The biology of Alzheimer's disease.

The pathological hallmarks of Alzheimer's disease (AD) are amyloid angiopathy (AA), neutritic plaques (NP), and neurofibrillary tangles (NFT). This article will provide an update on Alzheimer's disease as well as discuss the key elements of a proposed multi-step pathogenic pathway. In an attempt to simplify this complex process, the focus will be on the production of NP/AA and NFT and the mechanisms of disease underlying their formation. In particular, this review will explore the possibility that AD is in part an inflammatory or immunological process, the potential role of oxidative DNA damage from oxygen free radical metabolites, and/or the putative role of excitotoxicity or ischemic neurological injury. Several genes have been identified as causative of AD and the evidence supports multiple mechanisms of disease. Alzheimer's disease may represent a final common pathway of different disease processes.

Medication management capacity in highly functioning community-living older adults: detection of early deficits.

OBJECTIVE: The Drug Regimen Unassisted Grading Scale (DRUGS) was developed and employed in testing the hypothesis that the inability to take medication independently may correlate with the presence of cognitive impairment. DESIGN: Cross-sectional study. SETTING: Two continuing care retirement facilities in the Greater Boston area. PARTICIPANTS: The study population included outpatients > or = 70 years old. MEASUREMENTS: We developed a novel performance-based measure, the DRUGS tool, involving a step-wise progression of four tasks: (1) identification; (2) access; (3) dosage; and (4) timing. RESULTS: Fifty-nine participants aged 84.2 +/- 5.1 years (mean +/- SD) completed the study. The DRUGS tool score was inversely related to age (r = -.41, P = .001). Compared with independent-living, residence in assisted-living was associated with lower DRUGS tool scores (82.0% vs 93.8%, P = .009). The DRUGS tool score was associated with self-reported Medication Management capacity (94.8% able vs 86.2% unable to take medications independently by self-report, P = .047). Both DRUGS tool score and self-reported Medication Management capacity were associated with MMSE (P = .0008 and P = .044, respectively). The multivariate model, with DRUGS tool Summary Score as the dependent variable, adjusted for age and sex, included MMSE (P = .023) and self-reported IADL (P = .038). CONCLUSION: There is an association between performance on the DRUGS tool and level of cognitive function. The DRUGS tool represents a unique individualized, yet standardized, assessment of the ability to function independently for ambulatory older persons. It may be useful for identifying those highly functioning older persons, at an early phase of cognitive decline, in whom targeted intervention would likely be most effective and efficient.

Physician perceptions of HMO care for older persons. Health Maintenance Organization.

OBJECTIVE: Physician attitudes may be a key factor in effective managed care for older patients. We sought to explore physicians' views of the influence of health maintenance organization (HMO) policies on the care of their older patients. DESIGN: A self-administered one-page questionnaire consisting of questions about physician demographics, the impact of HMOs on physician practice, patient care, HMO policies, and respondents' personal use of managed health care plans. PARTICIPANTS: The survey was mailed to 838 randomly selected primary care physicians affiliated with two large, nonprofit, academically-oriented, Medicare HMOs in Massachusetts. RESULTS: Completed surveys were received from 516 of 797 eligible primary care physicians, affiliated with either Secure Horizons (Tufts Associated Health Plan) or First Seniority (Harvard Pilgrim Health Care). About half (55%) of the physician respondents reported they had sufficient time to spend with their older patients. Most (81%) respondents indicated that overall, patients aged 65 and older received either better care or no change in care after joining an HMO. The majority of physicians reported that HMO affiliation had increased the frequency with which they addressed geriatric issues with their older patients. There were several patterns of response that emerged with respect to beliefs about key HMO policies. CONCLUSIONS: The majority of physicians working in two nonprofit, academically oriented Medicare HMOs in Massachusetts believed that the overall quality of care that older patients received after joining an HMO either did not change or improved.

One-year follow-up of medication management capacity in highly functioning older adults.

BACKGROUND: We tested the hypothesis that impairment in the ability to take medication independently predicts early functional decline. METHODS: A 12-month, prospective cohort study was performed at two continuing-care retirement facilities using the Drug Regimen Unassisted Grading Scale (DRUGS). This geriatric screening tool utilizes a stepwise progression of four tasks: (i) identification, (ii) access. (iii) dosage, and (iv) timing. RESULTS: Forty-seven (86%) of the eligible participants completed the 12-month follow-up assessment; three were transferred to skilled nursing facilities. The mean age at study entry was 84.2+/-5.1 years; 72% of the participants were women, and 68% were college educated. At 12 months there was a decline in the Mini-Mental State Examination (MMSE) score (p = .029), an increase in the timed "Up and Go" test (p = .023), and a decline in the DRUGS score (p .029). Nine (18%) of the participants resided in assisted- versus independent-living situations compared with three participants (5%) at study entry (p = .031). Both 12-month DRUGS score and 12-month self-reported medication management capacity were associated with 12-month MMSE (p = .0001 and p = .019, respectively). Baseline DRUGS score was associated with 12-month MMSE and Geriatric Depression Scale scores (p = .0002 and p = .002, respectively). Both baseline DRUGS score and self-reported medication management capacity were also associated with residence in assisted-living communities at 6 months (p = .029 and p = .040, respectively). MMSE was not associated with any of the clinical outcomes.

