Examining the reliability of ADAS-Cog change scores

The purpose of this study was to estimate and examine ways to improve the reliability of change scores on the Alzheimer’s Disease Assessment Scale, Cognitive Subtest (ADAS-Cog). The sample, provided by the Alzheimer’s Disease Neuroimaging Initiative, included individuals with Alzheimer’s disease (AD) (n = 153) and individuals with mild cognitive impairment (MCI) (n = 352). All participants were administered the ADAS-Cog at baseline and 1 year, and change scores were calculated as the difference in scores over the 1-year period. Three types of change score reliabilities were estimated using multivariate generalizability. Two methods to increase change score reliability were evaluated: reweighting the subtests of the scale and adding more subtests. Reliability of ADAS-Cog change scores over 1 year was low for both the AD sample (ranging from .53 to .64) and the MCI sample (.39 to .61). Reweighting the change scores from the AD sample improved reliability (.68 to .76), but lengthening provided no useful improvement for either sample. The MCI change scores had low reliability, even with reweighting and adding additional subtests. The ADAS-Cog scores had low reliability for measuring change. Researchers using the ADAS-Cog should estimate and report reliability for their use of the change scores. The ADAS-Cog change scores are not recommended for assessment of meaningful clinical change.     

A comparison of the diagnostic accuracy of the AD8 and BCAT-SF in identifying dementia and mild cognitive impairment in long-term care residents

We compared the accuracy of the Brief Cognitive Assessment Tool—Short Form (BCAT-SF) and AD8 in identifying mild cognitive impairment (MCI) and dementia among long-term care residents. Psychometric analyses of 357 long-term care residents (n = 228, nursing home; n = 129, assisted living) in Maryland referred for neuropsychological evaluation evidenced robust internal consistency reliability and construct validity for the BCAT-SF. Furthermore, hierarchical logistic regression and receiver operating characteristic curve analyses demonstrated superior predictive validity for the BCAT-SF in identifying MCI and dementia relative to the AD8. In contrast, previously reported psychometric properties or cut scores for the AD8 could not be cross-validated in this long-term care sample. Based on these findings, the BCAT-SF appears to be a more reliable and valid screening instrument than the AD8 for rapidly identifying MCI and dementia in long-term care residents.     

Neuropsychological predictors of conversion to probable Alzheimer disease in elderly with mild cognitive impairment

In the field of neuropsychology, it is essential to determine which neuropsychological tests predict Alzheimer's disease (AD) in people with mild cognitive impairment (MCI) and which cut‐off points should be used to identify people at greater risk for converting to dementia. The aim of the present study was to analyse the predictive value of the cognitive tests included in a neuropsychological battery for conversion to AD among MCI participants and to analyse the influence of some sociodemographic variables – sex, age, schooling – and others, such as follow‐up time and emotional state. A total of 105 participants were assessed with a neuropsychological battery at baseline and during a 3‐year follow‐up period. For the present study, the data were analysed at baseline. During the follow‐up period, 24 participants (22.85%) converted to dementia (2.79 ± 1.14 years) and 81 (77.14%) remained as MCI. The logistic regression analysis determined that the long delay cued recall and the performance time of the Rey figure test were the best predictive tests of conversion to dementia after an MCI diagnosis. Concerning the sociodemographic factors, sex had the highest predictive power. The results reveal the relevance of the neuropsychological data obtained in the first assessment. Specifically, the data obtained in the episodic verbal memory tests and tests that assess visuospatial and executive components may help to identify people with MCI who may develop AD in an interval not longer than 4 years, with the masculine gender being an added risk factor.     

Interpreting Errors in Temporal Orientation in Older Hospital Patients

Normal variation in temporal orientation has been examined in community dwelling, healthy older subjects but not in elderly hospital patients. We examined the validity of errors in different aspects of temporal orientation as a guide to the presence or absence of cognitive impairment orientation in elderly hospital patients in 150 consecutive patients on the day after admission to an acute geriatric unit. Cognitive impairment (delirium or dementia or both) was diagnosed without reference to temporal orientation. Optimum cutoffs for error scores on the different aspects of temporal orientation (date/year/month/day of the week/time of day) were calculated to maximize the sum of sensitivity and specificity for detection of cognitive impairment. Of the 150 patients, 45 (30%) had cognitive impairment. The best cutoffs for detection of cognitive impairment were an error of more than 3 days in the date; any error in the year, month, or day of the week; and an error of more than 1 h in identifying the time of day. Error in identifying the year had the highest positive likelihood ratio (6.4 [95% confidence interval 4.0–10.3]) for detecting cognitive impairment and the lowest negative likelihood ratio (0.1 [0.04–0.3]) for the exclusion of cognitive impairment. Failure to identify the year correctly is the aspect of temporal orientation most closely related to cognitive impairment.     

Just Ignore It? Parents and Genetic Information

This paper discusses whether prospectiveparents ought to find out about their geneticconstitution for reproductive reasons. It isargued that ignoring genetic information can bein line with responsible parenthood or perhapseven recommendable. This is because parenthoodis essentially an unconditional project inwhich parents ought to commit themselves tonurturing any kind of child. Besides, thetraditional reasons offered for theunfortunateness of impairments and the tragicfate of families with disabled children are notconvincing. Other morally problematic outcomesof genetics, such as discrimination againstindividuals with impairments, and limiting freeparental decision making, are alsoconsidered.     

