scholarly journals Enhanced Auditory Steady-State Response Using an Optimized Chirp Stimulus-Evoked Paradigm

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 748
Author(s):  
Xiaoya Liu ◽  
Shuang Liu ◽  
Dongyue Guo ◽  
Yue Sheng ◽  
Yufeng Ke ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Practice ◽  
Steady State ◽  
Affective Disorder ◽  
Healthy Subjects ◽  
Signal To Noise Ratio ◽  
Mental Diseases ◽  
40 Hz

Objectives: It has been reported recently that gamma measures of the electroencephalogram (EEG) might provide information about the candidate biomarker of mental diseases like schizophrenia, Alzheimer’s disease, affective disorder and so on, but as we know it is a difficult issue to induce visual and tactile evoked responses at high frequencies. Although a high-frequency response evoked by auditory senses is achievable, the quality of the recording response is not ideal, such as relatively low signal-to-noise ratio (SNR). Recently, auditory steady-state responses (ASSRs) play an essential role in the field of basic auditory studies and clinical uses. However, how to improve the quality of ASSRs is still a challenge which researchers have been working on. This study aims at designing a more comfortable and suitable evoked paradigm and then enhancing the quality of the ASSRs in healthy subjects so as to further apply it in clinical practice. Methods: Chirp and click stimuli with 40 Hz and 60 Hz were employed to evoke the gamma-ASSR respectively, and the sound adjusted to 45 dB sound pressure level (SPL). Twenty healthy subjects with normal-hearing participated, and 64-channel EEGs were simultaneously recorded during the experiment. Event-related spectral perturbation (ERSP) and SNR of the ASSRs were measured and analyzed to verify the feasibility and adaptability of the proposed evoked paradigm. Results: The results showed that the evoked paradigm proposed in this study could enhance ASSRs with strong feasibility and adaptability. 1) ASSR waves in time domain indicated that 40 Hz stimuli could significantly induce larger peak-to-peak values of ASSRs compared to 60 Hz stimuli (p < 0.01**); ERSP showed that obvious ASSRs were obtained at each lead for both 40 Hz and 60 Hz, as well as the click and chirp stimuli. 2) The SNR of the ASSRs were –3.23 ± 1.68, –2.44 ± 2.90, –4.66 ± 2.09, and –3.53 ± 3.49 respectively for 40 Hz click, 40 Hz chirp, 60 Hz click and 60 Hz chirp, indicating the chirp stimuli could induce significantly better ASSR than the click, and 40 Hz ASSRs had the higher SNR than 60 Hz (p < 0.01**). Limitation: In this study, sample size was small and the age span was not large enough. Conclusions: This study verified the feasibility and adaptability of the proposed evoked paradigm to improve the quality of the gamma-ASSR, which is significant in clinical application. The results suggested that 40 Hz ASSR evoked by chirp stimuli had the best performance and was expected to be used in clinical practice, especially in the field of mental diseases such as schizophrenia, Alzheimer’s disease, and affective disorder.

scholarly journals 40-Hz steady state response in Alzheimer's disease and mild cognitive impairment

2011 ◽  
Vol 32 (1) ◽  
pp. 24-30 ◽  
Author(s):  
J.A. van Deursen ◽  
E.F.P.M. Vuurman ◽  
V.H.J.M. van Kranen-Mastenbroek ◽  
F.R.J. Verhey ◽  
W.J. Riedel
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Steady State ◽  
Mild Cognitive Impairment ◽  
Steady State Response ◽  
State Response ◽  
40 Hz

Case Studies in Dementia-Related Anxiety

GeroPsych ◽  
2020 ◽  
pp. 1-6
Author(s):  
Molly Maxfield ◽  
Jennifer R. Roberts ◽  
JoAnna Dieker
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Social Withdrawal ◽  
Cognitive Status ◽  
Generalized Anxiety ◽  
Neurocognitive Disorder ◽  
High Genetic Risk ◽  
Disease Case ◽  
Negative Perceptions

Abstract. Two clients seeking neuropsychological assessment reported anxiety about their cognitive status. We review the cases to increase our understanding of factors contributing to dementia-related anxiety. Case 1 met the criteria for mild neurocognitive disorder; the client’s memory was impaired, and she had a high genetic risk for Alzheimer’s disease. The client reported anxiety about negative perceptions of quality of life among individuals diagnosed with Alzheimer’s disease. Case 2 did not meet the criteria for a neurocognitive disorder. Anxiety about this client’s cognitive status appeared attributable to generalized anxiety disorder, given his anxiety about diverse topics. Both clients reported embarrassment about forgetfulness and social withdrawal. Dementia-related anxiety is believed to be relatively common, to exist on a continuum, to have unique social implications, and to stem from various sources, necessitating differing interventions.

