3 research outputs found
EEG Markers of Dementia with Lewy Bodies:A Multicenter Cohort Study
Quantitative EEG (QEEG) has demonstrated good discriminative capacity for dementia with Lewy bodies (DLB) diagnosis as compared to Alzheimer's disease (AD) with a predictive value of 100 in a single cohort study. EEG in DLB was characterized by a dominant frequency (DF) in pre-alpha (5.5-7.5Hz), theta, or delta bands and DF variability (DFV) >1.2Hz, frequency prevalence (FP) pre-alpha in >40 and FP alpha in <32 of the epochs. To validate the aforementioned QEEG findings in independent cohorts of clinically diagnosed DLB versus AD patients, we analyzed EEG traces of 79 DLB and 133 AD patients (MMSE >20) collected from four European Centers. EEG traces from 19 scalp derivations were acquired as at least 10min continuous signals and epoched in off-setting as series of 2-second-long epochs, subsequently processed by Fast Fourier Transform (frequency resolution 0.5Hz). DLB patients showed EEG specific abnormalities in posterior derivations characterized by DF <8Hz FP pre-alpha >50, FP alpha <25. DFV was >0.5Hz. AD patients displayed stable alpha DF, DFV <0.5Hz, FP pre-alpha <30, and FP alpha >55. DLB and AD differed for DF (p<10-6), DFV (p<0.05), FP pre-alpha (p<10-12) and FP alpha (p<10-12). Discriminant analysis detected specific cut-offs for every EEG mathematical descriptor; DF=8, DFV=2.2Hz, FP pre-alpha=33, FP alpha=41 for posterior derivations. If at least one of the cut-off values was met, the percentage of DLB and AD patients correctly classified was 90 and 64, respectively. The findings in this multicenter study support the validity of QEEG analysis as a tool for diagnosis in DLB patients
Different Abnormalities of Cortical Neural Synchronization Mechanisms in Patients with Mild Cognitive Impairment due to Alzheimer's and Chronic Kidney Diseases: An EEG Study
This study tested whether resting state alpha rhythms (8-13 Hz) may characterize mild cognitive impairment due to Alzheimer's disease (ADMCI) compared with MCI due to chronic kidney disease (CKDMCI). Clinical and resting state eyes-closed electroencephalographic (rsEEG) rhythms from 40 ADMCI, 29 CKDMCI, and 45 cognitively normal elderly (Nold) subjects were available in a national archive. Age, gender, and education were matched in the three groups, and Mini-Mental State Evaluation (MMSE) score was paired in the ADMCI and CKDMCI groups. Delta (<4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz), and gamma (30-40 Hz) cortical sources were estimated by eLORETA freeware and classified across individuals by area under the receiver operating characteristic curve (AUROCC). Compared with Nold group, posterior alpha 1 source activities were more reduced in ADMCI than CKDMCI group. In contrast, widespread delta source activities were greater in CKDMCI than ADMCI group. These source activities correlated with the MMSE score and correctly classified between Nold and all MCI individuals (AUROCC = 0.8-0.85) and between ADMCI and CKDMCI subjects (AUROCC = 0.75). These results suggest that early AD affects cortical neural synchronization at alpha frequencies underpinning brain arousal and low vigilance in the quiet wakefulness. In contrast, CKD may principally affect cortical neural synchronization at the delta frequencies. Future prospective cross-validation studies will have to test these candidate rsEEG markers for clinical applications and drug discovery
Proceedings of the fourth Resilience Engineering Symposium
These proceedings document the various presentations at the Fourth Resilience Engineering Symposium held on June 8-10, 2011, in Sophia-Antipolis, France. The Symposium gathered participants from five continents and provided them with a forum to exchange experiences and problems, and to learn about Resilience Engineering from the latest scientific achievements to recent practical applications. The First Resilience Engineering Symposium was held in Söderköping, Sweden, on October 25-29 2004. The Second Resilience Engineering Symposium was held in Juan-les-Pins, France, on November 8-10 2006, The Third Resilience Engineering Symposium was held in Juan-les-Pins, France, on October 28-30 2008. Since the first Symposium, resilience engineering has fast become recognised as a valuable complement to the established approaches to safety. Both industry and academia have recognised that resilience engineering offers valuable conceptual and practical basis that can be used to attack the problems of interconnectedness and intractability of complex socio-technical systems. The concepts and principles of resilience engineering have been tested and refined by applications in such fields as air traffic management, offshore production, patient safety, and commercial fishing. Continued work has also made it clear that resilience is neither limited to handling threats and disturbances, nor confined to situations where something can go wrong. Today, resilience is understood as the intrinsic ability of a system to adjust its functioning prior to, during, or following changes and disturbances, so that it can sustain required operations under both expected and unexpected conditions. This definition emphasizes the ability to continue functioning, rather than simply to react and recover from disturbances and the ability to deal with diverse conditions of functioning, expected as well as unexpected. For anyone who is interested in learning more about Resilience Engineering, the books published in the Ashgate Studies in Resilience Engineering provide an excellent starting point. Another sign that Resilience Engineering is coming of age is the establishment of the Resilience Engineering Association. The goal of this association is to provide a forum for coordination and exchange of experiences, by bringing together researchers and professionals working in the Resilience Engineering domain and organisations applying or willing to apply Resilience Engineering principles in their operations. The Resilience Engineering Association held its first General Assembly during the Fourth Symposium, and will in the future play an active role in the organisation of symposia and other activities related to Resilience Engineering