Maternal Sensitivity and the Visual Attentiveness of Children Who Are Deaf

Maternal sensitivity may be even more important for the development of deaf infants' social and cognitive competence than previous research has shown it to be for hearing children. We report ratings of mothers' sensitivity and infants' time in coordinated joint attention (CJA) during play interactions video-taped in a laboratory at 9,12 and 18 months. Participants include 80 dyads in four groups: two matched for hearing status (Deaf or Hearing mothers with deaf or hearing babies), two unmatched for hearing status (Deaf mothers/hearing babies and Hearing mothers/deaf babies). Mothers in matched dyads were rated more sensitive than mothers in unmatched dyads. Deaf infants with Deaf mothers showed more time in CJA compared to infants in unmatched dyads. However, significant correlations of sensitivity and attention were found only for the two unmatched hearing status groups at 18 months. These results are discussed in terms of dyadic hearing status differences, intuitive parenting and developmental stage. © 1996 John Wiley & Sons, Ltd.     

Language Impairment and Sexual Assault of Girls and Women: Findings from a Community Sample

Both children and adults with disabilities face increased prevalence of abuse and assault, including sexual assault. Women and girls are disproportionately the victims of sexual assault in both disabled and nondisabled populations. Communication difficulties have been identified as a factor that may increase the vulnerability of individuals with disabilities to sexual assault. However, few studies have examined whether language impairment increases risk for sexual assault. This study reports on a community sample of children with speech or language impairment, followed to age 25. Sexual assault history was assessed based on two questions from the Composite International Diagnostic Interview Posttraumatic Stress Disorder module. Women with language impairment (n = 33) were more likely than women with unimpaired language (n = 59) to report sexual abuse/assault, controlled for socioeconomic status. Sexual assault was associated with higher rates of psychiatric disorders and poorer functioning. Women with neither language impairment nor a history of sexual assault had fewer psychiatric disorders and higher functioning than women with language impairment and/or a history of sexual assault.     

The attentional blink reveals sluggish attentional shifting in adolescents with specific language impairment

Rapid processing deficits have been the subject of much debate in the literature on specific language impairment (SLI). Hari and Renvall (2001) [Hari, R. & Renvall, H. (2001). Impaired processing of rapid stimulus sequences in dyslexia. Trends in cognitive sciences, 5, 525-532.] proposed that the source of this deficit can be attributed to sluggish attentional shifting abilities. That is, more time is required to shift attention between stimuli. To test this claim, 26 adolescents with SLI (divided into two subgroups to control for differences in non-verbal intelligence) and 14 controls were presented with a rapid serial visual presentation task. In this task participants were asked to detect two visual targets presented serially with distracter items with varying inter-target intervals (i.e., time difference between targets). This task was designed to elicit an attentional blink (AB). The AB describes the phenomenon whereby non-impaired individuals are less likely to report the second of two targets presented within 200-500ms of each other. After controlling for group differences in non-verbal intelligence, the SLI group was found to be significantly less accurate than the control group at successfully reporting the second target at inter-target intervals of 100, 200, 300, 400 and 800ms. The results were interpreted to suggest that adolescents with language impairments have an AB which differs from non-impaired individuals in both magnitude and duration.     

Heart rate variability and drawing impairment in hypoxemic COPD

We studied 54 patients with hypoxemic chronic obstructive pulmonary disease (COPD). The Mini Mental State Examination and the Mental Deterioration Battery were used for neuropsychological assessment. Heart rate variability (HRV) was assessed based on 24-h Holter ECG recording. Mann–Whitney test was used to compare HRV parameters of patients performing normally or abnormally on individual neuropsychological tasks. Spearman’s rho was used to investigate the correlations between HRV parameters and neuropsychological scores, indexes of health status or COPD severity. Patients with defective performance at copying drawings with landmarks (CDL) test (N = 23) had lower very low frequency (VLF) power with respect to patients with normal performance (N = 31) (24 h: median 213; interquartile range 120–282 vs. 309; 188–431 ms², p = 0.043; daytime: 202; 111–292 vs. 342; 194–397 ms², p = 0.039). The CDL score correlated with the VLF power (24 h: ρ = 0.27, p = 0.049; daytime: ρ = 0.30, p = 0.028), and the normalized low frequency/high frequency (LF/HF) ratio (24 h: ρ = 0.27, p = 0.05; daytime: ρ = 0.33, p = 0.015). Sympathetic modulation decreased for increasing severity of COPD. In conclusion, drawing impairment correlates with depressed sympathetic modulation in patients with COPD, and both might be indexes of COPD severity.     

Response speed, contingent negative variation and P300 in Alzheimer’s disease and MCI

Background

Decreased speed of information processing is a hallmark of Alzheimer’s disease (AD) and mild cognitive impairment (MCI). Recent studies suggest that response speed (RS) measures are very sensitive indicators of changes in longitudinal follow-up studies. Insight into the psycho-physiological underpinnings of slowed RS can be provided by measuring the associated event-related potentials (ERP).

Aims

The current study aims to investigate the relation between RS and its psycho-physiological correlates in AD and MCI.

Methods

Fifteen psychoactive drug-naïve AD patients, 20 MCI patients and twenty age-matched, healthy control subjects participated. Response speed was measured during a simple (SRT) and choice reaction time task (CRT). An oddball and contingent negative variation (CNV) paradigm were used to elicit ERP. To evaluate test-retest reliability (TRR), subjects underwent a similar assessment one week after the first.

Results

The SRT and CRT distinguished the patient groups significantly. The P300 amplitude and latency also distinguished the groups and showed a significant correlation with response speed. The CNV amplitude did not reveal a significant difference between groups and also showed a low TRR.The TRR of the SRT, CRT and P300 amplitude and latency in general was moderate to high.The current study suggests that response speed measures on a behavioural and psycho-physiological level deserve attention as a possible marker in the diagnosis and follow-up of AD.