共查询到20条相似文献，搜索用时 31 毫秒
1.
Paola Gilsanz Maria M. Corrada Claudia H. Kawas Elizabeth Rose Mayeda M. Maria Glymour Charles P. Quesenberry Catherine Lee Rachel A. Whitmer 《Alzheimer's & dementia》2019,15(4):497-505
Introduction
Little is known about dementia incidence in diverse populations of oldest-old, the age group with highest dementia incidence.Methods
Incident dementia diagnoses from 1/1/2010 to 9/30/2015 were abstracted from medical records for 2350 members of an integrated health care system in California (n = 1702 whites, n = 375 blacks, n = 105 Latinos, n = 168 Asians) aged ≥90 in 2010. We estimated race/ethnicity-specific age-adjusted dementia incidence rates and implemented Cox proportional hazards models and Fine and Gray competing risk of death models adjusted for demographics and comorbidities in midlife and late-life.Results
Dementia incidence rates (n = 771 cases) were lowest among Asians (89.9/1000 person-years), followed by whites (96.9/1000 person-years), Latinos (105.8/1000 person-years), and blacks (121.5/1000 person-years). Cox regression and competing risk models estimated 28% and 36% higher dementia risk for blacks versus whites adjusting for demographics and comorbidities.Discussion
Patterns of racial/ethnic disparities in dementia seen in younger older adults continue after the age of 90 years, though smaller in magnitude. 相似文献2.
Daniel R. Edgcumbe Volker Thoma Davide Rivolta Michael A. Nitsche Cynthia H.Y. Fu 《Brain stimulation》2019,12(3):652-658
Background
Accounts of cognitive processes in judgment and decision-making are frequently based on a dual-process framework, which reflects two qualitatively different types of processing: intuitive (Type 1) and analytical (Type 2) processes.Objective
The present study investigated the effects of bilateral transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex (DLPFC) on judgment and decision-making performance.Methods
Participants received anodal tDCS stimulation to the right DLPFC, left DLPFC or sham. There were 3 tasks: vignettes measuring heuristic thinking, belief bias syllogisms, and the cognitive reflection test (CRT), a measure of the ability to inhibit automatic responses to reach a correct solution. Fifty-four participants (mean age?=?24.63?±?4.46 years; 29 females) were recruited.Results
Results showed that anodal tDCS to the right DLPFC was associated with an increase in cognitive reflection performance (Type 2 processing) as compared to left DLPFC and to sham. Logic thinking was reduced following anodal tDCS to the left DLPFC.Conclusion
These findings are broadly consistent with a dual process framework, and cannot be explained by differences in cognitive ability and thinking style. The results demonstrate the involvement of the right DLPFC in cognitive reflection, and suggest the possibility of improving cognitive performance through tDCS. 相似文献3.
Diane E. Hosking Ranmalee Eramudugolla Nicolas Cherbuin Kaarin J. Anstey 《Alzheimer's & dementia》2019,15(4):581-589
Introduction
Associations between the Mediterranean-DASH diet Intervention for Neurological Delay (MIND) diet and incidence of cognitive impairment have not been evaluated outside the United States.Methods
We investigated MIND and Mediterranean diet relations with 12-year incidence of Alzheimer's disease/Vascular dementia (National Institute of Neurological Disorders criteria) and mild cognitive impairment (Winbald criteria) in the Personality and Total Health (PATH) Through Life cohort (n = 1220) set in Canberra, Australia: wave-1 2001-2002; wave-2 2005-2006; wave-3 2009-2010; and wave-4 2013-2014.MIND diet and two alternate Mediterranean diet scores were calculated from the baseline food frequency questionnaire responses. Higher dietary scores signified greater adherence.Results
In adjusted logistic regression models, MIND diet (OR = 0.47, 95% CI 0.24, 0.91), but not Mediterranean diet, was associated with reduced odds of 12-year cognitive impairment.Discussion
Preliminary evidence suggests that protective effects of the MIND diet are geographically generalizable. Additional prospective studies are needed in diverse samples to determine the relative effects of the MIND and the Mediterranean diets against cognitive decline. 相似文献4.
