Neurophysiology and SPECT cerebral blood flow patterns in dementia

Sloan, Eileen P.; Fenton, George W.; Kennedy, Norman; MacLennan, J. M.

doi:10.1016/0013-4694(94)90066-3

Cited by 39 publications

(35 citation statements)

References 17 publications

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“…Decreases in coherence in AD have been reported mostly in alpha (Leuchter et al 1992;Besthorn et al 1994;Sloan et al 1994;Jelic et al 1997) but also in beta bands (Leuchter et al 1992;Besthorn et al 1994), similar to those seen following scopolamine administration in normal subjects (Sloan et al 1992). Decreases have been reported at least in one study to be more significant for intrahemispheric than for interhemispheric coherence (Calderon et al 1997), with greatest decreases noted in long corticocortical fiber tracts (Leuchter et al 1992).…”

Section: Discussionmentioning

confidence: 86%

Changes in electrocortical power and coherence in response to the selective cholinergic immunotoxin 192 IgG-saporin

Holschneider

Waite

Leuchter

et al. 1999

Experimental Brain Research

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Changes in brain electrical activity in response to cholinergic agonists, antagonists, or excitotoxic lesions of the basal forebrain may not be reflective entirely of changes in cholinergic tone, in so far as these interventions also involve noncholinergic neurons. We examined electrocortical activity in rats following bilateral intracerebroventricular administration of 192 IgG-saporin (1.8 μg/ventricle), a selective cholinergic immunotoxin directed to the low-affinity nerve growth factor receptor p75. The immunotoxin resulted in extensive loss of choline acetyl transferase (ChAT) activity in neocortex (80%-84%) and hippocampus (93%), with relative sparing of entorhinalpiriform cortex (42%) and amygdala (28%). Electrocortical activity demonstrated modest increases in 1-to 4-Hz power, decreases in 20-to 44-Hz power, and decreases in 4-to 8-Hz intraand interhemispheric coherence. Rhythmic slow activity (RSA) occurred robustly in toxin-treated animals during voluntary movement and in response to physostigmine, with no significant differences seen in power and peak frequency in comparison with controls. Physostigmine significantly increased intrahemispheric coherence in lesioned and intact animals, with minor increases seen in interhemispheric coherence. Our study suggests that: (1) electrocortical changes in response to selective cholinergic deafferentation are more modest than those previously reported following excitotoxic lesions; (2) changes in cholinergic tone affect primarily brain electrical transmission within, in contrast to between hemispheres; and (3) a substantial

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Section: Discussionmentioning

confidence: 86%

Changes in electrocortical power and coherence in response to the selective cholinergic immunotoxin 192 IgG-saporin

Holschneider

Waite

Leuchter

et al. 1999

Experimental Brain Research

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“…are the impulse responses of elliptic bandpass filters used to separate delta (0.1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), and gamma (30-100 Hz) bands [44]. The temporal amplitude envelope of each of the five subband EEG signals is then computed by means of a Hilbert transform H{·} (the interested reader is referred to [45] and references therein for more details).…”

Section: Spectro-temporal Eeg Amplitude Modulation Analysismentioning

confidence: 99%

“…For the purpose of AD diagnosis, two branches of EEG signal analysis have emerged: spectral and nonlinear dynamics [5]. Pioneering spectral analysis studies showed that AD patients presented increased activity in the delta (0.1-4 Hz) and theta (4-8 Hz) frequency bands, as well as decreased activity in the alpha (8)(9)(10)(11)(12) and beta (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) Hz) bands [6][7][8][9][10][11], thus suggesting a slowing of the EEG signal. Moreover, reduced spectral coherence between the two hemispheres was shown between the alpha and beta frequency bands [12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

EEG amplitude modulation analysis for semi-automated diagnosis of Alzheimer’s disease

Falk

Fraga

Trambaiolli

et al. 2012

EURASIP J. Adv. Signal Process.

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Recent experimental evidence has suggested a neuromodulatory deficit in Alzheimer's disease (AD). In this paper, we present a new electroencephalogram (EEG) based metric to quantitatively characterize neuromodulatory activity. More specifically, the short-term EEG amplitude modulation rate-of-change (i.e., modulation frequency) is computed for five EEG subband signals. To test the performance of the proposed metric, a classification task was performed on a database of 32 participants partitioned into three groups of approximately equal size: healthy controls, patients diagnosed with mild AD, and those with moderate-to-severe AD. To gauge the benefits of the proposed metric, performance results were compared with those obtained using EEG spectral peak parameters which were recently shown to outperform other conventional EEG measures. Using a simple feature selection algorithm based on area-under-the-curve maximization and a support vector machine classifier, the proposed parameters resulted in accuracy gains, relative to spectral peak parameters, of 21.3% when discriminating between the three groups and by 50% when mild and moderate-to-severe groups were merged into one. The preliminary findings reported herein provide promising insights that automated tools may be developed to assist physicians in very early diagnosis of AD as well as provide researchers with a tool to automatically characterize cross-frequency interactions and their changes with disease.

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“…SPECT imaging in AD has utilized cerebral perfusion tracers almost exclusively (30)(31)(32)(33). Results obtained using these tracers have generally paralleled the findings seen with PET.…”

Section: Recent Developments In Alzheimer's Diseasementioning

confidence: 51%

Recent Developments in Alzheimer’s Disease

Cras¹

2001

Acta Clinica Belgica

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Neurophysiology and SPECT cerebral blood flow patterns in dementia

Cited by 39 publications

References 17 publications

Changes in electrocortical power and coherence in response to the selective cholinergic immunotoxin 192 IgG-saporin

Changes in electrocortical power and coherence in response to the selective cholinergic immunotoxin 192 IgG-saporin

EEG amplitude modulation analysis for semi-automated diagnosis of Alzheimer’s disease

Recent Developments in Alzheimer’s Disease

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