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T Hänninen

Publications and source records attributed to T Hänninen.

At least 19 recordsLinked to original sources
PubMed2002

Prevalence of mild cognitive impairment: a population-based study in elderly subjects.

OBJECTIVES: Mild cognitive impairment (MCI) has been suggested as a term for a boundary area between normal aging and dementia, especially Alzheimer's disease (AD). In follow-up studies, more than 50% of MCI subjects have been converted to dementia in 3-4 years. However, the epidemiology of MCI is not well known. This study was designed to determine the prevalence of MCI in an elderly population. METHODS: A total of 806 subjects (60-76 years of age) from a population-based random sample of 1150 subjects living in the city of Kuopio in eastern Finland were evaluated. Neuropsychological tests and a structured interview including the modified Clinical Dementia Rating (CDR) were used to apply the diagnostic criteria of MCI as proposed by Mayo Clinic Alzheimer's Disease Research Centre. Thus, subjects having a test score more than 1.5 SDs below the age appropriate mean in memory tests and a CDR score of 0.5 but no dementia, were diagnosed as having MCI. RESULTS: A total of 43 subjects, 5.3%, met the MCI criteria. MCI was more prevalent in older and less-educated subjects, but no difference was found between men and women. The CDR appeared to be the most important part of the criteria. The memory tests had less impact on prevalence variables. CONCLUSIONS: The low prevalence of MCI indicate that in a population-based study design its criteria may identify a more homogeneous group of subjects at the lower end of the cognitive continuum as contrasted with various other criteria of cognitive impairment in the elderly population. This is compatible with follow-up studies showing a high probability of dementia in the MCI group. Thus, probable candidates for trials of preventive intervention for dementia can be screened from the elderly population using these diagnostic criteria.

Aged↗
PubMed2001

Midlife vascular risk factors and late-life mild cognitive impairment: A population-based study.

OBJECTIVE: To evaluate the impact of midlife elevated serum cholesterol levels and blood pressure on the subsequent development of mild cognitive impairment (MCI) and to investigate the prevalence of MCI in elderly Finnish population, applying the MCI criteria devised by the Mayo Clinic Alzheimer's Disease Research Center. BACKGROUND: MCI has been considered as a predictor of AD. Vascular risk factors may be important in the development of cognitive impairment and AD. However, the role of vascular risk factors in MCI and the prevalence of MCI still remain virtually unknown. METHODS: Subjects were derived from random, population-based samples previously studied in surveys carried out in 1972, 1977, 1982, and 1987. After an average follow-up of 21 years, 1,449 subjects aged 65 to 79 years were reexamined in 1998. RESULTS: Eighty-two subjects, 6.1% of the population (average age, 72 years) met the criteria for MCI. Midlife elevated serum cholesterol level (> or =6.5 mmol/L) was a significant risk factor for MCI (OR, 1.9; 95% CI, 1.2 to 3.0, adjusted for age and body mass index); the effect of systolic blood pressure approached significance. CONCLUSION: Data point to a role for midlife vascular risk factors in the development of MCI in late life.

Aged↗
PubMed2001

Midlife vascular risk factors and Alzheimer's disease in later life: longitudinal, population based study.

OBJECTIVE: To examine the relation of midlife raised blood pressure and serum cholesterol concentrations to Alzheimer's disease in later life. DESIGN: Prospective, population based study. SETTING: Populations of Kuopio and Joensuu, eastern Finland. PARTICIPANTS: Participants were derived from random, population based samples previously studied in a survey carried out in 1972, 1977, 1982, or 1987. After an average of 21 years' follow up, a total of 1449 (73%) participants aged 65-79 took part in the re-examination in 1998. MAIN OUTCOME MEASURES: Midlife blood pressure and cholesterol concentrations and development of Alzheimer's disease in later life. RESULTS: People with raised systolic blood pressure (>/=160 mm Hg) or high serum cholesterol concentration (>/=6.5 mmol/l) in midlife had a significantly higher risk of Alzheimer's disease in later life, even after adjustment for age, body mass index, education, vascular events, smoking status, and alcohol consumption, than those with normal systolic blood pressure (odds ratio 2.3, 95% confidence interval 1.0 to 5.5) or serum cholesterol (odds ratio 2.1, 1.0 to 4.4). Participants with both of these risk factors in midlife had a significantly higher risk of developing Alzheimer's disease than those with either of the risk factors alone (odds ratio 3.5, 1.6 to 7.9). Diastolic blood pressure in midlife had no significant effect on the risk of Alzheimer's disease. CONCLUSION: Raised systolic blood pressure and high serum cholesterol concentration, and in particular the combination of these risks, in midlife increase the risk of Alzheimer's disease in later life.

