A method for diagnosis support of mild cognitive impairment through EEG rhythms source location during working memory tasks

2021 ◽  
Vol 66 ◽  
pp. 102499
Author(s):  
Rodrigo San-Martin ◽  
Erin Johns ◽  
Godofredo Quispe Mamani ◽  
Guilherme Tavares ◽  
Natalie A. Phillips ◽  
...  
2021 ◽  
Vol 82 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Sheina Emrani ◽  
Melissa Lamar ◽  
Catherine Price ◽  
Satya Baliga ◽  
Victor Wasserman ◽  
...  

Background: The model of executive attention proposes that temporal organization, i.e., the time necessary to bring novel tasks to fruition is an important construct that modulates executive control. Subordinate to temporal organization are the constructs of working memory, preparatory set, and inhibitory control. Objective: The current research operationally-defined the constructs underlying the theory of executive attention using intra-component latencies (i.e., reaction times) from a 5-span backward digit test from patients with suspected mild cognitive impairment (MCI). Methods: An iPad-version of the Backward Digit Span Test (BDT) was administered to memory clinic patients. Patients with (n = 22) and without (n = 36) MCI were classified. Outcome variables included intra-component latencies for all correct 5-span serial order responses. Results: Average total time did not differ. A significant 2-group by 5-serial order latency interaction revealed the existence of distinct time epochs. Non-MCI patients produced slower latencies on initial (position 2-working memory/preparatory set) and latter (position 4-inhibitory control) correct serial order responses. By contrast, patients with MCI produced a slower latency for middle serial order responses (i.e., position 3-preparatory set). No group differences were obtained for incorrect 5-span test trials. Conclusion: The analysis of 5-span BDT serial order latencies found distinct epochs regarding how time was allocated in the context of successful test performance. Intra-component latencies obtained from tests assessing mental re-ordering may constitute useful neurocognitive biomarkers for emergent neurodegenerative illness.


2020 ◽  
pp. 1-11
Author(s):  
Yang Jiang ◽  
Juan Li ◽  
Frederick A. Schmitt ◽  
Gregory A. Jicha ◽  
Nancy B. Munro ◽  
...  

Background: Early prognosis of high-risk older adults for amnestic mild cognitive impairment (aMCI), using noninvasive and sensitive neuromarkers, is key for early prevention of Alzheimer’s disease. We have developed individualized measures in electrophysiological brain signals during working memory that distinguish patients with aMCI from age-matched cognitively intact older individuals. Objective: Here we test longitudinally the prognosis of the baseline neuromarkers for aMCI risk. We hypothesized that the older individuals diagnosed with incident aMCI already have aMCI-like brain signatures years before diagnosis. Methods: Electroencephalogram (EEG) and memory performance were recorded during a working memory task at baseline. The individualized baseline neuromarkers, annual cognitive status, and longitudinal changes in memory recall scores up to 10 years were analyzed. Results: Seven of the 19 cognitively normal older adults were diagnosed with incident aMCI for a median 5.2 years later. The seven converters’ frontal brainwaves were statistically identical to those patients with diagnosed aMCI (n = 14) at baseline. Importantly, the converters’ baseline memory-related brainwaves (reduced mean frontal responses to memory targets) were significantly different from those who remained normal. Furthermore, differentiation pattern of left frontal memory-related responses (targets versus nontargets) was associated with an increased risk hazard of aMCI (HR = 1.47, 95% CI 1.03, 2.08). Conclusion: The memory-related neuromarkers detect MCI-like brain signatures about five years before diagnosis. The individualized frontal neuromarkers index increased MCI risk at baseline. These noninvasive neuromarkers during our Bluegrass memory task have great potential to be used repeatedly for individualized prognosis of MCI risk and progression before clinical diagnosis.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Anna-Mariya Kirova ◽  
Rebecca B. Bays ◽  
Sarita Lagalwar

