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This paper presents updated analyses on the genetic associations of sleep disruption in individuals with Alzheimer’s disease (AD). We published previously a study of the association between single nucleotide polymorphisms (SNPs) found in eight genes related to circadian rhythms and objective measures of sleep-wake disturbances in 124 individuals with AD. Here, we present new relevant analyses using polygenic risk scores (PRS) and variable number tandem repeats (VNTRs) enumerations. PRS were calculated using the genetic data from the original participants and relevant genome wide association studies (GWAS). VNTRs for the same circadian rhythm genes studied with SNPs were obtained from a separate cohort of participants using whole genome sequencing (WGS). Objectively (wrist actigraphy) determined wake after sleep onset (WASO) was used as a measure of sleep disruption. None of the PRS were associated with sleep disturbance. Computer analyses using VNTRseek software generated a total of 30 VNTRs for the circadian-related genes but none appear relevant to our objective sleep measure. In addition, of 71 neurotransmitter function-related genes, 29 genes had VNTRs that differed from the reference VNTR, but it was not clear if any of these might affect circadian function in AD patients. Although we have not found in either the current analyses or in our previous published analyses of SNPs any direct linkages between identified genetic factors and WASO, research in this area remains in its infancy.
QuantiFERON tuberculosis tests (QFT) reverted in (612) 77% of 1,094 low-risk healthcare workers (HCW) testing less than 1.16 IU/mL. Of HCW testing greater than 1.1 IU/mL, 33 (59%) of 56 with negative tuberculin skin tests (TST) reverted vs 8 (6%) of 125 with positive TSTs. Retesting low-risk QFT-positive and TST-negative HCW is prudent.
Infect. Control Hosp. Epidemiol. 2016;37(4):478–482
Placebo responses raise significant challenges for the design of clinical trials. We report changes in agitation outcomes in the placebo arm of a recent trial of citalopram for agitation in Alzheimer's disease (CitAD).
In the CitAD study, all participants and caregivers received a psychosocial intervention and 92 were assigned to placebo for nine weeks. Outcomes included Neurobehavioral Rating Scale agitation subscale (NBRS-A), modified AD Cooperative Study-Clinical Global Impression of Change (CGIC), Cohen-Mansfield Agitation Inventory (CMAI), the Neuropsychiatric Inventory (NPI) Agitation/Aggression domain (NPI A/A) and Total (NPI-Total) and ADLs. Continuous outcomes were analyzed with mixed-effects modeling and dichotomous outcomes with logistic regression.
Agitation outcomes improved over nine weeks: NBRS-A mean (SD) decreased from 7.8 (3.0) at baseline to 5.4 (3.2), CMAI from 28.7 (6.7) to 26.7 (7.4), NPI A/A from 8.0 (2.4) to 4.9 (3.8), and NPI-Total from 37.3 (17.7) to 28.4 (22.1). The proportion of CGI-C agitation responders ranged from 21 to 29% and was significantly different from zero. MMSE improved from 14.4 (6.9) to 15.7 (7.2) and ADLs similarly improved. Most of the improvement was observed by three weeks and was sustained through nine weeks. The major predictor of improvement in each agitation measure was a higher baseline score in that measure.
We observed significant placebo response which may be due to regression to the mean, response to a psychosocial intervention, natural course of symptoms, or nonspecific benefits of participation in a trial.
