Cognitive training with virtual reality at older people longterm residences

Purpose: to describe a series of cases of older people with a clinical diagnosis of mild cognitive impairment or dementia at elderly long-term residences using virtual reality as cognitive rehabilitation.Methods: this study is a series of cases. Older adults diagnosed with mild cognitive impairment or dementia were included. Elderly people with visual and/or hearing problems that made it impossible to carry out the training were excluded. The same tests were used after intervention and at follow up after 15 days.Results: final sample consisted of 13 women and the mean age was 81.77 years (± 6.94). Patients were divided into 2 groups: mild cognitive impairment group and the dementia group. According to the therapeutic objectives aimed at improving fluency, among the results, the improvement in the scores to the group mild cognitive impairment stands out for the phonemic verbal fluency tests 23.63 (± 12.72) pre-test and 29.50 (± 11.14) post-test. There was an improvement in mild cognitive impairment group scores for the phonemic verbal fluency tests 23.63 (± 12.72) pretest and 29.50 (± 11.14) post-test. In the dementia group, test scores were 10 (± 5, 47) pretest and 12.80 (± 5.72) post-test. On the semantic verbal fluency test, the mild cognitive impairment group showed improvement 11.00 (± 3.62) pretest and 13.88 (± 6.03) post-test, while the dementia group test scores were 7.60 (± 4.56) pretest and 8.20 (± 5.12) post-test.Conclusion: regarding phonemic verbal fluency, virtual reality may be a good resource for improving the performance of older adults with mild cognitive impairment. Results were not maintained in the medium term, showing the importance of continual training.

Spatial Navigation Game in EEG-integrated VR for Screening Cognitive Impairment: Protocol for Feasibility and Pilot Study (Preprint)

BACKGROUND Spatial navigation impairment is recognized as a potential marker of preclinical dementia. Virtual reality (VR) technology has been introduced as a promising framework for dementia research. Recent work has demonstrated further possibilities that integrating electroencephalography (EEG) sensors into VR headsets can provide invaluable information relevant to cognitive impairment. OBJECTIVE The aim of this study is to explore the feasibility of spatial navigation assessment in EEG-integrated VR devices for assessing cognitive impairment. This study will further investigate the neurophysiological characteristics of wearable EEG sensors during a VR spatial navigation game. METHODS Participants recruited for the study will be grouped into three based on their cognitive status (mild Alzheimer’s disease group, mild cognitive impairment group, and healthy controls). The spatial navigation game is designed based on the hidden goal task to assess egocentric and allocentric spatial information processing. As outcome measures, spatial navigation errors, spectral density characteristics of EEG signals, and behavioral responses in VR will be analyzed. RESULTS A spatial navigation game for VR was developed in March 2021. Recruitment commenced in June 2021. CONCLUSIONS The results of this study will provide a comprehensive understanding of VR-based spatial navigation assessment, in terms of cognitive measurement including early screening. If positive, our approach based on EEG-integrated VR devices could constitute an effective cognitive impairment screening test tool that can provide brain dynamic characteristics as well as information on spatial navigation deficits.

Association of Odor Identification Ability With Amyloid-β and Tau Burden: A Systematic Review and Meta-Analysis

Background: The associations between olfactory identification (OI) ability and the Alzheimer's disease biomarkers were not clear.Objective: This meta-analysis aimed to examine the associations between OI and Aβ and tau burden.Methods: Electronic databases (PubMed, Embase, PsycINFO, and Google Scholar) were searched until June 2019 to identify studies that reported correlation coefficients or regression coefficients between OI and Aβ or tau levels measured by positron emission tomography (PET) or cerebrospinal fluid (CSF). Pooled Pearson correlation coefficients were computed for the PET imaging and CSF biomarkers, with subgroup analysis for subjects classified into different groups.Results: Nine studies met the inclusion criteria. Of these, five studies (N = 494) involved Aβ PET, one involved tau PET (N = 26), and four involved CSF Aβ or tau (N = 345). OI was negatively associated with Aβ PET in the mixed (r = −0.25, P = 0.008) and cognitively normal groups (r = −0.15, P = 0.004) but not in the mild cognitive impairment group. A similar association with CSF total tau in the mixed group was also observed. No association was found between OI and CSF phosphorylated tau or Aβ42 in the subgroup analysis of the CSF biomarkers. Due to a lack of data, no pooled r value could be computed for the association between the OI and tau PET.Conclusion: The associations between OI ability and Aβ and CSF tau burden in older adults are negligible. While current evidence does not support the association, further studies using PET tau imaging are warranted.