Adult↗
PubMed2001

APOE-epsilon4 is associated with weight loss in women with AD: a population-based study.

OBJECTIVE: To investigate whether the APOE-epsilon4 allele is associated with weight loss in patients with AD or in nondemented elderly subjects. BACKGROUND: Weight loss has been considered a typical feature of AD. APOE-epsilon4 is a risk factor for AD and was recently proposed to be associated with weight loss in elderly women. It is not known whether APOE-epsilon4 is associated with weight loss in patients with AD or in the general population. METHODS: Weight and BMI measurements at an average interval of 3.5 years and APOE phenotype determination were performed in an elderly population (n = 980), including 46 patients with AD and 911 control subjects at the end of the follow-up. RESULTS: On average, patients with AD with the epsilon4 allele lost 1.9 +/- 4.0 kg (BMI 0.8 +/- 1.8 kg/m2) whereas epsilon4 noncarriers gained 1.2 +/- 3.8 kg (BMI 0.4 +/- 1.5 kg/m2) (both p < 0.05), after controlling for diabetes and exercise. However, when men and women were analyzed separately, weight loss was observed only in those women with AD with the epsilon4 allele. Clinically significant weight loss, defined as loss of > or = 5% of body weight, occurred more frequently in both patients with AD (30% versus 6%; p < 0.05) and control subjects (28% versus 18%; p < 0.001) carrying the epsilon4 allele. CONCLUSIONS: The APOE-epsilon4 allele may contribute to the unexplained weight loss in AD, especially in women.

Aged↗
PubMed2001

Mood improvement reduces memory complaints in depressed patients.

BACKGROUND: The aim was to examine associations between memory complaints, cognitive performance and mood in 174 adult, clinically depressed, neurologically healthy patients at baseline and during six months of follow-up. METHODS: Subjective memory disturbance was assessed using the Memory Complaint Questionnaire (MCQ). Levels of cognitive function, including memory, were assessed using a battery of neuropsychological tests. Mood and personality traits were assessed using rating scales, including the Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HDRS) and the 90-item Symptom Check List (SCL-90). RESULTS: At baseline, patients complaining of memory disturbances had higher BDI and HDRS scores than patients not complaining of memory problems. They also did less well in objective memory performances but not in other cognitive functions. Complaints of memory problems decreased during the follow-up. This change was associated with mood improvement and with reductions in other mental symptoms but not with changes in cognitive performance. In logistic regression analysis factors independently associated with MCQ change were age (OR 0.96) and BDI change (OR 1.06). CONCLUSIONS: Subjective memory problems usually decline if depression is alleviated.

Adult↗
PubMed2000

Diagnosis of Alzheimer's disease: MRI of the hippocampus vs delayed recall.

Hippocampal volume measurements using magnetic resonance imaging (MRI) and assessment of performance in tests of delayed recall are among the most useful aids for diagnosing early Alzheimer's disease (AD) on an individual level. However, their comparative diagnostic accuracy has not been previously addressed. In this study we compared the diagnostic accuracy of these two methods in 57 patients with probable AD according to the NINCDS-ADRDA criteria, and 34 age- and gender-matched control subjects. The discriminatory power of the hippocampal volumes and delayed recall performance, Russel's Adaptation of the Visual Reproduction Test (VRT), were compared in discrimination function and receiver operator characteristic analyses. Right and left hippocampal volumes resulted in correct classification of 85.7-86.8% of the study subjects, respectively, while performance in the VRT resulted in correct classification of 93.4% of subjects. The area under curve value was 0.93 for the left hippocampus and 0.96 for the VRT. These data suggest that assessment of delayed recall with the VRT is of high diagnostic accuracy, and may surpass the diagnostic accuracy of hippocampal volumetry.

Adaptation, Psychological↗
PubMed2000

Molecular evolution of puumala hantavirus in Fennoscandia: phylogenetic analysis of strains from two recolonization routes, Karelia and Denmark.

