Electroencephalographic Coherence in Alzheimer's Disease: Comparisons with a Control Group and Population Norms

Knott, Verner; Mohr, Erich; Mahoney, Colleen; Ilivitsky, Vadim

doi:10.1177/089198870001300101

Cited by 109 publications

(105 citation statements)

References 39 publications

(10 reference statements)

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“…A decrease of resting state functional connectivity in Alzheimer's disease patients in the alpha and often also in the beta band has been reported in many EEG and MEG studies (Leuchter et al, 1992;Besthorn et al, 1994;Dunkin et al, 1994;Jelic et al, 1996;Locatelli et al, 1998;Knott et al, 2000;Stevens et al, 2001;Adler et al, 2003;Hogan et al, 2003;Jiang 2005;Koenig et al, 2005;Pogarell et al, 2005). However, a major point of criticism is that such studies were done on the raw EEG and MEG time series.…”

Section: Volume Conductionmentioning

confidence: 97%

“…It has even been suggested that Alzheimer's disease can be viewed as a disconnection syndrome (Delbeuck et al, 2003). Support for this concept comes from a number of EEG and magneto-encephalography (MEG) studies using conventional coherence as a measure of functional connectivity (Leuchter et al, 1992;Besthorn et al, 1994;Dunkin et al, 1994;Jelic et al, 1996;Locatelli et al, 1998;Berendse et al, 2000;Knott et al, 2000;Stevens et al, 2001;Adler et al, 2003;Hogan et al, 2003;Jiang 2005;Koenig et al, 2005;Pogarell et al, 2005). In most of these studies a consistent decrease of coherence in the alpha and beta band was reported, whereas results for other bands were more variable.…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

Graph theoretical analysis of magnetoencephalographic functional connectivity in Alzheimer's disease

Stam¹,

Haan²,

Daffertshofer³

et al. 2008

Brain

837

704

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In this study we examined changes in the large-scale structure of resting-state brain networks in patients with Alzheimer's disease compared with non-demented controls, using concepts from graph theory. Magneto-encephalograms (MEG) were recorded in 18 Alzheimer's disease patients and 18 non-demented control subjects in a no-task, eyes-closed condition. For the main frequency bands, synchronization between all pairs of MEG channels was assessed using a phase lag index (PLI, a synchronization measure insensitive to volume conduction). PLI-weighted connectivity networks were calculated, and characterized by a mean clustering coefficient and path length. Alzheimer's disease patients showed a decrease of mean PLI in the lower alpha and beta band. In the lower alpha band, the clustering coefficient and path length were both decreased in Alzheimer's disease patients. Network changes in the lower alpha band were better explained by a 'Targeted Attack' model than by a 'Random Failure' model. Thus, Alzheimer's disease patients display a loss of resting-state functional connectivity in lower alpha and beta bands even when a measure insensitive to volume conduction effects is used. Moreover, the large-scale structure of lower alpha band functional networks in Alzheimer's disease is more random. The modelling results suggest that highly connected neural network 'hubs' may be especially at risk in Alzheimer's disease.

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Section: Volume Conductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 93%

Graph theoretical analysis of magnetoencephalographic functional connectivity in Alzheimer's disease

Stam¹,

Haan²,

Daffertshofer³

et al. 2008

Brain

837

704

View full text Add to dashboard Cite

show abstract

“…They also found that 22% of normal controls had a BIS XP < 93; demonstrating wide interindividual variability and limiting its potential diagnostic use clinically. The quantitative EEG has been used as a research tool in the diagnosis of dementia; however, it has yet to demonstrate proven diagnostic utility [15].…”

