Background:Concussed patients have impaired reaction time(RT)and cognition following injury that may linger and impair driving performance.Limited research has used direct methods to assess driving-RT post-concussion....Background:Concussed patients have impaired reaction time(RT)and cognition following injury that may linger and impair driving performance.Limited research has used direct methods to assess driving-RT post-concussion.Our study compared driving RT during simulated scenarios between concussed and control individuals and examined driving-RT’s relationship with traditional computerized neurocognitive testing(CNT)domains.Methods:We employed a cross-sectional study among 14 concussed(15.9±9.8 days post-concussion,mean±SD)individuals and 14 healthy controls matched for age,sex,and driving experience.Participants completed a driving simulator and CNT(CNS Vital Signs)assessment within 48 h of symptom resolution.A driving-RT composite(ms)was derived from 3 simulated driving scenarios:stoplight(green to yellow),evasion(avoiding approaching vehicle),and pedestrian(person running in front of vehicle).The CNT domains included verbal and visual memory;CNT-RT(simple-,complex-,Stroop-RT individually);simple and complex attention;motor,psychomotor,and processing speed;executive function;and cognitive flexibility.Independent t tests and Hedge d effect sizes assessed driving-RT differences between groups,Pearson correlations(r)examined driving RT and CNT domain relationships among cohorts separately,and p values were controlled for false discovery rate via Benjamini-Hochberg procedures(a=0.05).Results:Concussed participants demonstrated slower driving-RT composite scores than controls(mean difference=292.86 ms;95%confidence interval(95%CI):70.18515.54;p=0.023;d=0.992).Evasion-RT(p=0.054;d=0.806),pedestrian-RT(p=0.258;d=0.312),and stoplight-RT(p=0.292;d=0.585)outcomes were not statistically significant after false-discovery rate corrections but demonstrated medium to large effect sizes for concussed deficits.Among concussed individuals,driving-RT outcomes did not significantly correlate with CNT domains(r-range:0.51 to 0.55;p>0.05).No correlations existed between driving-RT outcomes and CNT domains among control participants either(r-range:0.52 to 0.72;p>0.05).Conclusion:Slowed driving-RT composite scores and large effect sizes among concussed individuals when asymptomatic signify lingering impairment and raise driving-safety concerns.Driving-RT and CNT-RT measures correlated moderately but not statistically,which indicates that CNT-RT is not an optimal surrogate for driving RT.展开更多
Background: Although growing evidence links beta-amyloid (Aβ) and neuronal hyperexcitability in preclinical mouse models of Alzheimer’s disease (AD), a similar association in humans is yet to be established. The fir...Background: Although growing evidence links beta-amyloid (Aβ) and neuronal hyperexcitability in preclinical mouse models of Alzheimer’s disease (AD), a similar association in humans is yet to be established. The first aim of the study was to determine the association between elevated Aβ (Aβ+) and cognitive processes measured by the P3 event-related potential (ERP) in cognitively normal (CN) older adults. The second aim was to compare the event- related power between CNAβ+ and CNAβ−. Methods: Seventeen CNAβ+ participants (age: 73 ± 5, 11 females, Montreal Cognitive Assessment [MoCA] score 26 ± 2) and 17 CNAβ- participants group-matched for age, sex, and MOCA completed a working memory task (n-back with n = 0, 1, 2) test while wearing a 256-channel electro-encephalography net. P3 peak amplitude and latency of the target, nontarget and task difference effect (nontarget−target), and event-related power in the delta, theta, alpha, and beta bands, extracted from Fz, Cz, and Pz, were compared between groups using linear mixed models. P3 ampli-tude of the task difference effect at Fz and event-related power in the delta band were considered main outcomes. Correlations of mean Aβ standard uptake value ratios (SUVR) using positron emission tomography with P3 amplitude and latency of the task difference effect were analyzed using Pearson Correlation Coefficient r. Results: The P3 peak amplitude of the task difference effect at Fz was lower in the CNAβ+ group (P = 0.048). Simi-larly, power was lower in the delta band for nontargets at Fz in the CNAβ+ participants (P = 0.04). The CNAβ+ partici-pants also demonstrated higher theta and alpha power in channels at Cz and Pz, but no changes in P3 ERP. Strong correlations were found between the mean Aβ SUVR and the latency of the 1-back (r = − 0.69;P = 0.003) and 2-back (r = − 0.69;P = 0.004) of the task difference effect at channel Fz in the CNAβ+ group. Conclusions: Our data suggest that the elevated amyloid in cognitively normal older adults is associated with neuronal hyperexcitability. The decreased P3 task difference likely reflects early impairments in working memory processes. Further research is warranted to determine the validity of ERP in predicting clinical, neurobiological, and functional manifestations of AD.展开更多
基金the Office of the Vice President of Research at the University of Georgia.