Like other members of the genus HANTAVIRUS: in the family BUNYAVIRIDAE:, Puumala virus (PUUV) is thought to be co-evolving with its natural host, the bank vole Clethrionomys glareolus. To gain insight into the evolutionary history of PUUV in northern Europe during the last post-glacial period, we have studied wild-type PUUV strains originating from areas along two postulated immigration routes of bank voles to Fennoscandia. Full-length sequences of the S RNA segment and partial sequences (nt 2168-2569) of the M segment were recovered by RT-PCR directly from bank vole tissues collected at three locations in Russian Karelia and one location in Denmark. Phylogenetic analysis showed that strains from Karelia and Finland belong to the same genetic lineage, supporting the hypothesis that PUUV spread to present Finland via a Karelian land-bridge. The Danish PUUV strains showed no particularly close relatedness to any of the known PUUV strains and formed a distinct phylogenetic lineage on trees calculated for both S and M segment sequences. Although no direct link between the Danish PUUV strains and those of the southern Scandinavian lineage was found, within the S segment of Danish PUUV strains, two regions with higher similarity to either northern Scandinavian or - to a less extent - southern Scandinavian genetic lineages were revealed, suggesting evolutionary connections of their precursors.

Amino Acid Sequence↗
PubMed2000

Verbal fluency activates the left medial temporal lobe: a functional magnetic resonance imaging study.

Verbal fluency tests (VFTs) are suggested to assess frontal lobe function. This view is supported by functional imaging studies that report left frontal activation during VFTs. VFTs require retrieval of semantically associated words from long-term memory storage. The neural networks that participate in this process, however, are largely unknown. These neural networks are of interest, given that patients with early Alzheimer's disease, typically without frontal pathology, are often impaired in VFTs. In the present study, functional magnetic resonance imaging was performed to determine brain activation areas during VFTs in young subjects. In the activation task, category fluency was contrasted with orderly listing of numbers. As judged from using this comparison, there was activation in the left medial temporal lobe, in the inferior frontal and retrosplenial cortices bilaterally, and in the left superior parietal lobule. Left medial temporal lobe activation was present in 13 of the 14 study subjects either in the hippocampal formation (11 of 14) or in the posterior parahippocampal gyrus (12 of 14). These results suggest that the medial temporal lobe is required for the process of retrieval by category. Functional magnetic resonance imaging combined with a category fluency task may provide a new method to study patients with early Alzheimer's disease.

Adult↗
PubMed1999

Type-2 diabetes and cognitive function in a non-demented population.

OBJECTIVES: To study if type-2 (non-insulin-dependent) diabetes mellitus (NIDDM) is associated with cognitive dysfunction independently of clinically diagnosed dementia in an elderly population. MATERIAL AND METHODS: Cognitive function was investigated with a brief neuropsychological test battery in a non-demented elderly population consisting of 183 NIDDM (World Health Organization, 1985) patients and 732 non-diabetic subjects. RESULTS: Patients with NIDDM were impaired in the Trail-Making Test parts A and C, which may be a reflection of mildly affected frontal lobe/executive functions. Women with NIDDM performed better than non-diabetic subjects in the Mini-Mental State Examination. CONCLUSIONS: We conclude that NIDDM per se is not associated with impaired memory in the elderly, and the minor defects observed in tests of frontal lobe/executive functions are unlikely to affect daily living. In the non-demented population aged 69 78 years, NIDDM does not carry a significant risk of cognitive dysfunction, when compared to the non-diabetic subjects.

Activities of Daily Living↗
PubMed1998

Cognitive function in an elderly population with persistent impaired glucose tolerance.

OBJECTIVE: To study cognitive function in an elderly population with persistent impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS: Fasting and postload 2-h plasma glucose and insulin levels were determined at baseline in a population-based sample of 1,300 people and repeated an average of 3.5 years later in 980 subjects. At follow-up, cognitive function was evaluated in subjects with persistent normal glucose tolerance (NGT; n = 506) and IGT (n = 80) with a brief neuropsychological test battery. RESULTS: Subjects with persistent IGT scored lower in the Mini-Mental State Examination (MMSE) and in the Buschke Selective Reminding Test long-term memory scores. Multiple linear regression analysis revealed that age, education, and insulin levels (either fasting or 2-h value) were associated with the MMSE score in subjects with persistent IGT. Other potential risk factors for impaired cognitive function were not significantly associated with the MMSE score. CONCLUSIONS: Our study showed that persistent IGT in the elderly is associated with mildly impaired cognitive function, and hyperinsulinemia may account for this association.

Age Factors↗
PubMed1997

Association between features of the insulin resistance syndrome and Alzheimer's disease independently of apolipoprotein E4 phenotype: cross sectional population based study.

