Cognitive impairment in older adults with epilepsy: Characterization and risk factor analysis.

OBJECTIVE: Cognitive deficits are common in epilepsy, though the impact of epilepsy on cognition in older adults is understudied. This study aimed to characterize cognition in older adults with epilepsy compared with healthy older adults and identify potential risk factors for impairment. METHODS: Thirty-eight older adults with epilepsy and 29 healthy controls completed a comprehensive neuropsychological battery, as well as measures of depression and anxiety. Chart review for current medications, seizure history, and neuroimaging was also completed. To compare cognitive performance between groups, ANOVA was used, and linear regression identified predictors of impairment among the group with epilepsy. RESULTS: Patients with epilepsy performed worse across nearly all cognitive domains, and were clinically impaired (i.e., ≥ 1.5 SD below mean) on more individual tests when compared with controls, including a subset of patients with epilepsy with normal MRIs. For all patients with epilepsy, taking a greater number of antiepileptic drugs was associated with poorer language and visuospatial abilities, and higher anxiety was associated with poorer visual memory. CONCLUSIONS: Older adults with epilepsy demonstrated greater cognitive deficits than matched controls. Polytherapy and anxiety heightened the risk for cognitive impairment in some cognitive domains, but not in others. Understanding the nature of cognitive decline in this population, as well as associated risk factors, may assist in the differential diagnosis of cognitive complaints and improve the design of treatment studies for older patients with epilepsy. Replication in larger, longitudinal studies is warranted to generalize these findings.

Ability to regulate emotion is predicted by depressive symptoms and cognitive function in a cardiac sample.

BACKGROUND: Reduced ability to regulate emotion is exhibited in depressed individuals as well as patients with neurocognitive change. Given that patients with cardiovascular disease (CVD) often exhibit both cognitive and mood changes, these could, in combination, lead to increased volatility of emotion. OBJECTIVE: The current study examined the association between ability to regulate emotion, depressive symptoms, and cognitive function in a sample of patients with CVD. METHODS: Ninety-one CVD patients referred for outpatient stress testing completed brief cognitive testing and self-report measures of emotion regulation and depressive symptoms. RESULTS: Hierarchical multiple regression analyses revealed that depressive symptoms (P < .001) and executive function (P < .05) independently contribute to emotion regulation. The interaction between these variables demonstrates that elevated depressive symptoms and decreased executive function predict increased emotion dysregulation. CONCLUSION: Findings suggest that in combination, elevated depressive symptoms and executive dysfunction contribute to poorer ability to regulate emotion in patients with CVD. Given the prevalence of depression and cognitive change in this population, these findings underscore the importance of clinician awareness of these issues in this population and suggest clinical implications for treatment of mental health issues, especially emotion regulation, in this population.

Higher serum insulin-like growth factor-1 is associated with better cognitive performance in persons with mild cognitive impairment.

BACKGROUND: Serum insulin-like growth factor-1 (IGF-1) is a mitogenic peptide involved in the regulation of cell proliferation, differentiation, and apoptosis in a wide variety of cells and tissues. Recent research suggests higher circulating levels of IGF-1 are associated with better cognitive performance in healthy older adults and in early stages of Alzheimer's disease, although the cognitive profile associated with elevated IGF-1 has not been examined in persons with mild cognitive impairment. METHODS: Thirty-one participants (age: 83.71 ± 3.59 years; 58% women) with mild cognitive impairment completed neuropsychological testing and 12-hour fasting blood draw to assess serum IGF-1. RESULTS: Partial correlations between serum IGF-1 and neuropsychological measures were conducted, adjusting for insulin, body mass index, and age. Higher IGF-1-values were associated with better global cognition (Modified Mini Mental State Exam: r = 0.39, P = 0.04) and verbal list learning (Hopkins Verbal Learning Test learning: r = 0.38, P = 0.05), Hopkins Verbal Learning Test free recall (r = 0.41, P = 0.03), and Hopkins Verbal Learning Test recognition discriminability (r = 0.46, P = 0.01). A similar trend emerged for executive function as tested by the Frontal Assessment Battery (r = 0.33, P = 0.09). CONCLUSION: Results suggest higher levels of serum IGF-1 are associated with better cognitive performance in persons with mild cognitive impairment, particularly on tests of learning and memory. These findings suggest IGF-1 may be neuroprotective not only in healthy older adults, but also in adults in the earliest stages of Alzheimer's disease. Further investigation is needed to clarify the nature of this relationship, particularly prospective studies.