文摘Background:Concussed patients have impaired reaction time(RT)and cognition following injury that may linger and impair driving performance.Limited research has used direct methods to assess driving-RT post-concussion.Our study compared driving RT during simulated scenarios between concussed and control individuals and examined driving-RT’s relationship with traditional computerized neurocognitive testing(CNT)domains.Methods:We employed a cross-sectional study among 14 concussed(15.9±9.8 days post-concussion,mean±SD)individuals and 14 healthy controls matched for age,sex,and driving experience.Participants completed a driving simulator and CNT(CNS Vital Signs)assessment within 48 h of symptom resolution.A driving-RT composite(ms)was derived from 3 simulated driving scenarios:stoplight(green to yellow),evasion(avoiding approaching vehicle),and pedestrian(person running in front of vehicle).The CNT domains included verbal and visual memory;CNT-RT(simple-,complex-,Stroop-RT individually);simple and complex attention;motor,psychomotor,and processing speed;executive function;and cognitive flexibility.Independent t tests and Hedge d effect sizes assessed driving-RT differences between groups,Pearson correlations(r)examined driving RT and CNT domain relationships among cohorts separately,and p values were controlled for false discovery rate via Benjamini-Hochberg procedures(a=0.05).Results:Concussed participants demonstrated slower driving-RT composite scores than controls(mean difference=292.86 ms;95%confidence interval(95%CI):70.18515.54;p=0.023;d=0.992).Evasion-RT(p=0.054;d=0.806),pedestrian-RT(p=0.258;d=0.312),and stoplight-RT(p=0.292;d=0.585)outcomes were not statistically significant after false-discovery rate corrections but demonstrated medium to large effect sizes for concussed deficits.Among concussed individuals,driving-RT outcomes did not significantly correlate with CNT domains(r-range:0.51 to 0.55;p>0.05).No correlations existed between driving-RT outcomes and CNT domains among control participants either(r-range:0.52 to 0.72;p>0.05).Conclusion:Slowed driving-RT composite scores and large effect sizes among concussed individuals when asymptomatic signify lingering impairment and raise driving-safety concerns.Driving-RT and CNT-RT measures correlated moderately but not statistically,which indicates that CNT-RT is not an optimal surrogate for driving RT.
基金the National Institute on Aging of the National Institutes of Health under Award Number K01 AG058785This study was supported in part by a pilot grant of the KU Alzheimer Disease Center(P30 AG035982).
文摘Background: Although growing evidence links beta-amyloid (Aβ) and neuronal hyperexcitability in preclinical mouse models of Alzheimer’s disease (AD), a similar association in humans is yet to be established. The first aim of the study was to determine the association between elevated Aβ (Aβ+) and cognitive processes measured by the P3 event-related potential (ERP) in cognitively normal (CN) older adults. The second aim was to compare the event- related power between CNAβ+ and CNAβ−. Methods: Seventeen CNAβ+ participants (age: 73 ± 5, 11 females, Montreal Cognitive Assessment [MoCA] score 26 ± 2) and 17 CNAβ- participants group-matched for age, sex, and MOCA completed a working memory task (n-back with n = 0, 1, 2) test while wearing a 256-channel electro-encephalography net. P3 peak amplitude and latency of the target, nontarget and task difference effect (nontarget−target), and event-related power in the delta, theta, alpha, and beta bands, extracted from Fz, Cz, and Pz, were compared between groups using linear mixed models. P3 ampli-tude of the task difference effect at Fz and event-related power in the delta band were considered main outcomes. Correlations of mean Aβ standard uptake value ratios (SUVR) using positron emission tomography with P3 amplitude and latency of the task difference effect were analyzed using Pearson Correlation Coefficient r. Results: The P3 peak amplitude of the task difference effect at Fz was lower in the CNAβ+ group (P = 0.048). Simi-larly, power was lower in the delta band for nontargets at Fz in the CNAβ+ participants (P = 0.04). The CNAβ+ partici-pants also demonstrated higher theta and alpha power in channels at Cz and Pz, but no changes in P3 ERP. Strong correlations were found between the mean Aβ SUVR and the latency of the 1-back (r = − 0.69;P = 0.003) and 2-back (r = − 0.69;P = 0.004) of the task difference effect at channel Fz in the CNAβ+ group. Conclusions: Our data suggest that the elevated amyloid in cognitively normal older adults is associated with neuronal hyperexcitability. The decreased P3 task difference likely reflects early impairments in working memory processes. Further research is warranted to determine the validity of ERP in predicting clinical, neurobiological, and functional manifestations of AD.