Daniel G. da S. Machado Gozde Unal Suellen M. Andrade Alexandre Moreira Leandro R. Altimari André R. Brunoni Stéphane Perrey Alexis R. Mauger Marom Bikson Alexandre H. Okano 《Brain stimulation》2019,12(3):593-605
Background
Transcranial direct current stimulation (tDCS) has been used to improve exercise performance, though the protocols used, and results found are mixed.Objective
We aimed to analyze the effect of tDCS on improving exercise performance.Methods
A systematic search was performed on the following databases, until December 2017: PubMed/MEDLINE, Embase, Web of Science, SCOPUS, and SportDiscus. Full-text articles that used tDCS for exercise performance improvement in adults were included. We compared the effect of anodal (anode near nominal target) and cathodal (cathode near nominal target) tDCS to a sham/control condition on the outcome measure (performance in isometric, isokinetic or dynamic strength exercise and whole-body exercise).Results
22 studies (393 participants) were included in the qualitative synthesis and 11 studies (236 participants) in the meta-analysis. The primary motor cortex (M1) was the main nominal tDCS target (n?=?16; 72.5%). A significant effect favoring anodal tDCS (a-tDCS) applied before exercise over M1 was found on cycling time to exhaustion (mean difference?=?93.41?s; 95%CI?=?27.39?s–159.43?s) but this result was strongly influenced by one study (weight?=?84%), no effect was found for cathodal tDCS (c-tDCS). No significant effect was found for a-tDCS applied on M1 before or during exercise on isometric muscle strength of the upper or lower limbs. Studies regarding a-tDCS over M1 on isokinetic muscle strength presented mixed results. Individual results of studies using a-tDCS applied over the prefrontal and motor cortices either before or during dynamic muscle strength testing showed positive results, but performing meta-analysis was not possible.Conclusion
For the protocols tested, a-tDCS but not c-tDCS vs. sham over M1 improved exercise performance in cycling only. However, this result was driven by a single study, which when removed was no longer significant. Further well-controlled studies with larger sample sizes and broader exploration of the tDCS montages and doses are warranted. 相似文献5.
Lukas Frase Peter Selhausen Lukas Krone Sulamith Tsodor Friederike Jahn Bernd Feige Jonathan G. Maier Florian Mainberger Hannah Piosczyk Marion Kuhn Stefan Klöppel Annette Sterr Chiara Baglioni Kai Spiegelhalder Dieter Riemann Michael A. Nitsche Christoph Nissen 《Brain stimulation》2019,12(3):674-683
Background
Arousal and sleep represent basic domains of behavior, and alterations are of high clinical importance.Objective/hypothesis
The aim of this study was to further elucidate the neurobiology of insomnia disorder (ID) and the potential for new treatment developments, based on the modulation of cortical activity through the non-invasive brain stimulation technique transcranial direct current stimulation (tDCS). Specifically, we tested the hypotheses that bi-frontal anodal tDCS shortens and cathodal tDCS prolongs total sleep time in patients with ID, compared to sham stimulation. Furthermore, we tested for differences in indices of arousal between ID patients and healthy controls and explored their potential impact on tDCS effects.Methods
Nineteen ID patients underwent a within-subject repeated-measures sleep laboratory study with adaptation, baseline and three experimental nights. Bifrontal anodal, cathodal and sham tDCS was delivered in a counterbalanced order immediately prior to sleep. Wake EEG was recorded prior to and after tDCS as well as on the following morning. Subsequently, we compared patients with ID to a healthy control group from an earlier dataset.Results
Against our hypothesis, we did not observe any tDCS effects on sleep continuity or sleep architecture in patients with ID. Further analyses of nights without stimulation demonstrated significantly increased levels of arousal in ID patients compared to healthy controls, as indexed by subjective reports, reduced total sleep time, increased wake after sleep onset and increased high frequency EEG power during wakefulness and NREM sleep. Of note, indices of increased arousal predicted the lack of effect of tDCS in ID patients.Conclusions
Our study characterizes for the first time differential effects of tDCS on sleep in patients with ID and healthy controls, presumably related to persistent hyperarousal in ID. These findings suggest that adapted tDCS protocols need to be developed to modulate arousal and sleep dependent on baseline arousal levels. 相似文献6.
