scholarly journals Witnessed apneas are associated with elevated tau-PET levels in cognitively unimpaired elderly

Neurology ◽  
2020 ◽  
Vol 94 (17) ◽  
pp. e1793-e1802 ◽  
Author(s):  
Diego Z. Carvalho ◽  
Erik K. St. Louis ◽  
Christopher G. Schwarz ◽  
Val J. Lowe ◽  
Bradley F. Boeve ◽  
...  
Keyword(s):  
Linear Models ◽  
Temporal Cortex ◽  
Standardized Uptake Value ◽  
Brain Regions ◽  
Population Based ◽  
Inferior Temporal Cortex ◽  
Elderly Persons ◽  
Cross Sectional ◽  
Tau Pet ◽  
Close Relatives

ObjectiveTo assess whether informant-reported apneas during sleep (witnessed apneas) in cognitively unimpaired (CU) elderly persons are associated with higher levels of brain tau.MethodsFrom the population-based Mayo Clinic Study of Aging, we identified 292 CU elderly ≥65 years of age with both AV-1451 tau-PET and Pittsburgh compound B (PiB)-PET scans and whose bed partners and close relatives had completed a questionnaire that assessed whether participants had witnessed apneas during sleep. For this cross-sectional analysis, we selected the entorhinal and inferior temporal cortices as our regions of interest (ROIs) because they are highly susceptible to tau accumulation. PET signal was scaled to the cerebellum crus to calculate standardized uptake value ratio (SUVR). We fit linear models to assess the association between regional tau and witnessed apneas while controlling for age, sex, years of education, body mass index, hypertension, hyperlipidemia, diabetes, reduced sleep, excessive daytime sleepiness, and global PiB.ResultsForty-three participants (14.7%) were found to have witnessed apneas during sleep. The report of witnessed apneas was associated with higher tau-PET SUVR elevation in our ROIs: 0.049 SUVR (95% confidence interval [CI] 0.010–0.087, p = 0.015) in the entorhinal cortex and 0.037 SUVR (95% CI 0.006–0.067, p = 0.019) in the inferior temporal cortex after controlling for confounders.ConclusionWe identified a significant association between witnessed apneas in CU elderly and elevated tau-PET signal in tau-susceptible brain regions. These results suggest a plausible mechanism that could contribute to cognitive impairment and the development of Alzheimer disease. Longitudinal observations are necessary to determine direction of causality.

scholarly journals Cross-sectional associations of tau-PET signal with cognition in cognitively unimpaired adults

Neurology ◽  
2019 ◽  
Vol 93 (1) ◽  
pp. e29-e39 ◽  
Author(s):  
Val J. Lowe ◽  
Tyler J. Bruinsma ◽  
Heather J. Wiste ◽  
Hoon-Ki Min ◽  
Stephen D. Weigand ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Medial Temporal Lobe ◽  
Memory Performance ◽  
Standardized Uptake Value ◽  
Brain Regions ◽  
Population Based ◽  
Cognitive Test ◽  
Amyloid Pet ◽  
Cross Sectional ◽  
Tau Pet

ObjectiveTo assess cross-sectional associations of neurofibrillary tangles, measured by tau-PET, with cognitive performance in cognitively unimpaired (CU) adults.MethodsTau- and amyloid-PET were performed in 579 CU participants aged 50–98 from the population-based Mayo Clinic Study of Aging. Associations between tau-PET signal in 43 brain regions and cognitive test scores were assessed using penalized linear regression. In additional models, participants were classified by normal/abnormal global amyloid-PET (A+/A−) and normal/abnormal regional tau-PET (T+/T−). Regional tau-PET cutpoints were defined as standardized uptake value ratio (SUVR) greater than the 95th percentile of tau-PET SUVR in that region among 117 CU participants aged 30–49.ResultsHigher tau-PET signal was associated with poorer memory performance in all medial temporal lobe (MTL) regions and also in the middle temporal pole and frontal olfactory regions. The largest association with tau-PET and memory z scores was seen in the entorhinal cortex; this association was independent of tau-PET signal in other brain regions. Tau-PET in the entorhinal cortex was also associated with poorer global and language performance. In the entorhinal cortex, T+ was associated with lower memory performance among both A− and A+.ConclusionsTau deposition in MTL regions, as reflected by tau-PET signal, was associated with poorer performance on memory tests in CU participants. The association with entorhinal cortex tau-PET was independent of tau-PET signal in other brain regions. Longitudinal studies are needed to understand the fate of CU participants with elevated medial temporal tau-PET signal.

scholarly journals Brain Mechanisms of Arithmetic: A Crucial Role for Ventral Temporal Cortex

