Significant Predictors Of Dementia Research Articles

Risk factors for dementia in Parkinson's disease: effect of education.

Cognitive deficits are common in Parkinson's disease (PD), but the pathophysiology and relationship to Alzheimer's disease (AD) are not understood. We used a case-control format to investigate putative risk factors for the development of dementia in patients with Parkinson's disease. We compared 52 cognitively intact patients with PD to 43 PD patients with dementia with regard to factors previously suggested as relevant to either AD or PD. Multiple logistic regression yielded the following significant predictors of dementia in PD: lack of education (less than a high school graduate) (OR 21); severity of motor deficit (UPDRS total motor score greater than 20; OR 6.34), and PD onset at greater than 60 years of age (OR 4.12). The predictive probability of dementia in our subjects when all three variables were positive was 97.9%. We conclude that education may modify the risk of cognitive decline in PD. Protective effects of educational attainment, independent of dementia etiology, may be due to greater functional brain reserve.

Cognitive impairment and mortality in older community residents.

Cognitive impairment among the elderly has been linked to mortality in studies of clinical populations. The purpose of this study was to examine the mortality risk associated with cognitive impairment among elderly populations in the community. Cognitive impairment and other social and health factors were assessed in 1855 elderly community residents. This sample was reinterviewed periodically to assess changes in health and survival. At baseline 33% of the sample were mildly impaired and 8% were severely impaired. Across a 48-month observation period the survival probability was .85 for the cognitively unimpaired, .69 for the mildly impaired, and .51 for severely impaired respondents. When adjustments were made for the effects of other health and social covariates, severely impaired persons were twice as likely to die as unimpaired persons. Those who were mildly impaired were also at an increased risk. Other investigators have found that cognitive impairment is a significant predictor of dementia. We found that it is a significant predictor of mortality as well. Early detection of impaired cognition and attention to associated health problems could improve the quality of life of these older adults and perhaps extend their survival.

Subtle extrapyramidal signs can predict the development of dementia in elderly individuals.

To assess the significance of mild extrapyramidal signs (EPSs) in aging, we prospectively followed 228 elderly individuals without dementia or major neurologic disease at baseline. Seventy-three (32%) showed mild idiopathic EPSs at baseline assessment and 32 (14%) of these 228 individuals met NINCDS-ADRDA criteria for probable or possible Alzheimer's disease on follow-up. While none of these individuals developed Parkinson's disease, those with more than one EPS at baseline were significantly more likely to become demented during follow-up than were those with one or no EPS, an association not confounded by age, education, or gender. Individuals with more than one EPS and with cognitive impairment (CI) at baseline were at highest risk for dementia. EPSs were also independently associated with incident dementia in the absence of CI at baseline. We conclude that mild EPSs are a significant predictor of dementia in elderly individuals.

Dementia in AIDS patients: incidence and risk factors. Multicenter AIDS Cohort Study.

We determined incidence and future projections of dementia after AIDS onset in 492 homosexual men with AIDS in the Baltimore/Los Angeles sites of the Multicenter AIDS Cohort Study, 64 of whom developed dementia. We studied various risk factors for dementia, including demographic and clinical features, medical history, markers of immune status before AIDS, and zidovudine use. During the first 2 years after AIDS, HIV dementia developed at an annual rate of 7%. Overall, 15% of the cohort followed through death developed dementia. The median survival after dementia was 6.0 months. Using a proportional hazards model, risk factors for more rapid development of dementia were lower hemoglobin (relative hazard, 0.59 per additional 2 g/dl; p = 0.0005) and body mass index (relative hazard, 0.64 per additional 5 kg/m2; p = 0.05) 1 to 6 months before AIDS, more constitutional symptoms 7 to 12 months before AIDS (relative hazard, 1.68 per additional symptom, p = 0.005), and older age at AIDS onset (relative hazard, 1.60 per decade older; p = 0.009). In a multivariate model, pre-AIDS hemoglobin remained the most significant predictor of dementia. There were no significant risks defined from demographic characteristics, specific AIDS-defining illnesses, zidovudine use before AIDS, or CD4+ lymphocyte count before AIDS. We project that 12 months after the first AIDS diagnosis, 7.1% of survivors will have dementia. The observed association between anemia, low weight, constitutional symptoms, and dementia suggests a role for cytokines inducing both systemic and neurologic disease.