CONTEXT In spite of numerous studies on the occurrence of dementia, many questions remain, such as the relation between age, aging, and dementing disorders. This question is relevant both for ...understanding the pathogenetic mechanism of the dementias and for the public health prospective because of the increasing number of 85-year-old or older persons in our population. OBJECTIVE To estimate the occurrence of dementia in the very old, including nonagenarians, in relation to age, gender, and different dementia types. DESIGN An epidemiological survey where all participants were clinically examined by physicians, assessed by psychologists, and interviewed by nurses. The Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R) criteria for dementia were followed. A category of "questionable dementia" was added when all criteria were not fulfilled. A double diagnostic procedure was used for all subjects. SETTING Community-based population, including all inhabitants of 2 areas in central Stockholm, Sweden (N=1848). PARTICIPANTS Of the 1848 subjects in the study population, 168 (9.1%) had died and 56 (3%) moved before examination. Of the remaining subjects, 1424 (87.7%) were examined, and the refusal rate was 12.3%. MAIN OUTCOME MEASURES Age- and gender-specific prevalence figures, and gender- and education-adjusted odds ratios were used. RESULTS At the end of the diagnostic procedure, 358 clinically definite cases of dementia and 101 questionable cases of dementia were identified. Alzheimer disease (AD) contributed to 76.5%, and vascular dementia (VaD) to 17.9%. The prevalence of dementia increases from 13% in the 77- to 84-year-old subjects to 48% among persons 95 years and older (from 18% to 61% when questionable cases were included). The odds ratio for subjects 90 to 94 years and 95 years and older in comparison with 77- to 84-year-old subjects was 3.7 (95% confidence interval CI, 2.7-5.1) and 6.5 (95% CI, 3.9-10.8) for dementia, 4.8 (95% CI, 3.3-7.0) and 8.0 (95% CI, 4.6-14.0) for persons with AD, 2.3 (95% CI, 1.3-4.2) and 4.6 (95% CI, 1.9-11.2) for VaD, respectively. CONCLUSIONS Dementia prevalence continues to increase even in the most advanced ages. This increase is especially evident among women and is more clear for AD. We believe that our prevalence data reflect the differential distribution of dementia risk.Arch Neurol. 1999;56:587-592-->
Variability in occurrence estimates is one of the basic features of the epidemiology of dementia and mild cognitive impairment (MCI). This review will cover two levels of variability that affect ...epidemiological research on dementia and MCI: the conceptual and the operational level. More specifically, it is highlighted how the lack of a precise definition of MCI leads to a greater variability in the occurrence estimates of this condition, when compared to dementia. Variability will decrease only when more precise criteria and aims of the concept "MCI" will be specified.
OBJECTIVE To examine whether antihypertensive medication use can affect the occurrence and progression of dementia. SUBJECTS AND METHODS In a community cohort of 1810 persons aged 75 years and older, ...225 prevalent cases of dementia were detected. Among the 1301 persons without dementia, 224 incident cases of dementia were identified during an average period of 3 years. Among the 225 prevalent cases of dementia, 79 were suitable for the analysis of cognitive decline. Information on drug use was collected for the 2 weeks preceding the baseline interview. RESULTS Subjects taking antihypertensive medication (n=651, 83.9% of whom took diuretics) had a lower prevalence of dementia than those not taking antihypertensive medication (P<.001). Subjects without dementia who were taking antihypertensive medication at baseline (n=584) had a reduced incidence of dementia (adjusted relative risk, 0.7; 95% confidence interval, 0.6-1.0; P=.03). Furthermore, subjects taking diuretics (n=484) had an adjusted relative risk of 0.7 (95% confidence interval, 0.5-1.0; P=.02) for all dementia, and subjects taking diuretic monotherapy (n=345) had an adjusted relative risk of 0.6 (95% confidence interval, 0.4-0.9; P=.006). The use of other antihypertensive medication (calcium antagonists or β-blockers), however, was related to a reduced risk of Alzheimer disease (adjusted relative risk, 0.6; 95% confidence interval, 0.3-1.2) only in the subpopulation with a higher baseline blood pressure (n=458). Patients with dementia at baseline who were not taking diuretics had a 2-fold faster rate of decline in the score on the Mini-Mental State Examination than those taking diuretics. CONCLUSION The use of diuretics may protect against dementia in elderly persons.Arch Neurol. 1999;56:991-996-->
Vascular dementia, the second most common dementia after Alzheimer disease, has great potential for prevention and treatment. Epidemiological data provide the basis for planning primary prevention ...and clinical trials. Nevertheless, general consensus on disease definition and diagnostic criteria are still not well defined. Despite these limitations, some results from the Kungsholmen project, an epidemiological longitudinal study of people 75 years and older, are presented here.
The aim of this article was to assess the attitudes of older adults (age >74 years) toward research participation. A questionnaire was mailed to the study population (
n = 1197) which included people ...who had participated in a longitudinal study once, twice, three times, or more. The participants showed a positive attitude in general as 79% saw an advantage of participation and 72% did not report any negative reaction. Older elderly with impaired cognitive functioning and lower education showed the least positive attitude, reporting the first contact and the cognitive testing as the most stressful situations. The group who had participated more than once was the most positive, but more often refused some parts of the clinical examination. We conclude that: (1) more attention is necessary to the initial contact; (2) reduction of stressful or tiring examinations is recommended; and (3) complete information about the research, including the right to refuse individual parts of the study, must be given. Such procedures will improve both the quality and the ethics of the research.
The aim of our study was to define the diagnostic importance of a complete electronystagmographic (ENG) examination (visual-vestibular, vestibular and visual suppression tests on caloric nystagmus) ...in patients affected by MS. Of 144 patients examined, 116 were definite and 28 possible. Descriptive data of the instrumental findings showed very frequent alterations of one or more subtests: pursuit movements and visual suppression test were especially pathological, in respectively 56% and 58% of the cases; spontaneous and/or evoked nystagmus was present in 45%. A comparison between clinical and instrumental evidence of brainstem/cerebellar involvement indicated that 18% of the definite and 32% of the possible MS cases presented a negative clinical examination with positive instrumental findings. The usefulness of including a comprehensive ENG examination to obtain paraclinical evidence of a second lesion in the CNS in early MS is discussed.
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