Brain-derived neurotrophic factor Val66Met polymorphism and cognitive function in persons with cardiovascular disease.

AIM: Cognitive impairment is common among persons with cardiovascular disease (CVD), and several potential aetiological mechanisms have been described, including contributions of genetic markers such as variations in the brain-derived neurotrophic (BDNF) gene. This current study examined the associations of BDNF genotype with cognitive function among individuals with CVD. METHODS: This study included 110 participants with CVD who completed a comprehensive neuropsychological battery that assessed global cognitive function, attention/executive function, memory, language, and visuospatial abilities. All participants also underwent blood draw to provide a DNA sample that was used to determine BDNF genotype. Carriers of either one or two copies of the methionine allele of BDNF were categorized into one group (n = 33); non-carriers were categorized into a second group (n = 77). RESULTS: After adjustment for demographic and medical characteristics, hierarchical regression analyses revealed persons with one or more methionine alleles displayed better performance than valine/valine individuals for attention/executive function (ß = 0.22, P = 0.047) and memory (ß = 0.25, P = 0.03), as well as a trend for language (ß = 0.19, P = 0.08) and visuospatial abilities (ß = 0.21, P = 0.06). CONCLUSIONS: BDNF Val66Met had little impact on cognitive functioning in a sample of older adults with CVD, and significant findings contradicted that predicted by past work. Future work is much needed to clarify the mechanisms of these findings, particularly studies examining both circulating BDNF levels and genetic variation in the BDNF gene and cognitive function over time.

Acute cold exposure and cognitive function: evidence for sustained impairment.

Several industries experience periods of cold exposure and rewarming throughout the workday but mental performance under these conditions is unknown. A better understanding of cognition during the rewarming phase after cold exposure may help reduce accidents and improve performance. Ten young men (wearing ~0.1 clo) underwent three consecutive mornings trials where they were exposed to cold air (10°C) and then subsequently rewarmed (25°C air). A computerised test battery was administered during each stage of the protocol to determine working memory, choice reaction time, executive function and maze navigation. Rectal and skin temperature, oxygen consumption and thermal sensation were also measured throughout and showed a typical response. Relative to baseline performance, working memory, choice reaction time and executive function declined during exposure to 10°C, and these impairments persisted 60 min into the recovery period (i.e. once physiological parameters had returned to baseline). Further work is needed to develop countermeasures to this predicament. PRACTITIONER SUMMARY: This study showed that working memory, choice reaction time and executive function declined during exposure to 10°C air, and these impairments persisted 60 min into the rewarming period (i.e. once measurable physiological parameters had returned to normal). Individuals may be at risk for injury after removal from a cold environment.

Structured exercise does not stabilize cognitive function in individuals with mild cognitive impairment residing in a structured living facility.

Exercise has been shown to have positive effects on the brain and cognition in healthy older adults, though no study has directly examined possible cognitive benefits of formal exercise programs in persons with mild cognitive impairment (MCI) living in structured facilities. Thirty-one participants completed neuropsychological testing and measures of cardiovascular fitness at baseline and after 6 months of a structured exercise program that included aerobic and resistance training. While exercise improved cardiovascular fitness in persons with MCI, there was no improvement in cognitive function. Rather, MCI patients in this sample declined in performance on several tests sensitive to Alzheimer's disease. Examined in the context of past work, it appears exercise may be beneficial prior to the onset of MCI, though less helpful after its onset.

CAMTA1 T polymorphism is associated with neuropsychological test performance in older adults with cardiovascular disease.

