Mild Cognitive Impairment Subtype Performance in Comparison to Healthy Older Controls on the NIH Toolbox and Cogstate.

BACKGROUND: Early detection is necessary for the treatment of dementia. Computerized testing has become more widely used in clinical trials; however, it is unclear how sensitive these measures are to early signs of neurodegeneration. We investigated the use of the NIH Toolbox-Cognition (NIHTB-CB) and Cogstate-Brief computerized neuropsychological batteries in the identification of mild cognitive impairment (MCI) versus healthy older adults [healthy control (HC)] and amnestic (aMCI) versus nonamnestic MCI (naMCI). Exploratory analyses include investigating potential racial differences. METHODS: Two hundred six older adults were diagnosed as aMCI (n = 58), naMCI (n = 15), or cognitively healthy (HC; n = 133). RESULTS: The NIH Toolbox-CB subtests of Flanker, Picture Sequence Memory, and Picture Vocabulary significantly differentiated MCI from HC. Further, subtests from both computerized batteries differentiated patients with aMCI from those with naMCI. Although the main effect of race differences was noted on tests and in diagnostic groups was significant, there were no significant race-by-test interactions. CONCLUSIONS: Computer-based subtests vary in their ability to help distinguish MCI subtypes, though these tests provide less expensive and easier-to-administer clinical screeners to help identify patients early who may qualify for more comprehensive evaluations. Further work is needed, however, to refine computerized tests to achieve better precision in distinguishing impairment subtypes.

Prevalence of REM sleep behavior disorder in multiple system atrophy: a multicenter study and meta-analysis.

OBJECTIVE: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia frequently affecting patients with synucleinopathies, but its exact prevalence in multiple system atrophy (MSA) is unclear. Whether questionnaires alone are sufficient to diagnose RBD is also unknown. METHODS: We performed a cross-sectional study of patients with probable MSA from six academic centers in the US and Europe. RBD was ascertained clinically and with polysomnography; we also performed a meta-analysis according to PRISMA guidelines for studies published before September 2014 that reported the prevalence of RBD in MSA. A random-effects model was constructed using weighted prevalence proportions. Only articles in English were included. Studies were classified into those that ascertained the presence of RBD in MSA clinically and with polysomnography. Case reports or case series (≤ 5 patients) were not included. RESULTS: Forty-two patients completed questionnaires and underwent polysomnography. Of those, 32 (76.1%) had clinically suspected RBD and 34 (81%) had polysomnography-confirmed RBD. Two patients reported no symptoms of RBD but had polysomnography-confirmed RBD. The primary search strategy yielded 374 articles of which 12 met the inclusion criteria. The summary prevalence of clinically suspected RBD was 73% (95 % CI, 62-84%) in a combined sample of 324 MSA patients. The summary prevalence of polysomnography-confirmed RBD was 88 % (95% CI, 79-94%) in a combined sample of 217 MSA patients. INTERPRETATION: Polysomnography-confirmed RBD is present in up to 88% of patients with MSA. RBD was present in some patients that reported no symptoms. More than half of MSA patients report symptoms of RBD before the onset of motor deficits.

Salience Network Functional Connectivity Mediates Association Between Social Engagement and Cognition in Non-Demented Older Adults: Exploratory Investigation.

Background: Social engagement has beneficial effects during cognitive aging. Large-scale cognitive brain network functions are implicated in both social behaviors and cognition. Objective: We evaluated associations between functional connectivity (FC) of large-scale brain cognitive networks and social engagement, characterized by self-reported social network size and contact frequency. We subsequently tested large-scale brain network FC as a potential mediator of the beneficial relationship between social engagement and cognitive performance. Methods: 112 older adults (70.7±7.3 years, range 54.6-89.7; 84 women) completed the Lubben Social Network Scale 6 (LSNS-6), National Alzheimer's Coordinating Center (NACC) Uniform Data Set 3 (UDS-3) cognitive battery, and resting state fMRI. We completed seed-based correlational analysis in the default mode and salience networks. Significant associations between social engagement scores and cognitive performance, as well as between social engagement and FC of brain networks, informed the construction of mediation models. Results: Social engagement was significantly associated with executive function and global cognition, with greater social engagement associated with better cognitive performance. Social engagement was significantly associated with salience network FC, with greater social engagement associated with higher connectivity. Salience network FC partially mediated associations between social engagement and both executive function and global cognition. Conclusions: Our results suggest that the salience network is a key mediator of the beneficial relationship between social engagement and cognition in older adults.

Validation of the National Alzheimer's Coordinating Center (NACC) Lewy Body Disease Module neuropsychological tests.

INTRODUCTION: This study assessed the construct validity and clinical utility of the National Alzheimer's Coordinating Center Lewy Body Dementia (LBD) Module, consisting of the Speeded Attention and Noise Pareidolia Tasks. METHODS: Participants included 459 older adults diagnosed as cognitively normal (n = 202), or with non-amnestic mild cognitive impairment (n = 61), amnestic mild cognitive impairment (n = 96), Alzheimer's disease dementia (n = 44), or LBD (n = 56). RESULTS: Speeded Attention demonstrated strong convergent validity and moderate discriminant validity when compared to established neuropsychological tests. Noise Pareidolia demonstrated strong discriminant validity, but limited convergent validity. Noise Pareidolia scores were significantly lower in those with reported hallucinations, delusions, or REM sleep behavior disorder symptoms. LBD Module tests discriminated well between cognitively normal adults and those with LBD. DISCUSSION: The LBD Module demonstrates promising construct validity and clinical utility, which support its use across research and clinical settings.

Caregiver support service needs for patients with mild cognitive impairment and Alzheimer disease.

Little is known about the service needs for persons caring for individuals with mild cognitive impairment (MCI). In this study, the level of support service need for caregivers of individuals diagnosed with Alzheimer disease (AD; N=55) and MCI (N=25) was compared with normal controls (N=44). Study partners (ie, caregivers) completed questionnaires about their service needs and participants' neurobehavioral symptoms, functional abilities, and frailty. Total, social, and mental health service needs were significantly different among the 3 groups (P<0.0001), with MCI and AD caregivers reporting more need for services as compared with the normal control group. There was no significant difference between MCI and AD groups for total and social service need. In the MCI group, caregiver's service need was related to neurobehavioral symptoms and frailty, whereas service need among the AD caregivers was related to functional disability and frailty. Caregivers of individuals with MCI are already experiencing a need for increased services comparable to that of individuals caring for AD patients, though the pattern of patient-related factors is different between the 2 patient groups. These findings suggest possible areas of intervention that could be considered at the earliest stages of memory loss.