OBJECTIVE: To determine the association between features of the insulin resistance syndrome and Alzheimer's disease. DESIGN: Cross sectional population based study. SUBJECTS: 980 people aged 69 to 78 (349 men, 631 women). SETTING: Population of Kuopio, eastern Finland. MAIN OUTCOME MEASURES: Presence of features of the insulin resistance syndrome and diagnosis of Alzheimer's disease by detailed neurological and neuropsychological evaluation. RESULTS: 46 (4.7%) subjects were classified as having probable or possible Alzheimer's disease. In univariate analyses, apolipoprotein E4 phenotype (odds ratio; 95% confidence interval 3.24: 1.77 to 5.92), age (1.16; 1.05 to 1.29), low level of education (0.82; 0.72 to 0.93), low total cholesterol concentration (0.77; 0.59 to 1.00), high systolic blood pressure (1.01; 1.00 to 1.03), high fasting and 2 hour plasma glucose concentrations (1.11; 1.01 to 1.23 and 1.08; 1.03 to 1.13, respectively), high fasting and 2 hour insulin concentrations (1.05; 1.02 to 1.08 and 1.003; 1.00 to 1.01, respectively), and abnormal glucose tolerance (1.86; 1.23 to 2.80) were significantly associated with Alzheimer's disease. In multivariate analysis including apolipoprotein E4 phenotype, age, education, systolic blood pressure, total cholesterol concentration, fasting glucose concentration, and insulin concentration, apolipoprotein E4 phenotype, age, education, total cholesterol, and insulin were significantly associated with Alzheimer's disease. In 532 non-diabetic subjects without the e4 allele hyperinsulinaemia was associated with an increased risk for Alzheimer's disease (prevalence of disease 7.5% v 1.4% in normoinsulinaemic subjects, P = 0.0004). In contrast, in the 228 with the e4 allele hyperinsulinaemia had no effect on the risk of disease (7.0% v 7.1%, respectively). CONCLUSION: Features of the insulin resistance syndrome are associated with Alzheimer's disease independently of apolipoprotein E4 phenotype.

Aged↗
PubMed1997

Fragile-X: neuropsychological test performance, CGG triplet repeat lengths, and hippocampal volumes.

We compared cognitive performance and hippocampal volumes using magnetic resonance imaging (MRI) in adult fragile-X [fra(X)] males and females with either premutation (pM) or full mutation (fM) (n = 10 in all groups). Cognitive performance of fM males in the Wechsler Adult Intelligence Scale-Revised was worse than that of pM males, and the deficits in fM females were qualitatively similar, but less severe. In a visual memory test, both fM groups were impaired. In a list learning test, fM males were impaired in the learning phase and in delayed recognition. In a logical memory test, fM males and females were not significantly different from pM subjects. Hippocampal volumes normalized for intracranial or brain area did not significantly differ between fM and pM groups. However, positive correlations between left normalized hippocampal volumes and performance in many delayed memory tests observed in pM subjects were absent in fM subjects. Furthermore, in > 50% of the fM subjects, nonspecific changes, such as enlargement of ventricles and perivascular spaces, focal hyperintensities in temporal pole white matter, and/or subjectively assessed atypical appearance of hippocampal morphology, were observed in MRI. The data suggest minor abnormalities in temporal lobe structures in adult fra(X) subjects with fM.

Adult↗
PubMed1997

Decline of frontal lobe functions in subjects with age-associated memory impairment.

OBJECTIVE: To assess frontal lobe functions of subjects with age-associated memory impairment (AAMI) and to examine whether performance on neuropsychological tests is correlated with the volume of the frontal lobes in magnetic resonance imaging. DESIGN: Cross-sectional two-group comparison. SETTING: The Memory Research Clinic of Kuopio University and the Magnetic Resonance Imaging Center of Kuopio University Hospital. PARTICIPANTS: Ninety subjects (mean age, 70.5 years), 43 with AAMI diagnosed according to National Institute of Mental Health criteria and 47 age-matched healthy controls. MEASUREMENTS: Four neuropsychological tests were used to assess frontal lobe function: Verbal Fluency Test (VFT), Modified Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT), and Stroop Test (ST). A 1.5-T magnetic resonance imager was used for volume measurements. RESULTS: The AAMI subjects scored significantly worse on the WCST, ST, and TMT compared with controls (ANCOVA, adjusted for age and education, p < 0.05). The frontal lobe volumes did not differ between AAMI subjects and controls. CONCLUSIONS: AAMI subjects appear to be impaired not only in tests assessing memory but also in tests of executive functions. This finding agrees with previous reports suggesting a central role for frontal dysfunction in memory loss of elderly people.