2018 ◽  
Vol 30 (12) ◽  
pp. 1757-1772 ◽  
Author(s):  
Pedro Pinheiro-Chagas ◽  
Amy Daitch ◽  
Josef Parvizi ◽  
Stanislas Dehaene
Keyword(s):  
Numerical Cognition ◽  
Parietal Lobe ◽  
Temporal Cortex ◽  
Classical Problem ◽  
Brain Regions ◽  
Inferior Temporal Cortex ◽  
Problem Size ◽  
Ventral Temporal Cortex ◽  
Intracranial Electroencephalography ◽  
Problem Size Effect

Elementary arithmetic requires a complex interplay between several brain regions. The classical view, arising from fMRI, is that the intraparietal sulcus (IPS) and the superior parietal lobe (SPL) are the main hubs for arithmetic calculations. However, recent studies using intracranial electroencephalography have discovered a specific site, within the posterior inferior temporal cortex (pITG), that activates during visual perception of numerals, with widespread adjacent responses when numerals are used in calculation. Here, we reexamined the contribution of the IPS, SPL, and pITG to arithmetic by recording intracranial electroencephalography signals while participants solved addition problems. Behavioral results showed a classical problem size effect: RTs increased with the size of the operands. We then examined how high-frequency broadband (HFB) activity is modulated by problem size. As expected from previous fMRI findings, we showed that the total HFB activity in IPS and SPL sites increased with problem size. More surprisingly, pITG sites showed an initial burst of HFB activity that decreased as the operands got larger, yet with a constant integral over the whole trial, thus making these signals invisible to slow fMRI. Although parietal sites appear to have a more sustained function in arithmetic computations, the pITG may have a role of early identification of the problem difficulty, beyond merely digit recognition. Our results ask for a reevaluation of the current models of numerical cognition and reveal that the ventral temporal cortex contains regions specifically engaged in mathematical processing.

scholarly journals Color signals through dorsal and ventral visual pathways

2013 ◽  
Vol 31 (2) ◽  
pp. 197-209 ◽  
Author(s):  
BEVIL R. CONWAY
Keyword(s):  
Visual Processing ◽  
Color Space ◽  
Temporal Cortex ◽  
Color Perception ◽  
Original Data ◽  
Brain Regions ◽  
Neural Representation ◽  
Inferior Temporal Cortex ◽  
Extrastriate Cortex ◽  
Chromatic Contrast

AbstractExplanations for color phenomena are often sought in the retina, lateral geniculate nucleus, and V1, yet it is becoming increasingly clear that a complete account will take us further along the visual-processing pathway. Working out which areas are involved is not trivial. Responses to S-cone activation are often assumed to indicate that an area or neuron is involved in color perception. However, work tracing S-cone signals into extrastriate cortex has challenged this assumption: S-cone responses have been found in brain regions, such as the middle temporal (MT) motion area, not thought to play a major role in color perception. Here, we review the processing of S-cone signals across cortex and present original data on S-cone responses measured with fMRI in alert macaque, focusing on one area in which S-cone signals seem likely to contribute to color (V4/posterior inferior temporal cortex) and on one area in which S signals are unlikely to play a role in color (MT). We advance a hypothesis that the S-cone signals in color-computing areas are required to achieve a balanced neural representation of perceptual color space, whereas those in noncolor-areas provide a cue to illumination (not luminance) and confer sensitivity to the chromatic contrast generated by natural daylight (shadows, illuminated by ambient sky, surrounded by direct sunlight). This sensitivity would facilitate the extraction of shape-from-shadow signals to benefit global scene analysis and motion perception.

scholarly journals Comparison of Primate Prefrontal and Premotor Cortex Neuronal Activity during Visual Categorization

2011 ◽  
Vol 23 (11) ◽  
pp. 3355-3365 ◽  
Author(s):  
Jason A. Cromer ◽  
Jefferson E. Roy ◽  
Timothy J. Buschman ◽  
Earl K. Miller
Keyword(s):  
Premotor Cortex ◽  
Temporal Cortex ◽  
Motor Planning ◽  
Brain Regions ◽  
Inferior Temporal Cortex ◽  
Decision Variable ◽  
Final Decision ◽  
Visual Categorization ◽  
Category Information ◽  
Cognitive Problem

Previous work has shown that neurons in the PFC show selectivity for learned categorical groupings. In contrast, brain regions lower in the visual hierarchy, such as inferior temporal cortex, do not seem to favor category information over information about physical appearance. However, the role of premotor cortex (PMC) in categorization has not been studied, despite evidence that PMC is strongly engaged by well-learned tasks and reflects learned rules. Here, we directly compare PFC neurons with PMC neurons during visual categorization. Unlike PFC neurons, relatively few PMC neurons distinguished between categories of visual images during a delayed match-to-category task. However, despite the lack of category information in the PMC, more than half of the neurons in both PFC and PMC reflected whether the category of a test image did or did not match the category of a sample image (i.e., had match information). Thus, PFC neurons represented all variables required to solve the cognitive problem, whereas PMC neurons instead represented only the final decision variable that drove the appropriate motor action required to obtain a reward. This dichotomy fits well with PFC's hypothesized role in learning arbitrary information and directing behavior as well as the PMC's role in motor planning.

