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Radiotherapy has been reported to cause neuropsychological dysfunction. Here we examined whether exposure to atomic bomb radiation affected the incidence of dementia among 2286 atomic bomb survivors and controls - all members of the Adult Health Study cohort. Study subjects were non-demented and aged >or=60 years at baseline examination and had been exposed in 1945 at >or=13 years of age to a relatively low dose (or=500 mGy group. Alzheimer disease was the predominant type of dementia in each dose category. After adjustment for potential risk factors, radiation exposure did not affect the incidence rate of either all dementia or any of its subtypes. No case of dementia had a history of therapeutic cranial irradiation. Although we found no relationship between radiation exposure and the development of dementia among atomic bomb survivors exposed at >or=13 years old in this longitudinal study, effects on increased risk of early death among atomic bomb survivors will be considered.

Background: Although dementia is rarely listed on death certificates, it does contribute to mortality. The predominant immediate causes of death coincident with dementia are pneumonia and cardiovascular diseases., Objective: To estimate the impact of dementia on specific mortality risks., Methods: We applied DSM-III/R criteria for Alzheimer's disease (AD) and vascular dementia (VaD) to 2,172 subjects of the Adult Health Study of the Radiation Effects Research Foundation who were 60 or more years old when examined from 1992 to 1996. The underlying causes of death were compiled from death certificates. We performed a Poisson regression analysis to evaluate specific causes of mortality for which AD or VaD was a significant risk factor., Results: The relative risk of mortality was 2.2 for AD and 2.4 for VaD. Mortality from pneumonia and stroke was elevated for both types of dementia, independent of other medical conditions. AD was also associated with death from trauma., Conclusion: Dementia was a predictor of death due to pneumonia, stroke, and trauma among the Japanese elderly. The prevention and early detection of those conditions are important in the medical care and treatment of dementia cases., (Copyright 2004 S. Karger AG, Basel)

Objectives: To investigate the association between midlife risk factors and the development of vascular dementia (VaD) or Alzheimer's disease (AD) 25 to 30 years later., Design: A prevalence study within a longitudinal cohort study., Setting: Subjects in the Adult Health Study (a prospective cohort study begun in 1958) have been followed through biennial medical examinations in Hiroshima, Japan., Participants: One thousand seven hundred seventy-four subjects in Hiroshima, Japan born before September 1932 (1,660 with no dementia, 114 with dementia (51 with AD, and 38 with VaD) diagnosed from 1992 to 1997 according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria)., Measurements: The subjects were examined for effect on dementia of sex, age, education, atomic bomb radiation dose, and midlife factors associated with risk (smoking, alcohol intake, physical activity, dietary habits, systolic blood pressure (SBP), body mass index, and history of diabetes mellitus) that had been evaluated in 1965-1970., Results: VaD prevalence increased significantly with age, higher SBP, and lower milk intake. The odds ratios of VaD for age (in 5-year increments), SBP (10 mmHg increments), and milk intake (almost daily/less than four times a week) were 1.29, 1.33, and 0.35, respectively. The risk factors for VaD were compatible with the risk factors for stroke in this study population. AD prevalence increased significantly with age and lower education. Other midlife factors and radiation dose did not show any significant association with VaD or AD., Conclusion: Increased SBP and low milk intake in midlife were associated with VaD detected 25 to 30 years later. Early behavioral control of the risk factors for vascular disease might reduce the risk of dementia.