BACKGROUND: Cardiovascular disease has long been associated with poor neurocognitive outcome, with multiple pathophysiological mechanisms that are linked to cognitive impairment in older adults. Although less frequently examined, insulin dysregulation is known to affect vascular function and the associated brain dysfunction in cardiovascular disease. Accordingly, genetic factors tied to insulin regulation may make certain people with cardiovascular disease more susceptible to cognitive dysfunction. Specifically, the calmodulin-binding transcription activator 1 (CAMTA1) genotype, which has been examined as a risk factor for Type 2 diabetes and has been linked to reduced episodic memory performance in healthy young adults, is a potential candidate gene. METHODS: Blood samples were obtained from 113 older adults with cardiovascular disease who also underwent neuropsychological testing. Carriers of either one or two copies of the T allele of CAMTA1 were categorized into one group (n = 63), whereas non-carriers were categorized into a second group (n = 50). RESULTS: Analyses showed that carriers of the T allele performed more poorly on tests of attention, executive function, and psychomotor speed, but not on tests of memory. Carriers of the T allele also performed more poorly on a measure of global cognitive function. CONCLUSIONS: Results indicate that CAMTA1 genotype is associated with cognitive function in older adults with cardiovascular disease, because carriers of the T allele performed more poorly on tests of attention, executive function, and psychomotor speed. Contrary to expectations, there were no differences in memory performance among carriers and non-carriers of the T allele. Given these mixed findings, further studies are necessary to elucidate the association between CAMTA1 and cognition, particularly gene expression and neuroimaging studies.

Effects of cholinesterase inhibitors on visual attention in drivers with Alzheimer disease.

OBJECTIVE: We conducted a combined observational cohort and case-control study in patients with Alzheimer disease (AD) to assess the effects of acetylcholinesterase inhibitor (ChEI) treatment on cognitive functions important for driving. METHODS: Performance of 24 outpatients with newly diagnosed (untreated) early-stage AD was compared before beginning ChEI (pre-ChEI) and after 3 months of therapy (post-ChEI) on a set of computerized tests of visual attention and executive function administered under both single-task and dual-task conditions. To address the limitation of a lack of an untreated control group in this observational cohort study, performance of 35 outpatients with newly diagnosed (untreated) early-stage AD (ChEI nonusers) were also compared with a demographically matched group of AD patients treated with stable doses of a ChEI (ChEI users) on these tasks. RESULTS: Performance was consistently worse under dual-task than single-task conditions regardless of ChEI treatment status. However, ChEI treatment consistently affected specific components of attention within each test across both sets of comparisons: ChEI treatment enhanced simulated driving accuracy and was associated with significantly better visual search target detection accuracy and response time in both pre-ChEI-post-ChEI and users-nonusers treatment comparisons. Cholinesterase inhibitor treatment also improved overall time to complete a set of mazes while not affecting accuracy of completion. CONCLUSIONS: Cholinesterase inhibitor treatment was associated with improvements in tests of executive function and visual attention. These findings could have important implications for patients who continue to drive in the early stages of AD.

Bariatric surgery patients exhibit improved memory function 12 months postoperatively.

BACKGROUND: Previous work from our group demonstrated improved memory function in bariatric surgery patients at 12 weeks postoperatively relative to controls. However, no study has examined longer-term changes in cognitive functioning following bariatric surgery. METHODS: A total of 137 individuals (95 bariatric surgery patients and 42 obese controls) were followed prospectively to determine whether postsurgery cognitive improvements persist. Potential mechanisms of change were also examined. Bariatric surgery participants completed self-report measurements and a computerized cognitive test battery prior to surgery and at 12-week and 12-month follow-up; obese controls completed measures at equivalent time points. RESULTS: Bariatric surgery patients exhibited cognitive deficits relative to well-established standardized normative data prior to surgery, and obese controls demonstrated similar deficits. Analyses of longitudinal change indicated an interactive effect on memory indices, with bariatric surgery patients demonstrating better performance postoperatively than obese controls. CONCLUSIONS: While memory performance was improved 12 months postbariatric surgery, the mechanisms underlying these improvements were unclear and did not appear attributable to obvious postsurgical changes, such as reductions in body mass index or comorbid medical conditions. Future studies employing neuroimaging, metabolic biomarkers, and more precise physiological measurements are needed to determine the mechanisms underlying memory improvements following bariatric surgery.

Cognitive function predicts weight loss after bariatric surgery.