Federico Ranieri Gianluca Coppola Gabriella Musumeci Fioravante Capone Giovanni Di Pino Vincenzo Parisi Vincenzo Di Lazzaro 《Brain stimulation》2019,12(3):705-713
Background
Repetitive convergent inputs to a single post-synaptic neuron can induce long-term potentiation (LTP) or depression (LTD) of synaptic activity in a spike timing-dependent manner.Objective
Here we set a protocol of visual paired associative stimulation (vPAS) of the primary visual cortex (V1) in humans to induce persistent changes in the excitatory properties of V1 with a spike timing rule.Methods
We provided convergent inputs to V1 by coupling transcranial magnetic stimulation (TMS) pulses of the occipital cortex with peripheral visual inputs, at four interstimulus intervals of ?50/-25/+25/+50 ms relative to the visual evoked potential (VEP) P1 latency. We analysed VEP amplitude and delayed habituation before and up to 10 min after each vPAS protocol.Results
VEP amplitude was reduced after vPAS+25. Delayed VEP habituation was increased after vPAS-25 while it was reduced after vPAS+25.Conclusions
We provide evidence that associative bidirectional synaptic plasticity is a feature not only of the sensorimotor but also of the human visual system. 相似文献7.
Chenxi Dai Gang Chen Bihua Chen Juan Wang Changlin Yin Jianjie Wang Yushun Gong Liang Wei Yuanyuan Huang Yongqin Li 《Brain stimulation》2019,12(3):659-667
Background
Transcranial direct current stimulation (tDCS) modulates neuronal activity and is a potential therapeutic tool for many neurological diseases. However, its beneficial effects on post cardiac arrest syndrome remains uncertain.Objective/hypothesis
We investigated the effects of repetitive anodal tDCS on neurological outcome and survival in a ventricular fibrillation (VF) cardiac arrest rat model.Methods
Cardiopulmonary resuscitation was initiated after 6?min of VF in 36 Sprague-Dawley rats. The animals were randomized into three groups immediately after resuscitation (n?=?12 each): no-treatment control (NTC) group, targeted temperature management (TTM) group, and tDCS group. For tDCS, 1?mA anodal tDCS was applied on the dorsal scalp for 0.5?h. The stimulation was repeated for four sessions with 1-h resting interval under normothermia. Post-resuscitation hemodynamic, cerebral, and myocardial injuries, 96-h neurological outcome, and survival were evaluated.Results
Compared with the NTC group, post-resuscitation serum astroglial protein S100 beta and cardiac troponin T levels and 96-h neuronal and myocardial damage scores were markedly reduced in the tDCS and TTM groups. Myocardial ejection fraction, neurological deficit score, and 96-h survival rate were also significantly better for the tDCS and TTM groups. The period of post-resuscitation arrhythmia with hemodynamic instability was considerably shorter in the tDCS group, but no differences were observed in neurological outcome and survival between the tDCS and TTM groups.Conclusions
In this cardiac arrest rat model, repeated anodal tDCS commenced after resuscitation improves 96-h neurological outcome and survival to an extent comparable to TTM by attenuating post-resuscitation cerebral and cardiac injuries. 相似文献8.
Guoqiao Wang Dean Coble Eric M. McDade Jason Hassenstab Anne M. Fagan Tammie L.S. Benzinger Randall J. Bateman John C. Morris Chengjie Xiong 《Alzheimer's & dementia》2019,15(4):506-514
Introduction
Staging preclinical Alzheimer disease (AD) by the expected years to symptom onset (EYO) in autosomal dominant AD (ADAD) through biomarker correlations is important.Methods
We estimated the correlation matrix between EYO/cognition and imaging/CSF biomarkers, and searched for the EYO cutoff where a change in the correlations occurred before and after the cutoff among the asymptomatic mutation carriers of ADAD. We then estimated the longitudinal rate of change for biomarkers/cognition within each preclinical stage defined by the EYO.Results
Based on the change in the correlations, the preclinical ADAD was divided by EYOs ?7 and ?13 years. Mutation carriers demonstrated a temporal ordering of biomarker/cognition changes across the three preclinical stages.Discussion
Duration of each preclinical stage can be estimated in ADAD, facilitating better planning of prevention trials with the EYO cutoffs under the recently released FDA guidance. The generalization of these results to sporadic AD warrants further investigation. 相似文献9.