Background: Prospective studies have shown that cognitive impairment is a strong and consistent risk factor of physical disability. However, cognitive impairment has been based on the result of a single screening tool., Objective: To investigate the role of cognition in the subsequent incidence and decline of functional disability in basic activities of daily living (ADL) and instrumental activities of daily living (IADL) after a full assessment of dementia., Methods: A group of 1,358 Japanese atomic bomb survivors aged 61 years or older who lived in the community or in institutions in Hiroshima City were followed for 4 years. During the baseline survey (1993-1995), subjects were administered a screening test for cognitive impairment. Those suspected of dementia underwent a series of cognitive tests (Hasegawa's dementia scale, Clinical Dementia Rating) and a neurological examination. The diagnosis of dementia was made according to DSM-III-R criteria. Study subjects were questioned about their reported ADL and their IADL. During the follow-up period, deaths were recorded and a follow-up survey (1997-1999) used to assess ADL and IADL performance., Results: Dementia, even after adjustment for age, sex and history of stroke, was a strong predictor of functional disability, as indicated by ADL (odds ratio, OR = 14.0; confidence interval, CI = 5.4-36.3), IADL (OR = 10.1, CI = 2.2-46.4), and also by assessment of decline in ADL (OR = 9.8, CI = 4.2-22.8) or IADL status (OR = 3.9, CI = 1.8-8.3)., Conclusion: Dementia is an important determinant of functional status. Deterioration in ADL is more significant than deterioration in IADL, suggesting that factors other than cognition, such as motivation or perceptual, sensory and motor abilities, may be important in IADL performance. This study confirms previous findings on risk factors that affect functional ability and extends our knowledge by examining several criteria of function that are important in the daily lives of elderly people., (Copyright 2002 S. Karger AG, Basel)

The Cognitive Abilities Screening Instrument (CASI) was developed by Japanese and American researchers, including the authors, to examine cognitive functions, based on previous neuropsychological tests, such as Hasegawa's Dementia Scale and the MMSE. From the Adult Health Study (AHS) population of the Radiation Effects Research Foundation, 2052 men and women aged 60 or over and living in Hiroshima were evaluated for their cognitive functions using the CASI. Dementia was diagnosed in 93 and 1,959 were considered not to suffer from dementia based on the DSM-III-R criteria using neurological examination and the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) completed by caregivers. Multivariate regression analysis not only indicated that total score was higher with lower age and higher education but that the slope of its decrease is steeper with higher age and fewer years of education. The slope of score decrease with increase of age was steeper for women than for men. Furthermore, CASI items were categorized by domains of cognitive function. Multivariate regression analysis for each cognitive domain showed clear effects of age and level of education. The effect of age for the nondementia subjects was large in cognitive domains dealing with temporal orientation, short-term memory, and list-generating fluency. The most useful cognitive domains for diagnosing dementia were temporal orientation, short-term memory, and list-generating fluency, as was indicated by high sensitivity and specificity.

Background: Clinical investigators from Seattle, Honolulu, Tokyo, and Hiroshima participated in two standardization exercises in which data were collected on independent assessments. Exercises were conducted to evaluate the interobserver agreement on clinical diagnoses of dementia and dementia subtypes in a cross-national study of dementia prevalence and incidence rates in the United States and Japan., Method: Fifteen clinicians from four participating sites assessed the diagnosis of 85 patients based on standardized summaries of clinical and diagnostic test data on each patient. Diagnostic guidelines and conventions were adopted on the basis of group consensus during standardization exercises., Results: Using DSM-III-R criteria, generally good levels of agreement for all dementia diagnostic categories occurred in both years. For most measures of diagnostic agreement, improvements were observed between the 1995 and 1996 standardization sessions. Interrater agreement was highest for discrimination between dementia and nondementia (1996 overall kappa, K = .90). The kappa values for dementia subtypes in 1996 ranged from .5 to .85, and for all sites combined the value was .67. For dementia subtypes, percent agreement was highest for vascular dementia and Alzheimer's disease, but was less reliable for other types of dementia., Conclusions: Clinicians from different cultures and medical traditions can reliably use the DSM-III-R criteria to classify dementia cases in cross-national research. The interrater agreement on dementia and its subtypes improved after clear-cut guidelines for interpretation of diagnostic criteria were developed and followed.

The patient was a 48-year-old woman with gait disturbance as her initial symptom. Two years after the onset of the gait disturbance, she developed motor weakness and a sensory disturbance in her limbs, and dementia. On admission to our hospital, the patient's serum vitamin B12 and folic acid levels were low, and she was found to have normochromic anemia. She also had widespread coarse hair and canities was diagnosed. The patient's paresthesia resolved in response to injection of 500 micrograms mecobalamin every other day, and the Hasegawa dementia scale score and the patient's hand grip strength improved. Her gait also improved, and she became able to walk on tiptoe. Her hair returned to normal. Supplementation with high-dose methyl B12 appeared to be effective to some extent in treating a broad range of neurologic disorders besides subacute combined degeneration of the spinal cord. In addition, the hair abnormality may be a marker of vitamin B12 deficiency.