scholarly journals Modulation in Alpha Band Activity Reflects Syntax Composition: An MEG Study of Minimal Syntactic Binding

2021 ◽  
Author(s):  
Sophie M Hardy ◽  
Ole Jensen ◽  
Linda Wheeldon ◽  
Ali Mazaheri ◽  
Katrien Segaert
Keyword(s):  
Target Word ◽  
Sentence Comprehension ◽  
Inferior Frontal Gyrus ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Inferior Temporal Cortex ◽  
Alpha Power ◽  
Sentence Structure ◽  
Alpha Band ◽  
Syntactic Binding

Successful sentence comprehension requires the binding, or composition, of multiple words into larger structures to establish meaning. Using magnetoencephalography (MEG), we investigated the neural mechanisms involved in binding of language at the level of syntax, in a task in which contributions from semantics were minimized. Participants were auditorily presented with minimal sentences that required binding (pronoun and pseudo-verb with the corresponding morphological inflection; "she grushes") and wordlists that did not require binding (two pseudo-verbs; "cugged grushes"). Relative to the no binding wordlist condition, we found that syntactic binding in a minimal sentence structure was associated with a modulation in alpha band (8-12 Hz) activity in left-lateralized brain regions. First, in the sentence condition, we observed a significantly smaller increase in alpha power around the presentation of the target word ("grushes") that required binding (-0.05s to 0.1s), which we suggest reflects an expectation of binding to occur. Second, following the presentation of the target word (around 0.15s to 0.25s), during syntactic binding we observed significantly decreased alpha phase-locking between the left inferior frontal gyrus and the left middle/inferior temporal cortex. We suggest that this results from alpha-driven cortical disinhibition serving to increase information transfer between these two brain regions and strengthen the syntax composition neural network. Together, our findings highlight that successful syntax composition is underscored by the rapid spatial-temporal activation and coordination of language-relevant brain regions, and that alpha band oscillations are critically important in controlling the allocation and transfer of the brain's resources during syntax composition.

scholarly journals Characteristics of falls in elderly persons residing in the community: a population-based study

2017 ◽  
Vol 20 (5) ◽  
pp. 691-701 ◽  
Author(s):  
Suzana Albuquerque de Moraes ◽  
Wuber Jefferson Sousa Soares ◽  
Lygia Paccini Lustosa ◽  
Tereza Loffredo Bilton ◽  
Eduardo Ferrioli ◽  
...  
Keyword(s):  
The Elderly ◽  
Sociodemographic Factors ◽  
Population Based ◽  
The State ◽  
Elderly Persons ◽  
Chi Square ◽  
Cross Sectional ◽  
Population Based Study ◽  
Mato Grosso ◽  
Chi Square Test

Abstract Object: to examine the characteristics to the last fall of Brazilian elderly persons who experienced falls in 2008 and 2009, and to identify if there is a relationship with sociodemographic characteristics, physical health, comorbidities, clinical conditions and the circumstances of the falls. Methods: a cross-sectional, population based study was carried out with participants aged 65 and older from Barueri in the state of São Paulo and Cuiabá in the state of Mato Grosso, Brazil. Households were enrolled within each census region according to population density and the number of elderly persons living in each region. A multidimensional questionnaire composed of sociodemographic factors and data regarding falls was used. Associations were analyzed using contingency tables, and Fisher's Exact or Pearson's Chi-square test was used. Results: 774 elderly people were included in the study, 299 of whom reported falling in the previous year. Of these, 176 (58.9%) had fallen once and 123 (41.1%) reported having fallen twice or more. Among fallers the mean age was 72.53 (±6.12) years and 214 (71.6%) were female. About 107 (35.8%) of the elderly reported having fallen forwards, 79 (26.4%) fell to the side and 42(14%) fell backwards. Regarding the circumstances of the falls, 107 (35.8%) reported having lost their balance, 79 (26.4%) said they had stumbled and 42 (14%) said they had slipped. There was an association between the mechanism and circumstances of the falls and having fallen once or twice or more. There was an association between the circumstances of falls and the number of medications taken. Conclusion: The characteristics of falls were different among elderly persons who had fallen once or twice or more, which may guide health professionals, the elderly and their families in relation to specific fall prevention strategies.