Naming or word-finding tasks are a mainstay of the typical neuropsychological evaluation, particularly with older adults. However, many older adults have significant visual impairment and there are currently no such word-finding tasks developed for use with older visually impaired populations. This study presents a verbal, non-visual measure of word-finding for use in the evaluation of older adults with possible dysnomia. Stimuli were chosen based on their frequency of usage in everyday spoken language. A 60-item scale was created and given to 131 older Veterans. Rasch analyses were conducted and differential item functioning assessed to eliminate poorly-performing items. The final 55-item scale had a coefficient alpha of 0.84 and correlated with the Neuropsychological Assessment Battery Naming test, r=0.84, p<.01, Delis-Kaplan Executive Function System (D-KEFS) Category Fluency, r=0.45, p<.01, and the D-KEFS Letter Fluency, r=0.40, p<.01. ROC analyses found the measure to have sensitivity of 79% and specificity of 85% for detecting dysnomia. Patients with dysnomia performed worse on the measure than patients with intact word-finding, t(84)=8.2, p<.001. Patients with no cognitive impairment performed significantly better than patients with mild cognitive impairment, who performed significantly better than patients with dementia. This new measure shows promise in the neuropsychological evaluation of word-finding ability in older adults with or without visual impairment. Future directions include the development of a shorter version and the generation of additional normative data. (JINS, 2015, 21, 1–10)
Previous studies have consistently reported age-related changes in cognitive abilities and brain structure. Previous studies also suggest compensatory roles for specialized training, skill, and years of education in the age-related decline of cognitive function. The Stanford/VA Aviation Study examines the influence of specialized training and skill level (expertise) on age-related changes in cognition and brain structure. This preliminary report examines the effect of aviation expertise, years of education, age, and brain size on flight simulator performance in pilots aged 45–68 years. Fifty-one pilots were studied with structural magnetic resonance imaging, flight simulator, and processing speed tasks. There were significant main effects of age (p < .01) and expertise (p < .01), but not of whole brain size (p > .1) or education (p > .1), on flight simulator performance. However, even though age and brain size were correlated (r = −0.41), age differences in flight simulator performance were not explained by brain size. Both aviation expertise and education were involved in an interaction with brain size in predicting flight simulator performance (p < .05). These results point to the importance of examining measures of expertise and their interactions to assess age-related cognitive changes. (JINS, 2010, 16, 412–423.)
Background: Sleep disturbance is common in caregivers of older adults with memory disorders. Little is known, however, about the implications of caregivers’ poor sleep with regard to their physical functioning.
Methods: In this cross-sectional study, we investigated the association between objectively measured sleep and self-reported physical functioning in 45 caregivers (mean age = 68.6 years) who completed the Beck Depression Inventory-II, the Medical Outcomes Study SF-36, and the Mini-mental State Examination, and wore an actigraph for at least three days. Our primary predictors were actigraphic sleep parameters, and our outcome was the SF-36 Physical Functioning subscale.
Results: In multivariate-adjusted linear regression analyses, each 30-minute increase in caregivers’ total sleep time was associated with a 2.2-point improvement in their Physical Functioning subscale scores (unstandardized regression coefficient (B) = 2.2, 95% confidence interval (CI) 1.0–3.4, p = 0.001). In addition, each 10-minute increase in time awake after initial sleep onset was associated with a 0.5-point decrease on the Physical Functioning subscale, although this was not statistically significant (B = −0.5, 95% CI −1.1, 0.1, p = 0.09).
Conclusions: Our findings suggest that shorter sleep duration is associated with worse self-reported physical functioning in caregivers. Longitudinal studies are needed to determine whether poor sleep predicts functional decline in caregivers.
Objectives: To improve performance with mnemonic techniques for remembering words and proper names. Design: For word recall, a 2 × 2 factorial in which type of pretraining and length of training were between-subjects manipulations. For proper name recall, a two-group design in which type of pretraining was manipulated between subjects. Setting: Community. Participants: 268 community-dwelling adults over the age of 55 years who wished to improve their memory. Measurements: Recall of words and proper names both before and after training in mnemonics. Intervention: Participants received a 2-week training course on two mnemonic techniques, the method of loci for words and a name association technique for proper names. Results: There was no effect of the pretraining manipulation on proper name recall. For word recall, however, a multiple regression that included age indicated that the older-old participants benefited more from a combination of comprehensive pretraining and extended mnemonic training than did the younger-old. Conclusions: Increased training time coupled with a comprehensive pretraining regimen can improve the performance of the older-old in using mnemonics; this improved performance cannot be attributed solely to enhanced knowledge of the mnemonic.
Major advances in understanding the physiology and genetics of circadian rhythm in the past decade challenge the researcher of sleep/wake disorders in Alzheimer's disease (AD) to distinguish patient characteristics stable across the course of illness (“traits”) from characteristics that vary with stage of illness (“states”). A components-of-variance approach with a repeated measures model was used to examine the between-subjects variance over time (“trait”) vs. within-subjects (“state”) variance in 42 patients with probable AD followed, on average, over 2 years on actigraphic sleep/wake measures. Mental status scores indexed stage of illness. Actigraphic measures of sleep efficiency and circadian rhythmicity appeared predominantly “trait,” with between-individual differences accounting for over 55% of variance compared to the less than 5% of variance related to stage of cognitive impairment. We discuss how “state-trait” analyses can be helpful in identifying areas of assessment most likely to be fruitful objectives of physiologic and genetic research on sleep/wake disturbance in AD.