Aged↗
PubMed1997

Age-associated memory impairment. Normal aging or warning of dementia?

Aging causes deterioration in various aspects of memory performance in healthy adults. Different diagnostic classifications have been proposed for use in the characterisation of mild cognitive disorders associated with aging. One of the best established of these classifications is age-associated memory impairment (AAMI). Epidemiological data suggest that AAMI is a phenomenon of normal aging rather than a sign of progression from normal aging to a pathological state such as Alzheimer's disease. A number of studies that have combined neuropsychological, neuroradiological and neurophysiological data have provided evidence of distinct characteristics in individuals with AAMI. At present, however, AAMI does not appear to describe any homogeneous group of individuals. Moreover, the neuropsychological methods used to diagnose AAMI appear to be ambiguous. Thus, AAMI appears to occur in a highly heterogeneous group of individuals, and is of questionable clinical or theoretical significance. More reliable diagnostic approaches are needed for use in studies that are attempting to identify the risk factors for dementia or to find a treatment for very early dementia.

Aged↗
PubMed1996

Slow-wave activity in the spectral analysis of the electroencephalogram and volumes of hippocampus in subgroups of Alzheimer's disease patients.

This study examined patients who fulfilled the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association Work Group criteria for probable Alzheimer's disease (AD; n = 35) and controls for magnetic resonance imaging and psychometric data (n = 16) and for quantitative electroencephalogram data (n = 34). A cluster analysis performed on neuropsychological variables identified 2 AD subgroups: The AD1 group (n = 12) had impaired memory and executive functions but preserved verbal and visuospatial functions. The AD2 group (n = 23) had global impairment. The AD2 group had higher theta amplitude in the temporo-occipital, centroparietal, and frontal derivation and lower peak and mean frequency than the AD1 group or controls. Both AD groups had more severe memory deficits and clearly smaller hippocampal volumes than controls. This may implicate that the degree of damage in ascending activating systems differs in these subgroups, although the damage in the hippocampus is equal.

Aged↗
PubMed1996

Clinical and neuropsychological characteristics in familial and sporadic Alzheimer's disease: relation to apolipoprotein E polymorphism.

Alzheimer's disease (AD) is a heterogeneous entity presenting as sporadic and familial disease. In familial AD, there is evidence for genetic linkage to a yet undefined gene on chromosome 14 in early-onset pedigrees and on chromosome 19 in late-onset pedigrees. In a few early-onset kindreds, there were mutations in the amyloid precursor gene on chromosome 21. There is an increased frequency of apolipoprotein E (ApoE) epsilon4 allele in patients with late-onset AD. We studied the clinical presentation and profile of cognitive deficits in 58 AD patients at the early stage of the disease. We divided the AD patients into subgroups of sporadic late-onset (SLO) (> or = 65 years), familial late-onset (FLO) (> or = 65 years), sporadic early-onset (SEO) (<65 years), and familial early-onset (FEO) (<65 years) patients and into three subgroups according to their ApoE genotype zero epsilon4, one epsilon4, and two epsilon4 alleles. The AD subgroups did not differ in the global clinical severity of dementia or the duration of the disease. SLO, FLO, SEO, and FEO subgroups did not differ in clinical characteristics such as occurrence of rigidity, hypokinesia, tremor, myoclonus, hallucinations, delusions, or epileptic seizures nor in the profile of deficits on tests assessing memory, language, visuospatial, executive, and praxic functions. The epsilon4++ allele frequency was 0.43 for all AD patients and did not differ across subgroups divided according to the familial aggregation and age of onset. Patients with two epsilon4 alleles had earlier age at onset of dementia than those with no epsilon4 allele (63 +/- 9 versus 68 +/- 9 years), but otherwise the clinical symptoms and signs were not related to the ApoE genotype. However, the AD patients with two epsilon 4 alleles had lowest scores on memory tests and differed significantly from those with one or zero epsilon4 allele in the delayed list learning (p<0.05) and from those with zero epsilon4 allele in the immediate and delayed story recall. In contrast, verbal functions were better preserved in two epsilon4 patients than in those with other ApoE genotypes. This study failed to confirm the earlier reports of severe aphasia, agnosia, and apraxia in familial AD patients, but the clinical phenotype was similar irrespective to the familial aggregation. However, AD patients with two epsilon4 alleles are characterized by more severe memory loss and earlier age of onset than those without the epsilon4 allele.

Age of Onset↗