Sharon G. Curhan Walter C. Willett Francine Grodstein Gary C. Curhan 《Alzheimer's & dementia》2019,15(4):525-533
Introduction
We examined the relation between self-reported hearing loss, hearing aid use, and risk of subjective cognitive function (SCF) decline.Methods
We conducted an 8-year (2008–2016) longitudinal study of 10,107 men aged ≥62 years who reported their hearing status in 2006 and had no subjective cognitive concerns in 2008. Change in SCF scores was assessed by a 6-item questionnaire, and subjective decline was defined as new report of at least one SCF concern during follow-up.Results
Hearing loss was associated with higher risk of SCF decline. Compared with no hearing loss, the multivariable-adjusted relative risk (95% CI) of incident SCF decline was 1.30 (1.18, 1.42), 1.42 (1.26, 1.61), and 1.54 (1.22, 1.96) among men with mild, moderate, and severe hearing loss (no hearing aids), respectively (P-trend < .001). Among men with severe hearing loss who used hearing aids, the multivariable-adjusted relative risk (95% CI) was 1.37 (1.18, 1.60).Discussion
Hearing loss was associated with substantially higher risk of subsequent subjective cognitive decline in men. 相似文献10.
Elizabeth R. Mayeda M. Maria Glymour Charles P. Quesenberry Julene K. Johnson Eliseo J. Pérez-Stable Rachel A. Whitmer 《Alzheimer's & dementia》2017,13(7):761-769
Introduction
Information on anticipated survival time after dementia diagnosis among racially/ethnically diverse patients is needed to plan for care and evaluate disparities.Methods
Dementia-free health care members aged ≥64 years were followed (1/1/2000–12/31/2013) for dementia diagnosis and subsequent survival (n = 23,032 Asian American; n = 18,778 African American; n = 21,000 Latino; n = 4543 American Indian/Alaska Native; n = 206,490 white). Kaplan–Meier curves were estimated for survival after dementia diagnosis by race/ethnicity. We contrasted mortality patterns among people with versus without dementia using Cox proportional hazards models.Results
After dementia diagnosis (n = 59,494), whites had shortest median survival (3.1 years), followed by American Indian/Alaska Natives (3.4 years), African Americans (3.7 years), Latinos (4.1 years), and Asian Americans (4.4 years). Longer postdiagnosis survival among racial/ethnic minorities compared with whites persisted after adjustment for comorbidities. Racial/ethnic mortality inequalities among dementia patients mostly paralleled mortality inequalities among people without dementia.Discussion
Survival after dementia diagnosis differs by race/ethnicity, with shortest survival among whites and longest among Asian Americans. 相似文献11.
Feng Zhang Rujia Zhong Song Li Zhenfa Fu Renfei Wang Tianxiao Wang Zhili Huang Weidong Le 《Alzheimer's & dementia》2019,15(4):590-597
Objective
The present work aims to evaluate the significance of sleep disturbance and electroencephalogram (EEG) alteration in the early stage of Alzheimer's disease (AD).Background and Rationale
Sleep disturbance is common in patients with AD. It is not known if it can occur at the early stage of AD and if EEG recording may help identify the early sign of the disease.Historical Evolution
Sleep disturbance in AD has generally been considered as late consequence of the neurodegenerative process. A growing body of evidence has suggested that the sleep disturbance may occur at the early stage of AD.Updated Hypothesis
Based on the previous epidemiologic studies and our recent findings, we propose that sleep disturbance may play an important role in the development of AD. Sleep EEG changes may serve as a valuable early sign for AD in the prepathological stage.Early Experimental Data
Our data suggested that AβPPswe/PS1ΔE9 transgenic AD mice at preplaque stage (3 and 4 months of age) exhibited different profile of sleep architecture and sleep EEG, which preceded the cognitive deficit and AD neuropathology.Future Experiments and Validation Studies
Future experiments should focus on sleep EEG changes in patients with mild cognitive impairment and early stage of AD. Follow-up studies in high-risk population of the elderly are equally important. In addition, the exact molecular mechanism underlying the sleep disturbance should be thoroughly investigated.Major Challenges for the Hypothesis
Studies on human participants with early stage of AD, especially the follow-up studies on the presymptomatic elderly in a large population, are difficult and time-consuming.Linkage to Other Major Theories
Our hypothesis may link previous theories to establish a bidirectional relationship between sleep disorders and AD, which may finally form a new schematic mechanism to understand the disease pathogenesis and disease progression. 相似文献12.