Falls and function. How to prevent falls and injuries in patients with impaired mobility.

Older persons, particularly those with compromised health, are at increased risk of falls, and these events can significantly affect a person's quality of life. Risk factors include age, neurologic and musculoskeletal conditions, decreased physical strength, foot disorders, and use of medications or alcohol. When evaluating a patient who has fallen, physicians should be on the alert for intrinsic pathologies or situational conditions that place an older patient at increased risk for these incidents. Physical examination should include consideration of postural vital signs, polypharmacy, and sensory decline. Performance assessments are excellent tools for observing the status of gait and balance. Proper documentation and evaluation of a fall is a key step in preventive management.

Notation of previous falls in admission record of hospitalized elderly.

To test the hypothesis that a history of falling is underreported by physicians and nurses, we assessed the extent to which previous falls are noted in the admission medical history. A total of 168 community-dwelling and institutionalized elderly adults, > or = 70 years old, were evaluated in the emergency ward of a tertiary care community-based teaching hospital, and admitted to a general medical ward. Physicians' and nurses' emergency ward and admission notes were reviewed for the inclusion of "falls." Within 72 hours of admission, the information provided or omitted in the medical record was confirmed or refuted by face-to-face interview. Follow-up data were gleaned from computer-based records. The sample population consisted of 113 patients, 56% female, with a mean age of 80.7. Seventy-six patients had fallen within the past 10 years: of these, 32 (42%) were Recent Fallers, and 44 (58%) were Multiple Fallers. Review of the medical records revealed that 56 (74%) of the 76 Fallers were not noted to have fallen by the medical staff. Moreover, 15 (47%) of the Recent Fallers and 28 (64%) of the Multiple Fallers were missed. Examination of the nursing notes yielded similar results. In conclusion, elderly patients fall more frequently than recognized. Physicians and/or nurses should include a question regarding falls as part of the routine medical history.

Gait variability and fall risk in community-living older adults: a 1-year prospective study.

OBJECTIVE: To test the hypothesis that increased gait variability predicts falls among community-living older adults attending an outpatient clinic. DESIGN: Prospective, cohort study. SETTING: Three outpatient geriatric clinics. PARTICIPANTS: Fifty-two community-living, ambulatory men and women aged > or = 70 years. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Subjects walked at a normal pace for up to 6 minutes wearing force-sensitive insoles that measured the gait rhythm on a stride-to-stride basis. Afterward, subjects reported fall status on a weekly basis for 1 year. The primary outcomes were the association between measures of the stride-to-stride fluctuations in gait rhythm and (1) subsequent falls during a 12-month follow-up period and (2) potential contributing factors. RESULTS: Almost 40% of the subjects reported falling during the 12-month follow-up period. Stride time variability was 106 +/- 30 ms in subjects who subsequently fell (n = 20) and 49 +/- 4 ms in those who did not experience a fall (n = 32) during the 12-month follow-up period (p <.04). Logistic regression also showed that stride time variability predicted falls (p <.05). Stride time variability correlated significantly with multiple factors including strength, balance, gait speed, functional status, and even mental health, but these other measures did not discriminate future fallers from nonfallers. CONCLUSIONS: These findings show both the feasibility of obtaining stride-to-stride measures of gait timing in the ambulatory setting and the potential use of gait variability measures in augmenting the prospective evaluation of fall risk in community-living older adults.

Increased gait unsteadiness in community-dwelling elderly fallers.

OBJECTIVE: To test the hypothesis that quantitative measures of gait unsteadiness are increased in community-dwelling elderly fallers. STUDY DESIGN: Retrospective, case-control study. SETTING: General community. PARTICIPANTS: Thirty-five community-dwelling elderly subjects older than 70 years of age who were capable of ambulating independently for 6 minutes were categorized as fallers (age, 82.2 +/- 4.9 yrs [mean +/- SD]; n = 18) and nonfallers (age, 76.5 +/- 4.0 yrs; n = 17) based on history; 22 young (age, 24.6 +/- 1.9 yrs), healthy subjects also participated as a second reference group. MAIN OUTCOME MEASURES: Stride-to-stride variability (standard deviation and coefficient of variation) of stride time, stance time, swing time, and percent stance time measured during a 6-minute walk. RESULTS: All measures of gait variability were significantly greater in the elderly fallers compared with both the elderly nonfallers and the young subjects (p < .0002). In contrast, walking speed of the elderly fallers was similar to that of the nonfallers. There were little or no differences in the variability measures of the elderly nonfallers compared with the young subjects. CONCLUSIONS: Stride-to-stride temporal variations of gait are relatively unchanged in community-dwelling elderly nonfallers, but are significantly increased in elderly fallers. Quantitative measurement of gait unsteadiness may be useful in assessing fall risk in the elderly.