 poststroke patients, of whom 21 had both depression and executive dysfunction. METHODS In this cross-sectional cohort study, a neurological, psychiatric, and neuropsychological examination was carried out 3 months after ischemic stroke, and brain infarcts, white-matter changes, and brain atrophy were recorded by MRI. RESULTS The 21 patients with DES had significantly more brain infarcts affecting their frontal-subcortical circuit structures than the 137 patients without DES, or the 41 patients with depression but without executive dysfunction. Patients with DES also had more severe depressive symptoms and worse psychosocial functioning, and they coped less well in complex activities of daily living. CONCLUSIONS DES is a valid concept and may define a subgroup of poststroke patients with frontal-subcortical pathology and with distinct prognosis and treatment options.

Fibrinogen Gene Promoter −455 A Allele as a Risk Factor for Lacunar Stroke

Background and Purpose— Elevated fibrinogen levels are suggested to increase the risk of myocardial infarction and stroke. Carriers of the A allele of the fibrinogen −455G/A polymorphism have increased plasma fibrinogen levels. We studied the association of this polymorphism with stroke subtype in the Stroke Aging Memory (SAM) cohort. Methods— The SAM cohort comprises 486 consecutive patients 55 to 85 years of age who, 3 months after ischemic stroke, completed a detailed stroke assessment. Stroke subtypes were examined with MRI. −455G/A genotype was determined by polymerase chain reaction. MRI and genotype data were available for the 299 patients who constitute the present study population. Results— Genotype distributions were 64.9% (GG), 31.8% (GA), and 3.3% (AA). In a logistic regression model with age, sex, hypertension, diabetes, hypercholesterolemia, hypertriglyceridemia, myocardial infarction, arrhythmia, atrial fibrillation, peripheral arterial disease, and smoking as possible confounders, there was a significant association between A+ genotype and ≥3 lacunar infarcts (odds ratio [OR], 2.57; 95% CI, 1.23 to 5.36;P =0.01). Hypertensive patients carrying the A allele had increased risk (OR, 4.24; 95% CI, 1.29 to 13.99;P =0.02) for ≥3 lacunar infarcts. A similar increase in risk was observed among smokers with the A+ genotype (OR, 2.67; 95% CI, 0.92 to 7.77;P =0.07). Conclusions— Stroke patients carrying the A allele of the B&bgr;-fibrinogen −455G/A polymorphism frequently presented with multiple lacunar infarcts. This association was stronger among hypertensives and smokers. These associations suggest that the A allele may predispose to atherothrombotic events in cerebrovascular circulation.

Clinical features of MRI-defined subcortical vascular disease.

Background and PurposeVascular cognitive impairment and vascular dementia are now seen to extend much beyond the traditional multi-infarct dementia.A more homogeneous subtype is the subcortical ischemic vascular disease (SIVD). We applied magnetic resonance imaging (MRI) criteria based on research criteria for SIVD in a large cohort of patients with ischemic stroke. We compared clinical features of patients with SIVD and patients with other stroke type. Subject and MethodsThe study group comprised 337 of 486 consecutive patients aged 55 to 85 years who 3 months after ischemic stroke completed a comprehensive neuropsychological test battery and MRI, including structured medical, neurologic, and laboratory evaluations; clinical mental status examination; interview of a knowledgeable informant; detailed history of risk factors; and evaluation of stroke type, localization, and syndrome. ResultsPatients with SIVD (n = 86) more often had a history of progressive cognitive decline (22.8% vs. 6.9%, P = 0.0002), walking disorder before stroke (27.9% vs. 2.0%, P = 0.02), and urinary difficulties (12.8% vs. 5.6%, P = 0.028) in comparison with patients with other stroke type (n = 251). Of the study population, 107 (31.8%) had DSM-III dementia. The patients with SIVD more often had DSM-III dementia (40.7% vs. 28.7%, P = 0.04), had less severe stroke as measured by Scandinavian Stroke Scale (56.6 vs. 55.1, P = 0.03), were more dependent in activities of daily living (ADL) functions as measured by FAQ scale (8.9 vs. 5.4, P = 0.001), were more dependent in instrumental activities of daily living (IADL) functions as measured by the Lawton scale (5.5 vs. 6.3, P = 0.01), and were more depressed as measured by the Beck Depression Inventory (11.8 vs. 8.4, P = 0.0003) poststroke than the patients without SIVD. The main cognitive domain that differentiated the patients with SIVD from those without was executive dysfunction (51.2% vs. 38.7%, P = 0.04). According to multiple regression model, apractic-atactic gait disorder (odds ratio 2.82, 95% confidence interval 1.21–6.53), ADL functions (odds ratio 1.04, 95% confidence interval 1.01–1.08), and the Beck Depression Inventory (odds ratio 1.05, 95% confidence interval 1.02–1.09) related to SIVD. ConclusionsThe most significant clinical features of MRI-defined SIVD were found to be apractic-atactic gait, impaired ADL functions, and depression.

Medial temporal lobe atrophy and memory deficits in elderly stroke patients

Medial temporal lobe atrophy (MTA) and its role in memory deficits have been studied extensively in patients with various dementias and non‐degenerative neurologic diseases. In stroke patients MTA is a significant risk factor for dementia. However, its role in memory decline in non‐demented stroke patients is not yet known. Our aim was to evaluate the relationship between MTA and cognitive functions in a large cohort of elderly patients, who underwent a comprehensive neuropsychologic examination and magnetic resonance imaging 3 months after an ischemic stroke. The study sample (n = 260) was divided into three groups according to the severity of MTA. After adjusting for age, volume of infarcts and cortical atrophy, we found that patients with moderate to severe MTA performed significantly worse in tests of learning, story recall, visual reproduction, block design and mental speed. In contrast, the groups did not differ in tests of digit span, flexibility, verbal fluency and conceptualization. Our conclusion is that in aged stroke patients, MTA is associated with poor performance in specific cognitive domains. The most vulnerable domains are memory and visuospatial functions, whereas verbal and executive functions seem to be unrelated to MTA.