Background
Recent studies have shown that neurophysiological outcomes of transcranial direct current stimulation (TDCS) are influenced by current flow in brain regions between the electrodes, and in particular the orientation of current flow relative to the cortical surface.Objective
We asked whether the directional effects of TDCS on physiological measures in the motor system would also be observed on motor behaviours.Methods
We applied TDCS during the practice of a ballistic movement task to test whether it affected learning or the retention of learning 48?h later. TDCS electrodes were oriented perpendicular to the central sulcus and two current orientations were used (posterior-anterior, TDCSPA; and anterior-posterior, TDCSAP). Transcranial magnetic stimulation (TMS) was used to assess whether changes in corticospinal excitability reflected any behavioural changes.Results
Directional TDCSAP impaired the retention of learning on the ballistic movement task compared to TDCSPA and a sham condition. Although TDCSPA had no effect on learning or retention, it blocked the typical increase in corticospinal excitability after a period of motor practice.Conclusions
Our results extend on previous reports of TDCS producing directionally specific changes in neurophysiological outcomes by showing that current direction through a cortical target also impacts upon behavioural outcomes. In addition, changes in corticospinal excitability after a period of motor practice are not causally linked to behavioural learning. 相似文献13.
Luke J. Norman Stephan F. Taylor Yanni Liu Joaquim Radua Yann Chye Stella J. De Wit Chaim Huyser F. Isik Karahanoglu Tracy Luks Dara Manoach Carol Mathews Katya Rubia Chao Suo Odile A. van den Heuvel Murat Yücel Kate Fitzgerald 《Neuropsychopharmacology》2019,85(9):713-725
Background
Error processing and inhibitory control enable the adjustment of behaviors to meet task demands. Functional magnetic resonance imaging studies report brain activation abnormalities in patients with obsessive-compulsive disorder (OCD) during both processes. However, conclusions are limited by inconsistencies in the literature and small sample sizes. Therefore, the aim here was to perform a meta-analysis of the existing literature using unthresholded statistical maps from previous studies.Methods
A voxelwise seed-based d mapping meta-analysis was performed using t-maps from studies comparing patients with OCD and healthy control subjects (HCs) during error processing and inhibitory control. For the error processing analysis, 239 patients with OCD (120 male; 79 medicated) and 229 HCs (129 male) were included, while the inhibitory control analysis included 245 patients with OCD (120 male; 91 medicated) and 239 HCs (135 male).Results
Patients with OCD, relative to HCs, showed longer inhibitory control reaction time (standardized mean difference = 0.20, p = .03, 95% confidence interval = 0.016, 0.393) and more inhibitory control errors (standardized mean difference = 0.22, p = .02, 95% confidence interval = 0.039, 0.399). In the brain, patients showed hyperactivation in the bilateral dorsal anterior cingulate cortex, supplementary motor area, and pre-supplementary motor area as well as right anterior insula/frontal operculum and anterior lateral prefrontal cortex during error processing but showed hypoactivation during inhibitory control in the rostral and ventral anterior cingulate cortices and bilateral thalamus/caudate, as well as the right anterior insula/frontal operculum, supramarginal gyrus, and medial orbitofrontal cortex (all seed-based d mapping z value >2, p < .001).Conclusions
A hyperactive error processing mechanism in conjunction with impairments in implementing inhibitory control may underlie deficits in stopping unwanted compulsive behaviors in the disorder. 相似文献14.