We investigated the relationship between basal cortisol and dehydroepiandrosterone (DHEA) levels and impairment in different cognitive and noncognitive measures and the possible interaction of DHEA with hypercortisolemia in dementia in 27 patients diagnosed with Alzheimer's disease (AD). There were 17 men and 10 women. Patients were mildly to moderately cognitively impaired at the time of the initial cortisol measures. Patients were administered the Alzheimer's Disease Assessment Scale (ADAS) and Folstein Mini-Mental State Examination (MMSE) at approximately 6-month intervals. Cortisol and DHEA were determined using conventional 125I radioimmunoassay procedures. Pearson product-moment correlations among cortisol and DHEA measures and both initial and longitudinal clinical measures were calculated. There was a relationship between baseline 8 a.m. cortisol levels and cognitive function at the initial testing as measured by the ADAS cognitive measure, with higher cortisol levels being associated with a greater level of impairment. We did not document a relationship between cortisol or DHEA levels and noncognitive measures. There was a significant correlation between both the initial MMSE and ADAS cognitive measures and initial DHEA level, with lower DHEA levels unexpectedly being associated with better performance on these measures. The initial DHEA levels did not predict decline in cognitive function over time. These findings bring into question the potential usefulness of DHEA as a therapeutic agent.
Objectives: To evaluate the impact of external memory devices on the efficacy of a package of internal mnemonic techniques. Participants wrote two types of lists during the study phase: (a) a list of study words and/or (b) a loci list. At recall, participants were not allowed to refer to either of the lists they had written during the study. Design: 2 × 2 factorial with writing study words (“write” or “not write”) and writing down a previously established loci list (“write” or “not write”) manipulated as between-participants variables. Participants: 68 community-dwelling adults 55 years of age and older who wished to improve their memory. Measurements: Free word recall. Results: There were statistically significant effects of writing the loci list, but not of writing the list of study words. Scores were higher when participants wrote the loci lists compared to when they did not. Conclusions: Use of external mnemonics may enhance the efficacy of internal mnemonics, even when the external mnemonic is not used at the time of recall.
Objectives: To identify profiles of subjects who respond to mnemonic training for serial word and proper name recall. Design: Analysis of J. O. Brooks et al.'s (1999) mnemonic training data using Quality Receiver Operating Characteristic (QROC) and longitudinal regression analyses (LRA). Setting: Community. Participants: 224 community-dwelling adults 55 years of age and older who wished to improve their memory. Measurements: Performance on serial word and proper name tests; performance on cognitive ability tests. Results: Although the QROC and LRA identified several common predictors (baseline performance, mental rotation ability, and paired associate learning), the QROC identified additional predictors and cognitive ability profiles associated with successful response. Conclusions: Similar degrees of response to mnemonic training are associated with heterogeneous cognitive profiles. This finding highlights the fact that participants rely on a variety of abilities to derive benefit from mnemonic training and thus suggests different avenues from which to approach this training.
Objectives: To assess the longitudinal effects of acetyl-L-carnitine (ALC) on patients diagnosed with Alzheimer's disease. Design: Longitudinal, double-blind, parallel-group, placebocontrolled. Setting: Twenty-four outpatient sites across the United States. Participants: A total of 334 subjects diagnosed with probable Alzheimer's disease by NINCDS-ADRDA criteria. These data were originally reported by Thal and colleagues (1996). Measurements: Cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS) given every 3 months for 1 year. Results: The average rate of change was estimated using the trilinear approach, which allows for periods of both change and stability. Both the ALC group and the placebo group exhibited the same mean rate of change on the ADAS (0.68 points/month). However, a multiple regression analysis revealed a statistically significant Age × Drug interaction characterized by younger subjects benefiting more from ALC treatment than older subjects. Further analyses suggested that the optimal, though not statistically significant, cutpoint for ALC benefit was 61 years of age. Conclusions: ALC slows the progression of Alzheimer's disease in younger subjects, and the use of the trilinear approach to estimate the average rate of change may prove valuable in pharmacological trials.
The question of whether Mini-Mental State Examination scores should be adjusted for age and educational levels to screen for dementia in clinical populations is reexamined in the results of a recent study supporting adjustment. If the criterion is to identify the most accurate screening procedure for each sociodemographic subgroup, the evidence indicates that the unadjusted scores are preferable. Other criteria might lead to different conclusions. The validities of some of these criteria are questionable because they have the flaw that they are easily satisfied by using random decision procedures.
