Information that initially is presumed to be correct, but that is later retracted or corrected, often continues to influence memory and reasoning. This occurs even if the retraction itself is well ...remembered. The present study investigated whether the continued influence of misinformation can be reduced by explicitly warning people at the outset that they may be misled. A specific warning— giving detailed information about the continued influence effect (CIE)—succeeded in reducing the continued reliance on outdated information but did not eliminate it. A more general warning—reminding people that facts are not always properly checked before information is disseminated—was even less effective. In an additional experiment, a specific warning was combined with the provision of a plausible alternative explanation for the retracted information. This combined manipulation further reduced the CIE but still failed to eliminate it altogether.
Objective
Alzheimer disease (AD) is characterized by functional impairment in the neural elements and circuits underlying cognitive and memory functions. We hypothesized that fornix/hypothalamus deep ...brain stimulation (DBS) could modulate neurophysiological activity in these pathological circuits and possibly produce clinical benefits.
Methods
We conducted a phase I trial in 6 patients with mild AD receiving ongoing medication treatment. Patients received continuous stimulation for 12 months. Three main lines of investigation were pursued including: (1) mapping the brain areas whose physiological function was modulated by stimulation using standardized low‐resolution electromagnetic tomography, (2) assessing whether DBS could correct the regional alterations in cerebral glucose metabolism in AD using positron emission tomography (PET), and 3) measuring the effects of DBS on cognitive function over time using clinical scales and instruments.
Results
DBS drove neural activity in the memory circuit, including the entorhinal, and hippocampal areas and activated the brain's default mode network. PET scans showed an early and striking reversal of the impaired glucose utilization in the temporal and parietal lobes that was maintained after 12 months of continuous stimulation. Evaluation of the Alzheimer's Disease Assessment Scale cognitive subscale and the Mini Mental State Examination suggested possible improvements and/or slowing in the rate of cognitive decline at 6 and 12 months in some patients. There were no serious adverse events.
Interpretation
There is an urgent need for novel therapeutic approaches for AD. Modulating pathological brain activity in this illness with DBS merits further investigation. Ann Neurol 2010
Objectives
To investigate the rate of occurrence of neuropsychiatric symptoms (NPS) and their relationship with age, sex and cognitive performance in subjects with Alzheimer's disease and related ...dementias (Alzheimer's disease and related dementias ADRD).
Methods
This is a retrospective matched case‐control study. Data from memory clinic patients included demographic information presence of NPS, and cognitive testing of Orientation, Immediate and Delayed Memory, Visuospatial Function, Working Memory, Attention, Executive Control and Language. Participants were Individuals with subjective cognitive impairment (n = 352), mild cognitive impairment (MCI) (n = 369), vascular MCI (n = 80), Alzheimer's disease (n = 147), vascular dementia (n = 41), mixed dementia (n = 33), and healthy controls (n = 305). Logistic regression was used to investigate the relationship between the presence of NPS, age and sex. A generalised additive model was used to investigate the relationship between presence of NPS, age and cognitive impairment. Analysis of variance was used to investigate differences in cognition between younger and older groups with and without NPS.
Results
We found an increased likelihood of occurrence of NPS in younger individuals and females across cohorts. Anxiety, depression, agitation, and apathy were associated with higher overall rate of NPS. We also found that individuals under 65 years of age with NPS had worse cognitive scores than their counterpart without NPS.
Conclusion
The younger group with ADRD and NPS had lower cognitive scores, probably reflecting more aggressive neurodegenerative disease. Further work will be needed to elicit the degree to which imaging or mechanistic abnormalities distinguish this group.
Key points
Younger individuals with Alzheimer's disease and related dementias (ADRD) were more likely to present with neuropsychiatric symptoms (NPS) than older individuals.
Younger individuals with ADRD and NPS showed lower cognitive scores than individuals in the same age group without NPS, which was not observed in the older group.
The Ascertain Dementia 8-item Questionnaire (AD8) is a screening tool for cognitive impairment that can be administered to older persons and/or their informants.
To evaluate the diagnostic accuracy ...and compare the predictive parameters of the informant and participant-completed Ascertain Dementia 8-item Questionnaire (iAD8 and pAD8, respectively) in older adults with cognitive impairment.
We searched ten electronic databases (including MEDLINE (Ovid), Embase) from tool inception to March 2022. We included studies with patients ≥60 years old that were screened for cognitive impairment using AD8 in any healthcare setting. Predictive parameters were assessed against reference standards to estimate accuracy and diagnostic ability using bivariate random-effects meta-analyses. We used QUADAS-2 criteria to assess risk of bias.
A cut-off of ≥2/8 was used to classify mild cognitive impairment (MCI), dementia, and cognitive impairment (MCI or dementia). Seven studies using the iAD8 (n = 794) showed a sensitivity of 80% and specificity of 79% to detect MCI. Nine studies using the iAD8 (n = 2393) established 91% sensitivity and 64% specificity to detect dementia. To detect MCI using the pAD8, four studies (n = 836) showed 57% sensitivity and 71% specificity. To detect dementia using the pAD8, four studies (n = 3015) demonstrated 82% sensitivity and 75% specificity. Recurring high or unclear risk of bias was noted in the domains of "Index test" and "reference standard".
The diagnostic accuracy of iAD8 is superior to that of pAD8 when screening for cognitive impairment. The AD8 may be an acceptable alternative to screen for cognitive impairment in older adults when there are limitations to formal testing.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study examines reading aloud in patients with amyotrophic lateral sclerosis (ALS) and those with frontotemporal dementia (FTD) in order to determine whether differences in patterns of speaking ...and pausing exist between patients with primary motor vs. primary cognitive-linguistic deficits, and in contrast to healthy controls.