Kyoko Ohashi Carl M. Anderson Elizabeth A. Bolger Alaptagin Khan Cynthia E. McGreenery Martin H. Teicher 《Neuropsychopharmacology》2019,85(8):690-702
Background
Childhood maltreatment is a major risk factor for psychopathology. However, some maltreated individuals appear remarkably resilient to the psychiatric effects while manifesting the same array of brain abnormalities as maltreated individuals with psychopathology. Hence, a critical aim is to identify compensatory brain alterations that enable resilient individuals to maintain mental well-being despite alterations in stress-susceptible regions.Methods
Network models were constructed from diffusion tensor imaging and tractography in physically healthy unmedicated 18- to 25-year-old participants (N = 342, n = 192 maltreated) to develop network-based explanatory models.Results
First, we determined that susceptible and resilient individuals had the same alterations in global fiber stream network architecture using two different definitions of resilience: 1) no lifetime history of Axis I or II disorders, and 2) no clinically significant symptoms of anxiety, depression, anger-hostility, or somatization. Second, we confirmed an a priori hypothesis that right amygdala nodal efficiency was lower in asymptomatic resilient than in susceptible participants or control subjects. Third, we identified eight other nodes with reduced nodal efficiency in resilient individuals and showed that nodal efficiency moderated the relationship between maltreatment and psychopathology. Fourth, we found that models based on global network architecture and nodal efficiency could delineate group membership (control, susceptible, resilient) with 75%, 82%, and 80% cross-validated accuracy.Conclusions
Together these findings suggest that sparse fiber networks with increased small-worldness following maltreatment render individuals vulnerable to psychopathology if abnormalities occur in specific nodes, but that decreased ability of certain nodes to propagate information throughout the network mitigates the effects and leads to resilience. 相似文献15.
Dalia Khammash Molly Simmonite Thad A. Polk Stephan F. Taylor Sean K. Meehan 《Brain stimulation》2019,12(3):702-704
Background
Transcranial magnetic stimulation (TMS) is a non-invasive method to stimulate localized brain regions. Despite widespread use in motor cortex, TMS is seldom performed in sensory areas due to variable, qualitative metrics.Objective
Assess the reliability and validity of tracing phosphenes, and to investigate the stimulation parameters necessary to elicit decreased visual cortex excitability with paired-pulse TMS at short inter-stimulus intervals.Methods
Across two sessions, single and paired-pulse recruitment curves were derived by having participants outline elicited phosphenes and calculating resulting average phosphene sizes.Results
Phosphene size scaled with stimulus intensity, similar to motor cortex. Paired-pulse recruitment curves demonstrated inhibition at lower conditioning stimulus intensities than observed in motor cortex. Reliability was high across sessions.Conclusions
TMS-induced phosphenes are a valid and reliable tool for measuring cortical excitability and inhibition in early visual areas. Our results also provide appropriate stimulation parameters for measuring short-latency intracortical inhibition in visual cortex. 相似文献16.
Ali Izadi Aleksandr Pevzner Darrin J. Lee Arne D. Ekstrom Kiarash Shahlaie Gene G. Gurkoff 《Brain stimulation》2019,12(3):735-742
Background
Temporal lobe epilepsy is most prevalent among focal epilepsies, and nearly one-third of patients are refractory to pharmacological intervention. Persistent cognitive and neurobehavioral comorbidities also occur due to the recurrent nature of seizures and medication-related side effects.Hypothesis
Electrical neuromodulation is an effective strategy to reduce seizures both in animal models and clinically, but its efficacy to modulate cognition remains unclear. We hypothesized that theta frequency stimulation of the medial septum would increase septohippocampal oscillations, increase seizure threshold, and improve spatial learning in a rat model of pilocarpine-induced epilepsy.Methods
Sham and pilocarpine rats were implanted with electrodes in the medial septum, hippocampus and prefrontal cortex. EEG was assessed days prior to and following stimulation. Sham and pilocarpine-treated rats received either no stimulation, continuous (throughout each behavior), or pre-task (one minute prior to each behavior) 7.7?Hz septal stimulation during the Barnes maze spatial navigation test and also during assessment of flurothyl-induced seizures.Results
Both continuous and pre-task stimulation prevented epilepsy-associated reductions in theta oscillations over time. Additionally, both stimulation paradigms significantly improved spatial navigation in the Barnes maze, reducing latency and improving search strategy. Moreover, stimulation led to significant increases in seizure threshold in pilocarpine-treated rats. There was no evidence of cognitive enhancement or increased seizure threshold in stimulated sham rats.Conclusion
These findings have profound implications as theta stimulation of the septum represents a single frequency and target that has the potential to both improve cognition and reduce seizures for patients with refractory epilepsy. 相似文献17.