The Geriatric Depression Scale (GDS) is commonly used to measure depression in the elderly. However, there have been no reports of the underlying structure of the GDS. To this end, the GDS was administered to 326 community-dwelling elderly subjects, and the data were subjected to a factor analysis. A five-factor solution was selected and, after a varimax rotation, the factors that emerged could be described as: (1) sad mood, (2) lack of energy, (3) positive mood, (4) agitation, and (5) social withdrawal. This solution accounted for 42.9% of the variance. Knowledge of the factor structure should aid both clinicians and researchers in the interpretation of responses on the GDS.
The Mini-Mental State Examination (MMSE) is a commonly used instrument for assessing mental impairment. Previous proposals for its underlying structure have focused on scores obtained from a single administration of the test. Because the MMSE is widely used in longitudinal studies, we examined the pattern of relations among the rates of chance of the items. Data were obtained from 63 subjects for 1.5 years or more. The relations among the rates of change of the MMSE items were described by a five-factor solution that accounted for 75% of the variance and comprised factors pertaining to orientation and concentration, obeying commands, learning and repetition, language, and recall. This was in contrast to the structure of the scores obtained from a single administration of the MMSE, which was best described by a two-factor solution. In order to provide a clinical validation, factor scores derived from the MMSE factors were used to predict scores on the Memory and Behavior Problems Checklist and the Brief Cognitive Rating Scale.
This study explored problems older adults experience when using a mnemonic technique known as the method of loci. Older subjects received six hours of imagery, judgment, and relaxation pretraining followed by mnemonic training for either four or six hours (Regular or Extended training, respectively). At the end of training, subjects were given a list of the constituent steps of the method of loci and asked to indicate which, if any, were problematic. The factor structure of the relations among the problems varied according to the length of the training subjects received. Specifically, the factor structure of the difficulties reported by the Regular training group reflected problems with using the steps involved in the application of the method of loci, whereas for the Extended training group the factor structure reflected problems with abilities called upon in using the technique. Thus, even with Extended training, subjects may need additional pretraining to develop specific abilities necessary for the successful application of the mnemonic.
A large percentage of older adults must endure at least one chronic medical illness. Clinically significant depression and anxiety are common among these patients. Specific psychotherapy approaches as well as adaptations required to address the unique issues of this population have not been delineated in the literature. We outline a cognitive-behavioral therapy approach and discuss five treatment issues we have found to be important for this population. These issues include: (1) resolving practical barriers to participation; (2) accepting depression as a separate and reversible problem; (3) limiting excess disability; (4) counteracting the loss of important social roles and autonomy; and (5) challenging the perception of being a “burden.” A case study of a chronic obstructive pulmonary disease (COPD) patient with depression is presented and recommendations for future research are suggested.
The purpose of this paper was to use the Wechsler Adult Intelligence Scale (WAIS) to further define the nature of the underlying factors of the Mini-Mental State Examination (MMSE) as proposed by Tinklenberg et al. (1990). The MMSE was administered to 51 patients once every 6 months for at least one year; the WAIS was administered only at the beginning of the study. Stepwise regression analyses yielded these results: for the Following Commands factor, the best correlate was the Comprehension subtest; for the Language Repetition factor, the best correlate was the Picture Arrangement subtest; and for the Language Expression factor, the best correlates were the Digit Symbol and Object Assembly subtests. These relations help clarify the correlates of decline of AD patients on the MMSE.
Neuroimaging and lesion studies have demonstrated
that hippocampal volume correlates with memory performance,
but material-specific lateralization of this structure-function
relationship has been inconsistent. This MRI study examined
the relative contributions of left and right temporal lobe
volumes to verbal and nonverbal recognition memory in a
group of 20 Alzheimer's disease (AD) patients. There
was a significant relationship between extent of right
hippocampal and right temporal gray matter tissue volume
deficit and performance on the face recognition subtest
of the Warrington Recognition Memory Test. The face recognition
test correlated with right hemisphere volume but not to
left, indicating a material-specific relationship between
brain structure and function in this patient group. Right
temporal horn volume did not account for a significant
proportion of variance in face recognition memory. Although
word recognition was not significantly correlated with
either left or right hippocampal volume in the total group,
there was a strong correlation between left hippocampal
volume and word recognition memory in the female AD patients.
Thus, face recognition shows a material specific relationship
with select lateralized hippocampal and temporal cortical
volumes in AD patients, regardless of gender, whereas the
verbal recognition–left-hippocampal volume relationship
may be mediated by gender. (JINS, 1998, 4,