Leisure activities and the risk of amnestic mild cognitive impairment in the elderly.

OBJECTIVE: To study the influence of leisure activity participation on risk of development of amnestic mild cognitive impairment (aMCI). METHODS: The authors examined the relationship between baseline level of participation in leisure activities and risk of aMCI in a prospective cohort of 437 community-residing subjects older than 75 years, initially free of dementia or aMCI, using Cox analysis adjusted for age, sex, education, and chronic illnesses. The authors derived Cognitive and Physical Activity Scales based on frequency of participation in individual activities. RESULTS: Over a median follow-up of 5.6 years, 58 subjects had development of aMCI. A one-point increase on the Cognitive (hazard ratio [HR] 0.95, 95% CI 0.91 to 0.99) but not Physical Activities Scale (HR 0.97, 95% CI 0.93 to 1.01) was associated with lower risk of aMCI. Subjects with Cognitive Activity scores in the highest (HR 0.46, 95% CI 0.24 to 0.91) and middle thirds (HR 0.52, 95% CI 0.29 to 0.96) had a lower risk of aMCI compared with subjects in the lowest third. The association persisted even after excluding subjects who converted to dementia within 2 years of meeting criteria for aMCI. CONCLUSIONS: Cognitive activity participation is associated with lower risk of development of amnestic mild cognitive impairment, even after excluding individuals at early stages of dementia.

Low blood pressure and the risk of dementia in very old individuals.

BACKGROUND: The role of blood pressure (BP) as a risk factor for dementia is complex and may be age dependent. In very old individuals, low BP might increase risk for dementia, perhaps by reducing cerebral perfusion pressure. METHODS: The association between BP and dementia was examined in the Bronx Aging Study, a prospective study of 488 community-dwelling elderly individuals over age 75, dementia-free at baseline (1980 to 1983) and followed at 12- to 18-month intervals. Subjects with baseline BP and with at least one follow-up visit were included (n = 406). Incident dementia was diagnosed using the criteria of the Diagnostic and Statistical Manual of Mental Disorders (3rd rev. ed.). RESULTS: Over 21 years (median 6.7 years), 122 subjects developed dementia (65 Alzheimer's disease [AD], 28 vascular dementia, 29 other dementias). Relative risk of dementia increased for each 10-mm Hg decrement in diastolic (hazard ratio [HR] 1.20, 95% CI 1.03 to 1.40) and mean arterial (HR 1.16, 95% CI 1.02 to 1.32) pressure, adjusted for age, sex, and education. Low diastolic BP significantly influenced risk of developing AD but not vascular dementia. Upon examination of groups defined by BP, mildly to moderately raised systolic BP (140 to 179 mm Hg) was associated with reduced risk for AD (HR vs normal systolic BP group 0.55, 95% CI 0.32 to 0.96), whereas low diastolic BP (

Cognitive performance in surgically menopausal women on estrogen.

Estrogen replacement therapy (ERT) may help maintain normal cognitive function. Nondemented surgically menopausal women on ERT (n = 10) enrolled in a longitudinal aging study performed better than age- and education-matched control subjects (n = 25) on selected tests of verbal memory and constructional ability. These results suggest that ERT initiated soon after surgical menopause can have long-term neuroprotective effects in cognitively intact women.

Screening for dementia with the memory impairment screen.

OBJECTIVES: To validate a sensitive and specific screening test for AD and other dementias, assess its reliability and discriminative validity, and present normative data for its use in various applied settings. BACKGROUND: To improve discrimination in screening for AD and dementia, we developed the Memory Impairment Screen (MIS), a 4-minute, four-item, delayed free- and cued-recall test of memory impairment. The MIS uses controlled learning to ensure attention, induce specific semantic processing, and optimize encoding specificity to improve detection of dementia. METHODS: Equivalent forms of the MIS were given at the beginning and end of the testing session to assess alternate forms reliability. Discriminative validity was assessed in a criterion sample of 483 aged individuals, 50 of whom had dementia according to Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) criteria. RESULTS: The MIS had good alternate forms reliability, high construct validity for memory impairment, and good discriminative validity in terms of sensitivity, specificity, and positive predictive value. We present normative data for use in settings with different base rates (prevalences) of AD and dementia. CONCLUSION: The MIS provides efficient, reliable, and valid screening for AD and other dementias.

