FUNCTIONAL NEUROMARKERS OF COGNITIVE IMPAIRMENT IN VASCULAR DEMENTIA: A CASE STUDY

2020 ◽  
Vol 18 (3) ◽  
pp. 313-325
Author(s):  
Marzena Supińska ◽  
Jolanta Górla-Półrola ◽  
Ksenia Cielebąk ◽  
Izabela Herman-Sucharska ◽  
Juri D. Kropotov ◽  
...  

Early diagnosis and monitoring of disease progression in patients with Vascular Dementia (VaD) have become vital in clinical practice, as disease modifying treatments for VaD become available. The goal of our research was to study cognitive impairment in a patient at an early stage of VaD. We evaluated latencies of the P3 GO and NOGO components of event-related potentials (ERPs), elicited in cued GO/NOGO tasks, as potential neuromarkers of cognitive im- pairment, as suggested by previous research. The patient, a right-handed, 53-year-old male with a college edu- cation, suffered a transient ischemic attack (TIA) in 2011. During this attack, which lasted for a few minutes, he was confused and had trouble speaking, trouble seeing in both eyes, difficulty walking, problems with balance and coordination, and strange behavior. Se - ven years later, in 2018, he was assessed using the HBI methodol- ogy, which consisted of recording (1) a 19-channel EEG in resting state (with eyes open and eyes closed), and (2) a cued GO/NOGO task, and then comparing the results with EEG spectra and Event- Related Potentials (ERPs) data from normative and patient data - bases. The patient died in 2019. Post-mortem studies confirmed cortical microhaemorrhages neuropathological criteria for VaD. We did not found deposits of hyperphosphorylated tau (HPτ) and Aβ, which fulfil the neuropathological criteria for AD. The parietal-temporal-occipital EEG power was significantly higher in all conditions in this subject in comparison to healthy controls, indicating idling of the corresponding areas. The amplitude and la- tency of the P3 GO wave were found to be intact in the subject, in- dicating normal posterior cortical functioning in the cognitive task. The latency of the P3 GO wave was found to be significantly higher in the subject, indicating impairment of engagement operations. In a GO/NOGO task, ERPs provide a useful tool for assessment of brain functioning in clinical settings.

2009 ◽  
Vol 23 (4) ◽  
pp. 157-173 ◽  
Author(s):  
Robert J. Barry ◽  
Adam R. Clarke

Data are presented on EEG activity in typically developing controls, focusing on the traditional delta, theta, alpha, and beta bands through childhood, with some extensions into adolescence and adults. Both eyes-closed and eyes-open resting state data are discussed. These reflections of typical development provide a framework for illustrating EEG differences in people with attention deficit/hyperactivity disorder (AD/HD), and its main diagnostic types, from children to adults. Comorbidity effects in the EEG of children with AD/HD, particularly comorbid reading disabilities and conduct disorders, are also described. Some recent explorations of the links between arousal/activation and EEG activity may contribute to our understanding of the functional nature of brain oscillations in this context. Other aspects of oscillatory brain activity, coherence and event-related potentials, are also briefly discussed within this framework.


1996 ◽  
Vol 22 (3) ◽  
pp. 245-260 ◽  
Author(s):  
Mario Signorino ◽  
Enrico Brizioli ◽  
Loredana Amadio ◽  
Natascia Belardinelli ◽  
Eugenio Pucci ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Irina Chamine ◽  
Barry S. Oken

Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions.Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress.Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude.Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Lei Wang ◽  
Jiehui Zheng ◽  
Shenwei Huang ◽  
Haoye Sun

Our study aims to contrast the neural temporal features of early stage of decision making in the context of risk and ambiguity. In monetary gambles under ambiguous or risky conditions, 12 participants were asked to make a decision to bet or not, with the event-related potentials (ERPs) recorded meantime. The proportion of choosing to bet in ambiguous condition was significantly lower than that in risky condition. An ERP component identified as P300 was found. The P300 amplitude elicited in risky condition was significantly larger than that in ambiguous condition. The lower bet rate in ambiguous condition and the smaller P300 amplitude elicited by ambiguous stimuli revealed that people showed much more aversion in the ambiguous condition than in the risky condition. The ERP results may suggest that decision making under ambiguity occupies higher working memory and recalls more past experience while decision making under risk mainly mobilizes attentional resources to calculate current information. These findings extended the current understanding of underlying mechanism for early assessment stage of decision making and explored the difference between the decision making under risk and ambiguity.