136 participants were included in the study: 33 controls, 85 patients with ALS, and 18 patients with either the behavioural variant of FTD (FTD-BV) or progressive nonfluent aphasia (FTD-PNFA). Participants with ALS were further divided into 4 non-overlapping subgroups--mild, respiratory, bulbar (with oral-motor deficit) and bulbar-respiratory--based on the presence and severity of motor bulbar or respiratory signs. All participants read a passage aloud. Custom-made software was used to perform speech and pause analyses, and this provided measures of speaking and articulatory rates, duration of speech, and number and duration of pauses. These measures were statistically compared in different subgroups of patients.
The results revealed clear differences between patient groups and healthy controls on the passage reading task. A speech-based motor function measure (i.e., articulatory rate) was able to distinguish patients with bulbar ALS or FTD-PNFA from those with respiratory ALS or FTD-BV. Distinguishing the disordered groups proved challenging based on the pausing measures.
This study demonstrated the use of speech measures in the identification of those with an oral-motor deficit, and showed the usefulness of performing a relatively simple reading test to assess speech versus pause behaviors across the ALS-FTD disease continuum. The findings also suggest that motor speech assessment should be performed as part of the diagnostic workup for patients with FTD.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The unprecedented rise in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections during December 2021 was concurrent with rapid spread of the Omicron variant in England and globally. ...We analyzed the prevalence of SARS-CoV-2 and its dynamics in England from the end of November to mid-December 2021 among almost 100,000 participants in the REACT-1 study. Prevalence was high with rapid growth nationally and particularly in London during December 2021, with an increasing proportion of infections due to Omicron. We observed large decreases in swab positivity among mostly vaccinated older children (12 to 17 years) relative to unvaccinated younger children (5 to 11 years), and in adults who received a third (booster) vaccine dose versus two doses. Our results reinforce the importance of vaccination and booster campaigns, although additional measures have been needed to control the rapid growth of the Omicron variant.
Article Note: Relevant conflicts of interest/financial disclosures: A.F. received research support and honoraria from Medtronic. C.W. received honoraria from Codman, Integra. A.J.E., D.F.T.-W. and ...J.K.K. have no disclosures. Funding agencies: None. Byline: Alfonso Fasano, Alberto J. Espay, David F. Tang-Wai, Carsten Wikkelso, Joachim K. Krauss
Degraded social function, disinhibition, and stereotypy are defining characteristics of frontotemporal dementia (FTD), manifesting in both the behavioral variant of frontotemporal dementia (bvFTD) ...and semantic dementia (SD) subtypes. Recent neuroimaging research also associates FTD with alterations in the brain's intrinsic connectivity networks. The present study explored the relationship between neural network connectivity and specific behavioral symptoms in FTD.
Resting-state functional magnetic resonance imaging was employed to investigate neural network changes in bvFTD and SD. We used independent components analysis (ICA) to examine changes in frontolimbic network connectivity, as well as several metrics of local network strength, such as the fractional amplitude of low-frequency fluctuations, regional homogeneity, and seed-based functional connectivity. For each analysis, we compared each FTD subgroup to healthy controls, characterizing general and subtype-unique network changes. The relationship between abnormal connectivity in FTD and behavior disturbances was explored.
Across multiple analytic approaches, both bvFTD and SD were associated with disrupted frontolimbic connectivity and elevated local connectivity within the prefrontal cortex. Even after controlling for structural atrophy, prefrontal hyperconnectivity was robustly associated with apathy scores. Frontolimbic disconnection was associated with lower disinhibition scores, suggesting that abnormal frontolimbic connectivity contributes to positive symptoms in dementia. Unique to bvFTD, stereotypy was associated with elevated default network connectivity in the right angular gyrus. The behavioral variant was also associated with marginally higher apathy scores and a more diffuse pattern of prefrontal hyperconnectivity than SD.
The present findings support a theory of FTD as a disorder of frontolimbic disconnection leading to unconstrained prefrontal connectivity. Prefrontal hyperconnectivity may represent a compensatory response to the absence of affective feedback during the planning and execution of behavior. Increased reliance upon prefrontal processes in isolation from subcortical structures appears to be maladaptive and may drive behavioral withdrawal that is commonly observed in later phases of neurodegeneration.
Internal gravity waves, the subsurface analogue of the familiar surface gravity waves that break on beaches, are ubiquitous in the ocean. Because of their strong vertical and horizontal currents, and ...the turbulent mixing caused by their breaking, they affect a panoply of ocean processes, such as the supply of nutrients for photosynthesis, sediment and pollutant transport and acoustic transmission; they also pose hazards for man-made structures in the ocean. Generated primarily by the wind and the tides, internal waves can travel thousands of kilometres from their sources before breaking, making it challenging to observe them and to include them in numerical climate models, which are sensitive to their effects. For over a decade, studies have targeted the South China Sea, where the oceans' most powerful known internal waves are generated in the Luzon Strait and steepen dramatically as they propagate west. Confusion has persisted regarding their mechanism of generation, variability and energy budget, however, owing to the lack of in situ data from the Luzon Strait, where extreme flow conditions make measurements difficult. Here we use new observations and numerical models to (1) show that the waves begin as sinusoidal disturbances rather than arising from sharp hydraulic phenomena, (2) reveal the existence of >200-metre-high breaking internal waves in the region of generation that give rise to turbulence levels >10,000 times that in the open ocean, (3) determine that the Kuroshio western boundary current noticeably refracts the internal wave field emanating from the Luzon Strait, and (4) demonstrate a factor-of-two agreement between modelled and observed energy fluxes, which allows us to produce an observationally supported energy budget of the region. Together, these findings give a cradle-to-grave picture of internal waves on a basin scale, which will support further improvements of their representation in numerical climate predictions.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
