Edwin van Dellen1,2,3,4, Hanneke de Waal1, Wiesje M van der Flier1,5, Afina W Lemstra1, Arjen J C Slooter3, Lieke L Smits1, Elisabeth C W van Straaten2, Cornelis J Stam2, Philip Scheltens1. 1. Alzheimer Center and Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands. 2. Department of Clinical Neurophysiology and MEG Center, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands. 3. Department of Intensive Care Medicine, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands. 4. Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands. 5. Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands.
Abstract
OBJECTIVE: The aim of this study was to test whether disturbed EEG resting-state functional connectivity and network organization are a potential neurophysiological substrate of cognitive impairment in dementia with Lewy bodies. METHODS: EEG recordings were obtained in dementia with Lewy bodies patients, Alzheimer's disease patients and controls, matched for age and sex (N = 66 for each group; 14 [21%] female; mean age: 70 years). We analyzed functional connectivity of band-filtered EEG time series using the phase lag index. Functional brain network topology was analyzed with the minimum spanning tree. Mini-Mental State Examination, Trail Making Test A, and Visual Association Test were used as cognitive measures. RESULTS: Dementia with Lewy bodies patients showed lower connectivity strength in the alpha frequency band, compared to both controls and Alzheimer's disease patients (P < 0.001). Functional network topology in dementia with Lewy bodies patients was less efficient and contained less hubs (P < 0.01). Network characteristics in Alzheimer's disease patients were in between (but did not differ from) those of the other two groups. In dementia with Lewy bodies patients, lower alpha band phase lag index correlated with Visual Association Test scores and Trail Making Test scores (ρ = 0.33 and ρ = 0.31, respectively), whereas leaf fraction (a measure of 'network efficiency') correlated with Visual Association Test scores (ρ = 0.29) and Mini-Mental State Examination scores (ρ = 0.27). CONCLUSION: Functional networks of dementia with Lewy bodies patients are characterized by decreased connectivity strength and a loss of network efficiency and hubs. Severity of these disturbances is related to cognitive impairment, suggesting that network disturbances mediate between neuropathology and the clinical syndrome in dementia with Lewy bodies.
OBJECTIVE: The aim of this study was to test whether disturbed EEG resting-state functional connectivity and network organization are a potential neurophysiological substrate of cognitive impairment in dementia with Lewy bodies. METHODS: EEG recordings were obtained in dementia with Lewy bodiespatients, Alzheimer's diseasepatients and controls, matched for age and sex (N = 66 for each group; 14 [21%] female; mean age: 70 years). We analyzed functional connectivity of band-filtered EEG time series using the phase lag index. Functional brain network topology was analyzed with the minimum spanning tree. Mini-Mental State Examination, Trail Making Test A, and Visual Association Test were used as cognitive measures. RESULTS:Dementia with Lewy bodiespatients showed lower connectivity strength in the alpha frequency band, compared to both controls and Alzheimer's diseasepatients (P < 0.001). Functional network topology in dementia with Lewy bodiespatients was less efficient and contained less hubs (P < 0.01). Network characteristics in Alzheimer's diseasepatients were in between (but did not differ from) those of the other two groups. In dementia with Lewy bodiespatients, lower alpha band phase lag index correlated with Visual Association Test scores and Trail Making Test scores (ρ = 0.33 and ρ = 0.31, respectively), whereas leaf fraction (a measure of 'network efficiency') correlated with Visual Association Test scores (ρ = 0.29) and Mini-Mental State Examination scores (ρ = 0.27). CONCLUSION: Functional networks of dementia with Lewy bodiespatients are characterized by decreased connectivity strength and a loss of network efficiency and hubs. Severity of these disturbances is related to cognitive impairment, suggesting that network disturbances mediate between neuropathology and the clinical syndrome in dementia with Lewy bodies.
Authors: Meenakshi Dauwan; Jessica J van der Zande; Edwin van Dellen; Iris E C Sommer; Philip Scheltens; Afina W Lemstra; Cornelis J Stam Journal: Alzheimers Dement (Amst) Date: 2016-08-19
Authors: M Hassan; L Chaton; P Benquet; A Delval; C Leroy; L Plomhause; A J H Moonen; A A Duits; A F G Leentjens; V van Kranen-Mastenbroek; L Defebvre; P Derambure; F Wendling; K Dujardin Journal: Neuroimage Clin Date: 2017-03-06 Impact factor: 4.881
Authors: Luis R Peraza; Ruth Cromarty; Xenia Kobeleva; Michael J Firbank; Alison Killen; Sara Graziadio; Alan J Thomas; John T O'Brien; John-Paul Taylor Journal: Sci Rep Date: 2018-03-15 Impact factor: 4.379
Authors: Simone J T van Montfort; Edwin van Dellen; Aletta M R van den Bosch; Willem M Otte; Maya J L Schutte; Soo-Hee Choi; Tae-Sub Chung; Sunghyon Kyeong; Arjen J C Slooter; Jae-Jin Kim Journal: Neuroimage Clin Date: 2018-06-19 Impact factor: 4.881