Section: Discussionmentioning

confidence: 99%

BIS and Entropy in the elderly

et al. 2007

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SummaryThe interaction of many poorly defined, physiological, pharmacological, and pathological factors make titration of general anaesthesia in the elderly difficult. There may be a potential clinical benefit using the processed electroencephalogram (EEG) to monitor hypnotic level in this population. We prospectively studied 16 patients aged over 65 years having hip fractures repaired under general anaesthesia by experienced anaesthetists blinded to Bispectral Index (BIS XP ) and Entropy values. Pre-induction EEG indices did not correlate with age or mini-mental state examination (MMSE). During maintenance of anaesthesia, BIS XP and Response Entropy (RE) values were within the recommended range of 40-60, 45% and 32% of the total time, respectively. BIS XP and Response Entropy (RE) values were above 60 for 11% and 13% of the total time, respectively, and below 40 for 44% and 55% of the total time, respectively. BIS XP correlated well with RE in 12 patients, but in the other four patients there was a difference of more than 20 points between BIS XP and RE.

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“…In comparison with normal controls, there is increased activity in the theta band in subjects with Alzheimer's disease (AD), which is accompanied by an increase in delta activity and decreases in the alpha and beta bands 4 . In studies on coherence in AD, the most consistent finding has been a reduction in coherence in the alpha band [5][6][7] . There is still insufficient scientific evidence of the diagnostic utility of qEEG to establish this method for the initial evaluation of subjects with cognitive impairment in routine clinical practice 8 .…”

mentioning

confidence: 97%

Alzheimer's disease: relationship between cognitive aspects and power and coherence EEG measures

Fonseca

Tedrus

Prandi³

et al. 2011

Arq. Neuro-Psiquiatr.

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Objective: To evaluate the relationship between specific cognitive aspects and quantitative EEG measures, in patients with mild or moderate Alzheimer's disease (AD). Method: Thirty-eight AD patients and 31 controls were assessed by CERAD neuropsychological battery (Consortium to Establish a Registry for AD) and the electroencephalogram (EEG). The absolute power and coherences EEG measures were calculated at rest. The correlations between the cognitive variables and the EEG were evaluated. Results: In the AD group there were significant correlations between different coherence EEG measures and Mini-Mental State Examination, verbal fluency, modified Boston naming, word list memory with repetition, word list recall and recognition, and constructional praxis (p<0.01). These correlations were all negative for the delta and theta bands and positive for alpha and beta. There were no correlations between cognitive aspects and absolute EEG power. Conclusion: The coherence EEG measures reflect different forms in the relationship between regions related to various cognitive dysfunctions. Key words: dementia, cognition, Alzheimer's disease, electroencephalography. Doença de Alzheimer: relação entre aspectos cognitivos e medidas de potência e coerência no eletrencefalograma RESUMO Objetivo: Avaliar as relações entre aspectos cognitivos específicos e medidas quantitativas do EEG em pacientes com doença de Alzheimer (DA) leve e moderado. Método: Trinta e oito pacientes com DA e 31 controles foram avaliados com a bateria neuropsicológica CERAD (Consortium to Establish a Registry for AD) e o eletroencefalograma. Foram realizadas medidas de potência absoluta e coerência do EEG, durante repouso, e avaliadas suas relações com variáveis do CERAD. Resultados: No grupo DA houve correlações significativas entre diferentes medidas de coerência e o mini-exame do estado mental, fluência verbal, teste de nomeação de Boston modificado, memória de lista de palavras com repetição, recordação e reconhecimento de lista de palavras e praxia construtiva (p<0,01). Essas correlações foram negativas para as faixas delta e teta e positivas para alfa e beta. Conclusão: As medidas de coerência do EEG em repouso refletem diferentes formas de organização nas relações entre regiões, relacionadas a várias disfunções cognitivas. Palavras-Chave: demência, cognição, doença de Alzheimer, eletroencefalograma. Correspondence

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Electroencephalographic Coherence in Alzheimer's Disease: Comparisons with a Control Group and Population Norms

Cited by 109 publications

References 39 publications

Graph theoretical analysis of magnetoencephalographic functional connectivity in Alzheimer's disease

Graph theoretical analysis of magnetoencephalographic functional connectivity in Alzheimer's disease

BIS and Entropy in the elderly

Alzheimer's disease: relationship between cognitive aspects and power and coherence EEG measures

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