Gail Kuslansky

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.

Validity of divided attention tasks in predicting falls in older individuals: A preliminary study

OBJECTIVES: Although cognitive impairment is known to be a major risk factor for falls in older individuals, the role of cognitive tests in predicting falls has not been established. Limited attentional resources may increase the risk for falls in older individuals. We examined the reliability and validity of divided attention tasks, walking while talking (WWT), in predicting falls.

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 (≤70 mm Hg) was associated with increased risk of AD (HR vs normal diastolic BP group 1.91, 95% CI 1.05 to 3.48). Subjects with persistent low BP over 2 years had higher risk of developing dementia (HR 2.19, 95% CI 1.27 to 3.77). Conclusions: Low diastolic pressure is associated with higher risk of dementia in elderly individuals over age 75. Dementia risk was higher in subjects with persistently low BP.

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.

Screening for Dementia by Telephone Using the Memory Impairment Screen

Objectives: To develop and assess telephone‐based screening tests for dementia, especially Alzheimers disease (AD).

Screening for Alzheimer's disease: The memory impairment screen versus the conventional three-word memory test

OBJECTIVES: To improve screening for Alzheimers disease (AD) with the Memory Impairment Screen (MIS), a 4‐minute, four‐item delayed free and cued recall memory test with controlled learning and high discriminative validity. To assess the discriminative validity of the MIS for AD and to compare it with the conventional three‐word memory test, a delayed free recall task, widely recommended as a dementia‐screening test in clinical practice.

Cognitive performance in surgically menopausal women on estrogen.

Article abstract 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.

Detecting dementia with the Hopkins Verbal Learning Test and the Mini-Mental State Examination

The Hopkins Verbal Learning Test (HVLT) and the Mini-Mental State Examination (MMSE) were administered to 323 non-demented elderly and 70 individuals who meet DSM-IV criteria for dementia in order to compare the validity of these two measures for detecting mild dementia and for the two most common dementia subtypes, Alzheimers disease (AD) and vascular dementia (VaD). The study was conducted in an elderly, ethnically diverse community-dwelling population. Sensitivity, specificity, positive and negative predictive values were calculated over a range of clinically relevant cut scores for each test. We analyzed the influence of age, education, reading ability and sex on test performance using logistic regression models. When sensitivity is held constant at 0.69, the specificity for the HVLT total recall was 0.89 and the MMSE 0.82 for all dementias (P=.10). Age, sex and education did not significantly influence test performance for either test in this sample. Results were similar for AD and VaD. However, while adding a measure of reading ability to the regression models did not affect the overall dementia model, it resulted in improved specificities when combined with the MMSE for AD and combined with the HVLT for VaD. Additional tests such as reading ability can improve discrimination of dementia subtypes. The modest sensitivity of either the HVLT or the MMSE alone suggests that further neuropsychological evaluation is required to confirm dementia diagnosis.

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.