Validación de la escala Quality of Life in Alzheimer’s Disease (QOL-AD) en pacientes mexicanos con demencia tipo Alzheimer, vascular y mixta

2010 ◽  
Vol 51 (02) ◽  
pp. 72 ◽  
Author(s):  
Oscar Rosas Carrasco ◽  
Laura del Pilar Torres Arreola ◽  
María de Guadalupe Guerra Silla ◽  
Sara Torres Castro ◽  
Luis Miguel Gutiérrez Robledo
Keyword(s):  
Quality Of Life ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease

SPECIFIC PROPERTIES OF TUBULIN IN THE PREFRONTAL CORTEX IN CONTROL, SCHIZOPHRENIA AND VASCULAR DEMENTIA

2020 ◽  
pp. 65-71
Author(s):  
Burbaeva G.Sh. ◽  
Androsova L.V. ◽  
Vorobyeva E.A. ◽  
Savushkina O.K.
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Prefrontal Cortex ◽  
Vascular Dementia ◽  
Binding Activity ◽  
Nephelometric Method ◽  
Rate Of Polymerization ◽  
Mental Diseases ◽  
And Control ◽  
The Brain

The aim of the study was to evaluate the rate of polymerization of tubulin into microtubules and determine the level of colchicine binding (colchicine-binding activity of tubulin) in the prefrontal cortex in schizophrenia, vascular dementia (VD) and control. Colchicine-binding activity of tubulin was determined by Sherlinе in tubulin-enriched extracts of proteins from the samples. Measurement of light scattering during the polymerization of the tubulin was carried out using the nephelometric method at a wavelength of 450-550 nm. There was a significant decrease in colchicine-binding activity and the rate of tubulin polymerization in the prefrontal cortex in both diseases, and in VD to a greater extent than in schizophrenia. The obtained results suggest that not only in Alzheimer's disease, but also in other mental diseases such as schizophrenia and VD, there is a decrease in the level of tubulin in the prefrontal cortex of the brain, although to a lesser extent than in Alzheimer's disease, and consequently the amount of microtubules.

Integrated Biomarkers for Depression in Alzheimer’s Disease: A Critical Review

2017 ◽  
Vol 14 (4) ◽  
pp. 441-452 ◽  
Author(s):  
Sofia Wenzler ◽  
Christian Knochel ◽  
Ceylan Balaban ◽  
Dominik Kraft ◽  
Juliane Kopf ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Affect Regulation ◽  
Current Evidence ◽  
Diagnostic Process ◽  
Neuropsychiatric Manifestation ◽  
The Brain ◽  
Control Functional

Depression is a common neuropsychiatric manifestation among Alzheimer’s disease (AD) patients. It may compromise everyday activities and lead to a faster cognitive decline as well as worse quality of life. The identification of promising biomarkers may therefore help to timely initiate and improve the treatment of preclinical and clinical states of AD, and to improve the long-term functional outcome. In this narrative review, we report studies that investigated biomarkers for AD-related depression. Genetic findings state AD-related depression as a rather complex, multifactorial trait with relevant environmental and inherited contributors. However, one specific set of genes, the brain derived neurotrophic factor (BDNF), specifically the Val66Met polymorphism, may play a crucial role in AD-related depression. Regarding neuroimaging markers, the most promising findings reveal structural impairments in the cortico-subcortical networks that are related to affect regulation and reward / aversion control. Functional imaging studies reveal abnormalities in predominantly frontal and temporal regions. Furthermore, CSF based biomarkers are seen as potentially promising for the diagnostic process showing abnormalities in metabolic pathways that contribute to AD-related depression. However, there is a need for standardization of methodological issues and for replication of current evidence with larger cohorts and prospective studies.

scholarly journals Could Altered Evoked Pain Responsiveness Be a Phenotypic Biomarker for Alzheimer’s Disease Risk? A Cross-Sectional Analysis of Cognitively Healthy Individuals

2020 ◽  
pp. 1-7
Author(s):  
Raymond R. Romano ◽  
Michael A. Carter ◽  
Mary S. Dietrich ◽  
Ronald L. Cowan ◽  
Stephen P. Bruehl ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Healthy Subjects ◽  
Pain Sensitivity ◽  
Late Onset ◽  
Thermal Pain ◽  
Apoe4 Allele ◽  
Increased Risk ◽  
Pain Stimuli ◽  
Experimentally Induced

Background: This study evaluated whether the apolipoprotein ɛ4 (APOE4) allele, a genetic marker associated with increased risk of developing late-onset Alzheimer’s disease (AD), was associated with differences in evoked pain responsiveness in cognitively healthy subjects. Objective: The aim was to determine whether individuals at increased risk of late-onset AD based on APOE allele genotype differ phenotypically in their response to experimentally-induced painful stimuli compared to those who do not have at least one copy of the ɛ4 allele. Methods: Forty-nine cognitively healthy subjects aged 30–89 years old with the APOE4 allele (n = 12) and without (n = 37) were assessed for group differences in pain thresholds and affective (unpleasantness) responses to experimentally-induced thermal pain stimuli. Results: Statistically significant main effects of APOE4 status were observed for both the temperature at which three different pain intensity percepts were reached (p = 0.040) and the level of unpleasantness associated with each (p = 0.014). APOE4 positive participants displayed lower overall pain sensitivity than those who were APOE4 negative and also greater overall levels of pain unpleasantness regardless of intensity level. Conclusion: Cognitively healthy APOE4 carriers at increased risk of late-onset AD demonstrated reduced thermal pain sensitivity but greater unpleasantness to thermal pain stimuli relative to individuals at lower risk of late-onset AD. These results suggest that altered evoked pain perception could potentially be used as a phenotypic biomarker of late-onset AD risk prior to disease onset. Additional studies of this issue may be warranted.

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