Brain lesions that produce delta waves in the EEG

Gloor, P.; Ball, G.; Schaul, Neil

doi:10.1212/wnl.27.4.326

Cited by 431 publications

(249 citation statements)

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“…The present findings agree with previous studies in which subcortical damage in mild VaD patients were responsible for a large and widespread increase of theta source activity (Gloor et al, 1977;Coben et al, 1983). Of note, the increase of theta could be linked to the general slowing of the dominant frequency in VaD and this could explain why it is less evident in mild AD.…”

Section: Low Eeg Rhythms In Mild Dementiasupporting

confidence: 93%

Individual analysis of EEG frequency and band power in mild Alzheimer's disease

Moretti

Babiloni

Binetti

et al. 2004

Clinical Neurophysiology

337

251

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Objective: This EEG study investigates the role of the cholinergic system, cortico-cortical connections, and sub-cortical white matter on the relationship between individual EEG frequencies and their relative power bands.Methods: EEGs were recorded at rest in 30 normal elderly subjects (Nold), 60 mild Alzheimer disease (AD) and 20 vascular dementia (VaD) patients, comparable for Mini Mental State Evaluation scores . Individual EEG frequencies were indexed by the theta/alpha transition frequency (TF) and by the individual alpha frequency (IAF) with power peak in the extended alpha range (5 -14 Hz). Relative power was separately computed for delta, theta, alpha1, alpha2, and alpha3 bands, on the basis of the TF and IAF.Results: Using normal subjects as a reference, VaD patients showed 'slowing' of alpha frequency (TF-IAF) and lower alpha2 power; Mild AD patients showed lower alpha2 and alpha3 power; delta power was higher in both AD and VaD patients; Theta power was higher only in VaD patients.Conclusions: Individual analysis of the alpha frequency and power can discriminate mild AD from VaD and normal elderly subjects.Significance: This analysis may probe pathophysiological mechanisms causing AD and VaD.

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Section: Low Eeg Rhythms In Mild Dementiasupporting

confidence: 93%

Individual analysis of EEG frequency and band power in mild Alzheimer's disease

Moretti

Babiloni

Binetti

et al. 2004

Clinical Neurophysiology

337

251

View full text Add to dashboard Cite

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“…In fact, a theoretical model considering a mean speed propagation in white matter fibers of 7.5 m/s (together with other parameters) is associated with a fundamental mode frequency of 9 Hz (Nunez, 1995;Nunez and Srinivasan, 2006), that is, the typical mode of scalp-recorded EEG. It is to be noted that a correlation between white matter damage and widespread slowing of EEG rhythmicity was found in other studies, following the presence of cognitive decline (d'Onofrio et al, 1996;Szelies et al, 1992Szelies et al, , 1999, multiple sclerosis (Leocani et al, 2000), or cerebral tumors (Gloor et al, 1977;Goldensohn, 1979). In the present study, we found neither impact of vascular damage on the IAF, nor significant correlation between CV damage score and IAF.…”

Section: Eeg Frequency Indices Of a Rhythms And CV Damagementioning

confidence: 64%

Vascular damage and EEG markers in subjects with mild cognitive impairment

Moretti

Miniussi

Frisoni

et al. 2007

Clinical Neurophysiology

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Objective: We evaluated the changes induced by cerebrovascular (CV) damage on brain rhythmicity recorded by electroencephalography (EEG) in a cohort of subjects with mild cognitive impairment (MCI). Methods: We enrolled 99 MCI subjects (Mini-Mental State Examination [MMSE] mean score 26.6). All subjects underwent EEG recording and magnetic resonance imaging (MRI). EEGs were recorded at rest. Individual EEG frequencies were indexed by the h/a transition frequency (TF) and by the individual a frequency (IAF) with power peak in the extended a range (5-14 Hz). Relative power was separately computed for d, h, a1, a2, and a3 frequency bands on the basis of the TF and IAF values. Subsequently, we divided the cohort in four sub-groups based on subcortical CV damage as scored by the age-related white matter changes scale (ARWMC). Results: CV damage was associated with 'slowing' of TF proportional to its severity. In the spectral bandpower the severity of vascular damage was associated with increased d power and decreased a2 power. No association of vascular damage was observed with IAF and a3 power. Moreover, the h/a1 ratio could be a reliable index for the estimation of the individual extent of CV damage. Conclusions: EEG analysis may show physiological markers sensitive to CV damage. The appropriate use of this EEG index may help the differential diagnosis of different forms of cognitive decline, namely primary degenerative and secondary to CV damage. Significance: The EEG neurophysiological approach, together with anatomical features from imaging, could be helpful in the understanding of the functional substrate of dementing disorders.