Alzheimer’s disease (AD) is a progressive neurodegenerative disease marked by deficits in episodic memory, working memory (WM), and executive function. Examples of executive dysfunction in AD include poor selective and divided attention, failed inhibition of interfering stimuli, and poor manipulation skills. Although episodic deficits during disease progression have been widely studied and are the benchmark of a probable AD diagnosis, more recent research has investigated WM and executive function decline during mild cognitive impairment (MCI), also referred to as the preclinical stage of AD. MCI is a critical period during which cognitive restructuring and neuroplasticity such as compensation still occur; therefore, cognitive therapies could have a beneficial effect on decreasing the likelihood of AD progression during MCI. Monitoring performance on working memory and executive function tasks to track cognitive function may signal progression from normal cognition to MCI to AD. The present review tracks WM decline through normal aging, MCI, and AD to highlight the behavioral and neurological differences that distinguish these three stages in an effort to guide future research on MCI diagnosis, cognitive therapy, and AD prevention.


2020 ◽  
Vol 77 (2) ◽  
pp. 715-732
Author(s):  
Eleni Poptsi ◽  
Despina Moraitou ◽  
Emmanouil Tsardoulias ◽  
Andreas L. Symeonidisd ◽  
Magda Tsolaki

Background: The early diagnosis of neurocognitive disorders before the symptoms’ onset is the ultimate goal of the scientific community. REMEDES for Alzheimer (R4Alz) is a battery, designed for assessing cognitive control abilities in people with minor and major neurocognitive disorders. Objective: To investigate whether the R4Alz battery’s tasks differentiate subjective cognitive decline (SCD) from cognitively healthy adults (CHA) and mild cognitive impairment (MCI). Methods: The R4Alz battery was administered to 175 Greek adults, categorized in five groups a) healthy young adults (HYA; n = 42), b) healthy middle-aged adults (HMaA; n = 33), c) healthy older adults (HOA; n = 14), d) community-dwelling older adults with SCD (n = 34), and e) people with MCI (n = 52). Results: Between the seven R4Alz subtasks, four showcased the best results for differentiating HOA from SCD: the working memory updating (WMCUT-S3), the inhibition and switching subtask (ICT/RST-S1&S2), the failure sets (FS) of the ICT/RST-S1&S2, and the cognitive flexibility subtask (ICT/RST-S3). The total score of the four R4Alz subtasks (R4AlzTot4) leads to an excellent discrimination among SCD and healthy adulthood, and to fare discrimination among SCD and MCI. Conclusion: The R4Alz battery is a novel approach regarding the neuropsychological assessment of people with SCD, since it can very well assist toward discriminating SCD from HOA. The R4Alz is able to measure decline of specific cognitive control abilities - namely of working memory updating, and complex executive functions - which seem to be the neuropsychological substrate of cognitive complaints in community dwelling adults of advancing age.


2019 ◽  
Vol 19 (1) ◽  
pp. 8-19
Author(s):  
Louise Hickman ◽  
Caleb Ferguson ◽  
Patricia M Davidson ◽  
Sabine Allida ◽  
Sally Inglis ◽  
...  

Background: The purpose of this systematic review was to (a) examine the effects of interventions delivered by a heart failure professional for mild cognitive impairment and dementia on cognitive function, memory, working memory, instrumental activities of daily living, heart failure knowledge, self-care, quality of life and depression; and (b) identify the successful elements of these strategies for heart failure patients with mild cognitive impairment or dementia. Methods and results: During March 2018, an electronic search of databases including CINAHL, MEDLINE, EMBASE and PsycINFO was conducted. All randomised controlled trials, which examined an intervention strategy to help heart failure patients with mild cognitive impairment or dementia cope with self-care, were included. An initial search yielded 1622 citations, six studies were included ( N= 595 participants, mean age 68 years). There were no significant improvements in cognitive function and depression. However, significant improvements were seen in memory ( p=0.015), working memory ( p=0.029) and instrumental activities of daily living ( p=0.006). Nurse led interventions improved the patient’s heart failure knowledge ( p=0.001), self-care ( p<0.05) and quality of life ( p=0.029). Key elements of these interventions include brain exercises, for example, syllable stacks, individualised assessment and customised education, personalised self-care schedule development, interactive problem-solving training on scenarios and association techniques to prompt self-care activities. Conclusions: Modest evidence for nurse led interventions among heart failure patients with mild cognitive impairment or dementia was identified. These results must be interpreted with caution in light of the limited number of available included studies.


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