Diagnosis of early dementia by the Double Memory Test: encoding specificity improves diagnostic sensitivity and specificity.

OBJECTIVE: To compare the Double Memory Test (DMT) with standard memory tests in the diagnosis of early dementia. BACKGROUND: Diagnosis of dementia requires memory impairment, but few memory tests coordinate acquisition and retrieval to optimize encoding specificity for high sensitivity and specificity. The DMT was developed to improve early diagnosis. DESIGN: We compared the discriminative validity of the DMT, Paired Associates (PA), and Logical Memory (LM) memory tests in a nested case-control study of 30 cases of early dementia and 90 controls matched for age, education, and sex. METHODS: The DMT includes memory tests with (CCR) and without (ICR) encoding specificity. Both tests use category cues to elicit retrieval, but CCR optimizes encoding specificity because the same cues are used for acquisition and retrieval. ICR does not because category cues are used only for retrieval. We used conditional logistic regression to estimate diagnostic sensitivity and specificity. RESULTS: The median BIMC of dementia cases was 10, indicating mild dementia. CCR had much higher sensitivity (93%) and specificity (99%) than ICR (53%, 94%), PA (68%, 91%), and LM (48%, 92%). CCR had the greatest advantage in the mildest cases. CONCLUSIONS: CCR has substantially higher sensitivity and specificity for diagnosis of early dementia than memory tests that do not coordinate acquisition and retrieval. Superior discrimination by CCR is due to an encoding specificity deficit in dementia that increases the difference in recall by cases and controls. CCR is an efficient test with excellent discriminative validity that should facilitate diagnosis of early dementia.

Aging, encoding specificity, and memory change in the Double Memory Test.

Aged and young adults were tested by category cued recall after learning with category cues (CCR) or with item cues (ICR). CCR was about twice ICR for both aged and young adults. The aged recalled less than the young and did not benefit as much from greater encoding specificity and deeper processing in CCR. ICR and CCR were correlated, so that expected CCR can be predicted from ICR. The regression of CCR on ICR was linear for young adults, but was piecewise linear for the aged, showing that the relationship between ICR and CCR was not uniform for the aged adults. Lower than expected CCR by a subset of aged without clinical dementia may be a sign of preclinical dementia.

Proportional slowing and addition speed in old and young adults.

An addition and copying task was used to compare processing speed in young and old adults. Consistent with previous studies, no age differences in the problem-size effect were observed (Geary & Wiley, 1991). However, the old adults were slower overall, and an analysis of the distributions of old and young individuals indicated that the form of this slowing was proportional. These analyses also demonstrated that proportional slowing was uniform in the old adults, such that the fastest and slowest old individuals were slowed by the same factor. Because the regression of old-young mean response times can be insensitive to differential age effects, comparisons of old and young distributions are recommended to support claims regarding proportional slowing and uniformity of age effects across individuals. Finally, the results suggest that requiring Ss to initiate a new operation produced a larger age effect than requiring Ss to repeat an operation.

Hand preference and performance effects on line bisection.

Right- and left-handed subjects performed a visual line bisection task with each hand. When bisecting horizontal lines, both groups bisected left of true center regardless of hand used. Regardless of hand preference, bisections were significantly left of center only when subjects performed with their left hand. Left-handed subjects using their left hand deviated significantly further left than right-handed subjects using their left hand. Regardless of hand used, right-handers bisected vertical lines significantly above veridical center. Left-handed subjects were not significantly above center with either hand. The results require both hemispheric advantage and lateralized activation effects for a complete explanation.