scholarly journals EEG microstate complexity for aiding early diagnosis of Alzheimer’s disease

2019 ◽  
Author(s):  
Luke Tait ◽  
Francesco Tamagnini ◽  
George Stothart ◽  
Edoardo Barvas ◽  
Chiara Monaldini ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Clinical Tool ◽  
Non Invasive ◽  
Frontoparietal Network ◽  
And Control ◽  
Electroencephalogram Eeg ◽  
Independent Cohort

AbstractIntroductionElectroencephalogram (EEG) is a potentially useful clinical tool for aiding diagnosis of Alzheimer’s disease (AD). We hypothesized we can increase the accuracy of EEG for aiding diagnosis of AD using microstates, which are epochs of quasi-stability at the millisecond scale.MethodsEEG was collected from two independent cohorts of AD and control participants and a cohort of mild cognitive impairment (MCI) patients with four-year clinical follow-up. Microstates were analysed, including a novel measure of complexity.ResultsMicrostate complexity significantly decreased in AD, and when combined with a spectral EEG measure, could classify AD with sensitivity and specificity >80%. These results were validated on an independent cohort and were also found to be generalizable to predict progression from MCI to AD. Additionally, microstates associated with the frontoparietal network were altered in AD.DiscussionEEG has the potential to be a non-invasive functional biomarker that predicts progression from MCI to AD.

Elucidating the risk factors for progression from amyloid-negative amnestic mild cognitive impairment to dementia

2020 ◽  
Vol 17 ◽  
Author(s):  
Hyung-Ji Kim ◽  
Jae-Hong Lee ◽  
E-nae Cheong ◽  
Sung-Eun Chung ◽  
Sungyang Jo ◽  
...  
Keyword(s):  
Risk Factors ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Amnestic Mild Cognitive Impairment ◽  
Amyloid Pet ◽  
Clinical Progression ◽  
Amnestic Mci

Background: Amyloid PET allows for the assessment of amyloid β status in the brain, distinguishing true Alzheimer’s disease from Alzheimer’s disease-mimicking conditions. Around 15–20% of patients with clinically probable Alzheimer’s disease have been found to have no significant Alzheimer’s pathology on amyloid PET. However, a limited number of studies had been conducted this subpopulation in terms of clinical progression. Objective: We investigated the risk factors that could affect the progression to dementia in patients with amyloid-negative amnestic mild cognitive impairment (MCI). Methods: This study was a single-institutional, retrospective cohort study of patients over the age of 50 with amyloidnegative amnestic MCI who visited the memory clinic of Asan Medical Center with a follow-up period of more than 36 months. All participants underwent brain magnetic resonance imaging (MRI), detailed neuropsychological testing, and fluorine-18[F18]-florbetaben amyloid PET. Results: During the follow-up period, 39 of 107 patients progressed to dementia from amnestic MCI. In comparison with the stationary group, the progressed group had a more severe impairment in verbal and visual episodic memory function and hippocampal atrophy, which showed an Alzheimer’s disease-like pattern despite the lack of evidence for significant Alzheimer’s disease pathology. Voxel-based morphometric MRI analysis revealed that the progressed group had a reduced gray matter volume in the bilateral cerebellar cortices, right temporal cortex, and bilateral insular cortices. Conclusion: Considering the lack of evidence of amyloid pathology, clinical progression of these subpopulation may be caused by other neuropathologies such as TDP-43, abnormal tau or alpha synuclein that lead to neurodegeneration independent of amyloid-driven pathway. Further prospective studies incorporating biomarkers of Alzheimer’s diseasemimicking dementia are warranted.

Searching for Primary Predictors of Conversion from Mild Cognitive Impairment to Alzheimer’s Disease: A Multivariate Follow-Up Study

2016 ◽  
Vol 52 (1) ◽  
pp. 133-143 ◽  
Author(s):  
María Eugenia López ◽  
Agustín Turrero ◽  
Pablo Cuesta ◽  
David López-Sanz ◽  
Ricardo Bruña ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Follow Up Study

scholarly journals Anticholinergics and Benzodiazepines on Cognitive Impairment among Elderly with Alzheimer’s Disease: a One year Follow-Up Study

2019 ◽  
Author(s):  
Rewadee Jenraumjit ◽  
Surarong Chinwong ◽  
Dujrudee Chinwong ◽  
Tipaporn Kanjanarach ◽  
Thanat Kshetradat ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Psychological Symptoms ◽  
Esterase Inhibitors ◽  
One Year ◽  
State Examination ◽  
Harmful Effects

Abstract Objective Age-associated decline in central cholinergic activity makes older adults susceptible to harmful effects of anticholinergics (ACs). Evidence exists of an association between effects of AC medications on cognition. This retrospective cohort study examines how ACs affect cognition among older adults with Alzheimer’s disease (AD) who received acetylcholine esterase inhibitors (AChEIs) over the course of 12 months. Results A total of 133 (80% women, mean age 78.38 years, SD 7.4) were recruited. No difference in sex, age and comorbid diseases was observed between participants who took ACs, Benzodiazepines (BZDs) and AChEIs. The most common prescribed ACs was quetiapine, being used for behavioral and psychological symptoms (BPSD). Multilevel analysis showed that the change of mental state examination scores were significantly predicted in the group using ACs (t (169), -2.52, p = .020) but not with the groups using BZD (t (162), 0.84, p = .440). Evidence showed that older adults with Alzheimer’s disease and exposed to ACs exhibited lower global cognitive scores than those without AC exposure. Using ACs could be a trade-off between controlling BPSD and aggravating cognitive impairment. Highlighting the awareness of the potential anticholinergic effect is important and may be the best policy.

Subjective cognitive impairment and Alzheimer's disease: a two year follow up of 51 subjects during two years

2015 ◽  
Vol 13 (4) ◽  
pp. 462-471 ◽  
Author(s):  
Nathalie Sambuchi ◽  
Isabelle Muraccioli ◽  
Béatrice Alescio-Lautier ◽  
Véronique Paban ◽  
Roland Sambuc ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Subjective Cognitive Impairment

scholarly journals Non-invasive in vivo hyperspectral imaging of the retina for potential biomarker use in Alzheimer’s disease

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xavier Hadoux ◽  
Flora Hui ◽  
Jeremiah K. H. Lim ◽  
Colin L. Masters ◽  
Alice Pébay ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Hyperspectral Imaging ◽  
Spectral Difference ◽  
Non Invasive ◽  
Potential Biomarker ◽  
Negative Controls ◽  
The Brain ◽  
Independent Cohort

Abstract Studies of rodent models of Alzheimer’s disease (AD) and of human tissues suggest that the retinal changes that occur in AD, including the accumulation of amyloid beta (Aβ), may serve as surrogate markers of brain Aβ levels. As Aβ has a wavelength-dependent effect on light scatter, we investigate the potential for in vivo retinal hyperspectral imaging to serve as a biomarker of brain Aβ. Significant differences in the retinal reflectance spectra are found between individuals with high Aβ burden on brain PET imaging and mild cognitive impairment (n = 15), and age-matched PET-negative controls (n = 20). Retinal imaging scores are correlated with brain Aβ loads. The findings are validated in an independent cohort, using a second hyperspectral camera. A similar spectral difference is found between control and 5xFAD transgenic mice that accumulate Aβ in the brain and retina. These findings indicate that retinal hyperspectral imaging may predict brain Aβ load.

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