BACKGROUND: Clinically significant cognitive impairment is found in a subset of patients undergoing bariatric surgery. These difficulties could contribute to a reduced adherence to postoperative lifestyle changes and decreased weight loss. The present study is the first to prospectively examine the independent contribution of cognitive function to weight loss after bariatric surgery. Executive function/attention and verbal memory at baseline were expected to negatively predict the percentage of excess weight loss (%EWL) and body mass index (BMI) at follow-up. Three sites of the Longitudinal Assessment of Bariatric Surgery parent project were used: Columbia (New York, NY), Cornell (Princeton, NJ), and the Neuropsychiatric Research Institute (Fargo, ND). METHODS: A total of 84 individuals enrolled in the Longitudinal Assessment of Bariatric Surgery project undergoing bariatric surgery completed a cognitive evaluation at baseline. The BMI and %EWL were calculated at the 12-week and 12-month postoperative follow-up visits. RESULTS: Clinical impairment in task performance was most prominent in tasks associated with verbal recall and recognition (14.3-15.5% of the sample) and perseverative errors (15.5%). After accounting for demographic and medical variables, the baseline test results of attention/executive function and memory predicted the BMI and %EWL at 12 months but not at 12 weeks. CONCLUSIONS: These results have demonstrated that baseline cognition predicts for greater %EWL and lower BMI 12 months after bariatric surgery. Additional work is needed to clarify the degree to which cognition contributes to adherence and the potential mediation of cognition on the relationship between adherence and weight loss in this group.

Road test and naturalistic driving performance in healthy and cognitively impaired older adults: does environment matter?

OBJECTIVES: To relate the standardized road test to video recordings of naturalistic driving in older adults with a range of cognitive impairment. DESIGN: Cross-sectional observational study. SETTING: Academic medical center memory disorders clinic. PARTICIPANTS: One hundred three older drivers (44 healthy, 59 with cognitive impairment) who passed a road test. MEASUREMENTS: Error rate and global ratings of safety (pass with and without recommendations, marginal with restrictions or training, or fail) made by a professional driving instructor. RESULTS: There was fair agreement between global ratings on the road test and naturalistic driving. More errors were detected in the naturalistic environment, but this did not affect global ratings. Error scores between settings were significantly correlated, and the types of errors made were similar. History of crashes corrected for miles driven per week was related to road test error scores but not naturalistic driving error scores. Global cognition (Mini-Mental State Examination) was correlated with road test and naturalistic driving errors. In healthy older adults, younger age was correlated with fewer errors on the road test and more errors in naturalistic driving. CONCLUSION: Road test performance is a reasonable proxy for estimating fitness to drive in older individuals' typical driving environments, but differences between performance assessed using these two methods remain poorly understood and deserve further study.

Both texting and eating are associated with impaired simulated driving performance.

OBJECTIVE: Distracted driving is a known contributor to traffic accidents, and many states have banned texting while driving. However, little is known about the potential accident risk of other common activities while driving, such as eating. The objective of the current study was to examine the adverse impact of eating/drinking behavior relative to texting and nondistracted behaviors on a simulated driving task. METHODS: A total of 186 participants were recruited from undergraduate psychology courses over 2 semesters at Kent State University. We utilized the Kent Multidimensional Assessment Driving Simulation (K-MADS) to compare simulated driving performance among participants randomly assigned to texting (N = 45), eating (N = 45), and control (N = 96) conditions. Multivariate analyses of variance (MANOVA) were conducted to examine between-group differences on simulated driving indices. RESULTS: MANOVA analyses indicated that groups differed in simulated driving performance, F(14, 366) = 7.70, P < .001. Both texting and eating produced impaired driving performance relative to controls, though these behaviors had approximately equal effect. Specifically, both texting and eating groups had more collisions, pedestrian strikes, and center line crossings than controls. In addition, the texting group had more road edge excursions than either eating or control participants and the eating group missed more stop signs than controls. CONCLUSIONS: These findings suggest that both texting and eating are associated with poorer simulated driving performance. Future work is needed to determine whether these findings generalize to real-world driving and the development of strategies to reduce distracted driving.

Cognitive profiles in heart failure: a cluster analytic approach.

Cognitive impairment is common among individuals with heart failure (HF), but the exact nature of these impairments remains unclear. The current study examined 140 older adults with heart failure and sought to determine whether there are distinct cognitive profiles using a cluster analytic approach. Results indicated three unique profiles comprising individuals who were cognitively intact, memory impaired, and globally impaired. Clusters differed on several important demographic and clinical characteristics. These findings suggest that cognitive impairment in persons with HF is more heterogeneous than commonly believed and has important implications for treatment recommendations.