Serum Tau Proteins as Potential Biomarkers for the Assessment of Alzheimer’s Disease Progression

Total tau (t-tau) and phosphorylated tau (p-tau) protein elevations in cerebrospinal fluid (CFS) are well-established hallmarks of Alzheimer’s disease (AD), while the associations of serum t-tau and p-tau levels with AD have been inconsistent across studies. To identify more accessible non-invasive AD biomarkers, we measured serum tau proteins and associations with cognitive function in age-matched controls (AMC, n = 26), mild cognitive impairment group (MCI, n = 30), and mild-AD group (n = 20) according to the Mini-mental State Examination (MMSE), Clinical Dementia Rating (CDR), and Global Deterioration Scale (GDS) scores. Serum t-tau, but not p-tau, was significantly higher in the mild-AD group than AMC subjects (p < 0.05), and there were significant correlations of serum t-tau with MMSE and GDS scores. Receiver operating characteristic (ROC) analysis distinguished mild-AD from AMC subjects with moderate sensitivity and specificity (AUC = 0.675). We speculated that tau proteins in neuronal cell-derived exosomes (NEX) isolated from serum would be more strongly associated with brain tau levels and disease characteristics, as these exosomes can penetrate the blood-brain barrier. Indeed, ELISA and Western blotting indicated that both NEX t-tau and p-tau (S202) were significantly higher in the mild-AD group compared to AMC (p < 0.05) and MCI groups (p < 0.01). In contrast, serum amyloid β (Aβ1–42) was lower in the mild-AD group compared to MCI groups (p < 0.001). During the 4-year follow-up, NEX t-tau and p-tau (S202) levels were correlated with the changes in GDS and MMSE scores. In JNPL3 transgenic (Tg) mice expressing a human tau mutation, t-tau and p-tau expression levels in NEX increased with neuropathological progression, and NEX tau was correlated with tau in brain tissue exosomes (tEX), suggesting that tau proteins reach the circulation via exosomes. Taken together, our data suggest that serum tau proteins, especially NEX tau proteins, are useful biomarkers for monitoring AD progression.

Disrupted white matter integrity is associated with cognitive deficits in patients with amnestic mild cognitive impairment: An atlas-based study

Objective: This study investigated white matter integrity in patients with amnestic mild cognitive impairment by diffusion tensor imaging. Methods: A total of 83 patients with amnestic mild cognitive impairment and 85 elderly healthy controls underwent neuropsychological testing and a diffusion tensor imaging scan. Whole-brain white matter data were parcellated into 50 regions based on the anatomical ICBM-DTI-81 atlas, and regional diffusion metrics consisting of fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity were calculated for each region. Diffusion tensor imaging indices were compared between groups, and it was determined that between-group differences were significantly correlated with neurocognitive performance. Results: Relative to the healthy controls group, the amnestic mild cognitive impairment group exhibited poorer cognitive performance in all neuropsychological tests except the complex figure test ( p = 0.083) and showed decreased mean fractional anisotropy in the fornix, increased mean diffusivity in the fornix and bilateral uncinate fasciculus, elevated axial diffusivity in the fornix and genu of corpus callosum, and elevated radial diffusivity in the fornix and bilateral uncinate fasciculus ( p < 0.05). Behaviorally, integrity of the bilateral uncinate fasciculus was correlated positively with episodic memory function, while left uncinate fasciculus integrity was positively associated with language function in the amnestic mild cognitive impairment group ( p < 0.05). Conclusion: White matter abnormalities in neural pathways associated with memory were correlated with neurocognitive deficiencies in amnestic mild cognitive impairment. Given that amnestic mild cognitive impairment is putatively a prodromal syndrome for Alzheimer’s disease, this study furthers our understanding of the white matter changes associated with Alzheimer’s disease pathogenesis in the predementia stage.