Elevated Tau PET Signal Depends on Abnormal Amyloid Levels and Correlates with Cognitive Impairment in Elderly Persons without Dementia

2020 ◽  
Vol 78 (1) ◽  
pp. 395-404 ◽  
Author(s):  
Rui-Qi Zhang ◽  
Shi-Dong Chen ◽  
Xue-Ning Shen ◽  
Yu-Xiang Yang ◽  
Jia-Ying Lu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Executive Function ◽  
Amyloid Β ◽  
Amyloid Pet ◽  
Elderly Persons ◽  
Cross Sectional ◽  
Memory Decline ◽  
Tau Pet

Background: The recent developed PET ligands for amyloid-β (Aβ) and tau allow these two neuropathological hallmarks of Alzheimer’s disease (AD) to be mapped and quantified in vivo and to be examined in relation to cognition. Objective: To assess the associations among Aβ, tau, and cognition in non-demented subjects. Methods: Three hundred eighty-nine elderly participants without dementia from the Alzheimer’s Disease Neuroimaging Initiative underwent tau and amyloid PET scans. Cross-sectional comparisons and longitudinal analyses were used to evaluate the relationship between Aβ and tau accumulation. The correlations between biomarkers of both pathologies and performance in memory and executive function were measured. Results: Increased amyloid-PET retention was associated with greater tau-PET retention in widespread cortices. We observed a significant tau increase in the temporal composite regions of interest over 24 months in Aβ+ but not Aβ– subjects. Finally, tau-PET retention but not amyloid-PET retention significantly explained the variance in memory and executive function. Higher level of tau was associated with greater longitudinal memory decline. Conclusion: These findings suggested PET-detectable Aβ plaque pathology may be a necessary antecedent for tau-PET signal elevation. Greater tau-PET retention may demonstrate poorer cognition and predict prospective memory decline in non-demented subjects.

scholarly journals Factors associated with adherence to pharmacological treatment among elderly persons using antihypertensive drugs

2017 ◽  
Vol 20 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Glenda de Almeida Aquino ◽  
Danielle Teles da Cruz ◽  
Marcelo Silva Silvério ◽  
Marcel de Toledo Vieira ◽  
Ronaldo Rocha Bastos ◽  
...  
Keyword(s):  
Elderly Patients ◽  
Antihypertensive Drugs ◽  
Wald Test ◽  
Population Based ◽  
Pharmacological Therapy ◽  
Elderly Persons ◽  
Positive Perception ◽  
Cross Sectional ◽  
Adherence To Medication ◽  
Level Of Significance

Abstract Objective: analyze adherence to pharmacotherapy and associated factors among elderly patients using at least one antihypertensive medication. Methods: A cross-sectional, population-based study was performed of elderly patients resident in Juiz de Fora, Minas Gerais, Brazil. Adherence to medication was assessed with the Morisky-Green Test. Socio-demographic variables and variables related to health status, the health service and drug therapy were collected. The Poisson regression model was used to assess crude and adjusted (95% confidence interval) prevalence ratios (PR). The level of significance was tested using the Wald test. Results: The prevalence of adherence to pharmacological therapy was 47% (95% CI: 41%-53%). The sample consisted of 279 elderly persons, the majority of whom were women (69%), described themselves as white (45.5%), and had up to four years of schooling (76.48%). Regarding pharmacological therapy, the subjects took 5.19 (±2.8) medications and 7.1 (±4.4) tablets per day. Conclusion: a significant association was observed between adherence to pharmacological therapy and the variables positive perception of vision, positive perception of hearing and absence of frailty.

scholarly journals KL-VS heterozygosity is associated with lower amyloid-dependent tau accumulation and memory impairment in Alzheimer’s disease

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Julia Neitzel ◽  
Nicolai Franzmeier ◽  
Anna Rubinski ◽  
Martin Dichgans ◽  
Matthias Brendel ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Regions ◽  
Protective Role ◽  
Amyloid Pet ◽  
Tau Pathology ◽  
Cross Sectional ◽  
Memory Impairments ◽  
Amyloid A ◽  
Tau Pet

AbstractKlotho-VS heterozygosity (KL-VShet) is associated with reduced risk of Alzheimer’s disease (AD). However, whether KL-VShet is associated with lower levels of pathologic tau, i.e., the key AD pathology driving neurodegeneration and cognitive decline, is unknown. Here, we assessed the interaction between KL-VShet and levels of beta-amyloid, a key driver of tau pathology, on the levels of PET-assessed neurofibrillary tau in 551 controls and patients across the AD continuum. KL-VShet showed lower cross-sectional and longitudinal increase in tau-PET per unit increase in amyloid-PET when compared to that of non-carriers. This association of KL-VShet on tau-PET was stronger in Klotho mRNA-expressing brain regions mapped onto a gene expression atlas. KL-VShet was related to better memory functions in amyloid-positive participants and this association was mediated by lower tau-PET. Amyloid-PET levels did not differ between KL-VShet carriers versus non-carriers. Together, our findings provide evidence to suggest a protective role of KL-VShet against amyloid-related tau pathology and tau-related memory impairments in elderly humans at risk of AD dementia.

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