18.
Jessica B. Langbaum Jason Karlawish J. Scott Roberts Elisabeth M. Wood Angela Bradbury Nellie High Trisha L. Walsh David Gordon Raj Aggarwal Peter Davis Carter Stowell Lane Trisko Carolyn M. Langlois Eric M. Reiman Pierre N. Tariot 《Alzheimer's & dementia》2019,15(4):515-524
Introduction
Recruitment for Alzheimer's disease (AD) prevention research studies is challenging because of lack of awareness among cognitively healthy adults coupled with the high screen fail rate due to participants not having a genetic risk factor or biomarker evidence of the disease. Participant recruitment registries offer one solution for efficiently and effectively identifying, characterizing, and connecting potential eligible volunteers to studies.Methods
Individuals aged 55-75 years who live in the United States and self-report not having a diagnosis of cognitive impairment such as MCI or dementia are eligible to join GeneMatch. Participants enroll online and are provided a cheek swab kit for DNA extraction and apolipoprotein E (APOE) genotyping. Participants are not told their APOE results, although the results may be used in part to help match participants to AD prevention studies.Results
As of August 2018, 75,351 participants had joined GeneMatch. Nearly 30% of participants have one APOE4 allele, and approximately 3% have two APOE4 alleles. The percentages of APOE4 heterozygotes and homozygotes are inversely associated with age (P < .001).Discussion
GeneMatch, the first trial-independent research enrollment program designed to recruit and refer cognitively healthy adults to AD prevention studies based in part on APOE test results, provides a novel mechanism to accelerate prescreening and enrollment for AD prevention trials. 相似文献19.
C.M. Warren K.D. Tona L. Ouwerkerk J. van Paridon F. Poletiek Henk van Steenbergen J.A. Bosch S. Nieuwenhuis 《Brain stimulation》2019,12(3):635-642
Background
Transcutaneous vagus nerve stimulation (tVNS) is a new, non-invasive technique being investigated as an intervention for a variety of clinical disorders, including epilepsy and depression. It is thought to exert its therapeutic effect by increasing central norepinephrine (NE) activity, but the evidence supporting this notion is limited.Objective
In order to test for an impact of tVNS on psychophysiological and hormonal indices of noradrenergic function, we applied tVNS in concert with assessment of salivary alpha amylase (SAA) and cortisol, pupil size, and electroencephalograph (EEG) recordings.Methods
Across three experiments, we applied real and sham tVNS to 61 healthy participants while they performed a set of simple stimulus-discrimination tasks. Before and after the task, as well as during one break, participants provided saliva samples and had their pupil size recorded. EEG was recorded throughout the task. The target for tVNS was the cymba conchae, which is heavily innervated by the auricular branch of the vagus nerve. Sham stimulation was applied to the ear lobe.Results
P3 amplitude was not affected by tVNS (Experiment 1A: N?=?24; Experiment 1B: N?=?20; Bayes factor supporting null model?=?4.53), nor was pupil size (Experiment 2: N?=?16; interaction of treatment and time: p?=?.79). However, tVNS increased SAA (Experiments 1A and 2: N?=?25) and attenuated the decline of salivary cortisol compared to sham (Experiment 2: N?=?17), as indicated by significant interactions involving treatment and time (p?=?.023 and p?=?.040, respectively).Conclusion
These findings suggest that tVNS modulates hormonal indices but not psychophysiological indices of noradrenergic function. 相似文献20.
Sensen Song Anna Zilverstand Wenjun Gui Hui-jie Li Xiaolin Zhou 《Brain stimulation》2019,12(3):606-618