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“…Neurophysiological studies in animals have established a solid connection between pathological delta-wave (1-4 Hz) generation in GM and axonal injuries in WM. Gloor et al showed that polymorphic delta-band slow-waves produced by (white matter) WM axonal lesions in the cat were localized to the GM area of cortex overlying the lesion Gloor et al, 1977). They also found that pathological delta-waves can be induced by the administration of atropine in the WM (Schaul et al, 1978).…”

Section: Clinicalmentioning

confidence: 99%

The role of biomarkers and MEG-based imaging markers in the diagnosis of post-traumatic stress disorder and blast-induced mild traumatic brain injury

Huang

Risling

Baker

2016

Psychoneuroendocrinology

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SummaryBackground: Pervasive use of improvised explosive devices (IEDs), rocket-propelled grenades, and land mines in the recent conflicts in Iraq and Afghanistan has brought traumatic brain injury (TBI) and its impact on health outcomes into public awareness. Blast injuries have been deemed signature wounds of these wars. War-related TBI is not new, having become prevalent during WWI and remaining medically relevant in WWII and beyond. Medicine's past attempts to accurately diagnose and disentangle the pathophysiology of war-related TBI parallels current lines of inquiry and highlights limitations in methodology and attribution of symptom etiology, be it organic, psychological, or behavioral. New approaches and biomarkers are needed. Preclinical: Serological biomarkers and biomarkers of injury obtained with imaging techniques represent cornerstones in the translation between experimental data and clinical observations. Experimental models for blast related TBI and PTSD can generate critical data on injury threshold, for example for white matter injury from acceleration. Carefully verified and validated models can be evaluated with gene expression arrays and proteomics to identify new candidates for serological biomarkers. Such models can also be analyzed with diffusion MRI and microscopy in order to identify criteria for detection of diffuse white matter injuries, such as DAI (diffuse axonal injury). The experimental models can also be analyzed with focus on injury outcome in brain stem regions, such as locus coeruleus or nucleus raphe magnus that can be involved in response to anxiety changes. * Corresponding author at: UCSD Radiology Imaging Laboratory, San Diego, CA 92121, USA. Tel.: +1 858 534 1254; fax: +1 8585346046. E-mail address: mxhuang@ucsd.edu (M. Huang). Clinical: Mild (and some moderate) TBI can be difficult to diagnose because the injuries are often not detectable on conventional MRI or CT. There is accumulating evidence that injured brain tissues in TBI patients generate abnormal low-frequency magnetic activity (ALFMA, peaked at 1-4 Hz) that can be measured and localized by magnetoencephalography (MEG). MEG imaging detects TBI abnormalities at the rates of 87% for the mild TBI, group (blast-induced plus non-blast causes) and 100% for the moderate group. Among the mild TBI patients, the rates of abnormalities are 96% and 77% for the blast and non-blast TBI groups, respectively. There is emerging evidence based on fMRI and MEG studies showing hyper-activity in the amygdala and hypo-activity in prefrontal cortex in individuals with PTSD. MEG signal may serve as a sensitive imaging marker for mTBI, distinguishable from abnormalities generated in association with PTSD. More work is needed to fully describe physiological mechanisms of post-concussive symptoms.Published by Elsevier Ltd. BackgroundBlast injuries are deemed the signature wounds of the first wars (Afghanistan and Iraq) of the 21st century (Lancet, 2007;Galarneau et al., 2008). According to a recent U.S. Department Veterans Affairs (DVA) ...

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Brain lesions that produce delta waves in the EEG

Cited by 431 publications

References 0 publications

Individual analysis of EEG frequency and band power in mild Alzheimer's disease

Individual analysis of EEG frequency and band power in mild Alzheimer's disease

Vascular damage and EEG markers in subjects with mild cognitive impairment

The role of biomarkers and MEG-based imaging markers in the diagnosis of post-traumatic stress disorder and blast-induced mild traumatic brain injury

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