Author(s):  
B.L. Brown ◽  
S.B. Hendrix ◽  
M. Cecchi ◽  
J.M. Scott ◽  
J.W. Silcox ◽  
...  

Event-related potentials (ERPs) are a physiological measure of cognitive function that have shown diagnostic and prognostic utility in Alzheimer’s disease (AD). In this study, we used a novel eigenvector-based technique to better understand brain electrophysiological differences between subjects with mild AD and healthy controls (HC). Using ERPs from 75 subjects with mild AD and 95 HC, we first calculated cognitive task eigenvectors within each subject from three conditions and then calculated second-order eigenvector components to compare the AD group to the HC group. A MANOVA of the three second-level components discriminated between AD and HC multivariately (Wilks’ lambda=.4297, p<0.0001, R2 = .5703), and also on each of the three components univariately (all 3 p-values<0.0001). The eigenvector-based technique used in this study accurately discriminated between the mild AD group and HC. As such, this analysis method adds to our understanding of the differences in ERP signal between AD and HC, and could provide a sensitive biomarker for diagnosis and monitoring of AD progression.


2016 ◽  
pp. 693-699
Author(s):  
Rene L. Utianski ◽  
John N. Caviness

Movement-related cortical potentials (MRCPs) are EEG potentials that occur with movement and are recorded using surface scalp electrodes. A technique termed “EEG-EMG back-averaging” is used to obtain MRCPs. The earliest recordable MRCP is the Bereitschaftspotential or readiness potential. Special EEG averaging techniques may also be used to study the cortical processes underlying cognition. Event-related potentials (ERPs) record the cortical activity evoked by a stimulus charged with cognitive significance. The P300 is the most commonly recorded ERP, elicited in an oddball technique of auditory stimulation; the subject is instructed to attend to a rare stimulus presented among a string of frequent stimuli. Only trials triggered by this rare event are averaged. The P300 may be the electrophysiological correlate of selected attention. The N400, another ERP, is assessed during semantic comprehension of language. The chapter discusses normal variants of MRCPs and ERPs, as well as disruptions secondary to neurological disease.


2019 ◽  
Vol 9 (5) ◽  
pp. 109 ◽  
Author(s):  
John F. Shelley-Tremblay ◽  
Joshua C. Eyer ◽  
Benjamin D. Hill

Symptom exaggeration and feigned cognitive impairment occur commonly in forensic and medicolegal evaluations. As a result, methods to detect feigned cognitive impairment are an indispensable component of neuropsychological assessments. This study reports the results of two neurophysiological experiments using a forced-choice recognition task built from the stimuli of the Word Memory Test and Medical Symptom Validity Test as well as a new linguistically informed stimulus set. Participant volunteers were instructed either to do their best or to feign cognitive impairment consistent with a mild traumatic brain injury while their brain activity was monitored using event-related potentials (ERP). Experiment 1 varied instructions across individuals, whereas Experiment 2 varied instructions within individuals. The target brain component was a positive deflection indicating stimulus recognition that occurs approximately 300 ms after exposure to a stimulus (i.e., the P300). Multimodal comparison (P300 amplitude to behavioral accuracy) allowed the detection of feigned cognitive impairment. Results indicate that, for correct responses, P300s were equivalent for the simulated malingering and good effort conditions. However, for incorrect responses, feigned impairment produced reliable but significantly reduced P300 amplitudes. Although the P300 is an automatic index of recognition—even when knowledge is hidden—its amplitude appears capable of modulation by feigning strategies. Implications of this finding are discussed for research and clinical applications.


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