Sex differences in cognition in healthy elderly individuals

Sex-Differences in Health-Related Characteristics of Senior Center Users: The VERISAÚDE Study

Background

We explored sex-related differences in sociodemographic, medical, psychological, and functional conditions in older adults attending to senior citizens’ centers.

Materials and Methods

An exploratory study was conducted as part of the VERISAÚDE project, a cross-sectional population-based study of individuals aged ≥65 years enrolled in senior community centers located in Galicia, Northwest of Spain (n = 749). A comprehensive gerontological evaluation was used to assess the social, medical, psychological, and functional characteristics of the sample.

Results

Women presented a higher prevalence of frailty (p = 0.017), a higher risk of malnutrition (p = 0.029), more medication consumption (p = 0.002), and polypharmacy (p = 0.008), higher depressive scores (p = 0.007), and lower cognitive scores (p = 0.045) than men, who showed a higher prevalence of hearing impairment (p = 0.034), toxic habits (all ps = 0.0001), and comorbidity (p = 0.002), and better quality of life (p = 0.030), and social resources (p = 0.002). Participants considered that attending and being involved in senior centers has a positive influence on their health and promotes successful aging.

Discussion

Important differences were found between women and men in health variables, suggesting that sex exerts a powerful influence on health status in older age. These differences should be identified and taking into account when designing interventions to promote active aging and to improve the quality of life of older adults. Taking a sex perspective during the evaluation process could lead to a higher number of older people being effectively treated in clinical practice.

Demographically-adjusted norms for selected tests of verbal fluency: Results from the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project

OBJECTIVE

Verbal fluency tests are sensitive to various disorders affecting the central nervous system and are commonly included in neuropsychological evaluations. We aimed to develop normative data for two verbal fluency tests in a sample of native Spanish-speakers living in the US-Mexico border region.

METHOD

Participants included 254 adults from the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) Project (Age: range = 19-60; Education: range = 0-20, 59% female). Participants completed two verbal fluency tests (i.e., letter [PMR] and semantic/category fluency [Animal Naming]) as part of a larger neuropsychological test battery. We examined linear and nonlinear effects of demographic factors (age, education, and gender) on verbal fluency raw scores, and developed T-scores using fractional polynomial equations controlling for demographics. We also calculated the rates of "impairment" (T-scores < 40) that would be obtained by applying the newly developed norms and available norms for non-Hispanic English-speakers on comparable tests.

RESULTS

There were positive small effects of age and medium effects of education on verbal fluency raw scores. The normalized distribution of T-scores with the new norms showed expected psychometric properties. However, rates of impairment for both letter and semantic fluency were significantly higher when applying non-Hispanic White norms, and significantly lower when applying non-Hispanic Black norms.

CONCLUSIONS

We provide norms for Spanish-speakers living along the US-Mexico border region for two verbal fluency tests that are co-normed with a more extensive neuropsychological battery. These regional norms will improve interpretation of verbal fluency test performance in Spanish-speakers living in the US-Mexico borderland.

Sex Differences in Verbal Fluency Among Young Adults

Verbal fluency tasks have been used as tools to measure various cognitive processes, such as executive functions, memory, and language. Sex differences in verbal fluency performance have been mostly investigated in population studies. Little of this research has focused on young adults. The goal of this study was to assess the impact of sex and task category on word production and verbal strategies (i.e., cluster size and switches) in young adults. The phonemic (letter “k”, letter “f”) and semantic (animals, fruits, sharp objects) fluency measures were used. Men and women were compared in terms of the number of produced words and the use of verbal strategies (number of switches and mean cluster size controlled for produced words). Results revealed subtle sex differences in verbal fluency in young adults. Men performed slightly better in semantic fluency, producing more words, while there were no sex differences in verbal strategies. There were also no sex differences in word production and verbal strategies in the phonemic fluency tasks. Furthermore, there were differences in the number of produced words, mean cluster sizes, and switches between semantic tasks as well as between phonemic tasks. These results can be interpreted in the context of potential differences in mental lexicon and social roles. Moreover, our results suggest that assessment of verbal strategies and overall word production may be important in the context of sex differences in verbal fluency among young adults as well as in neuropsychological diagnosis

Sex Differences in Cognitive Changes in De Novo Parkinson's Disease

OBJECTIVE

To evaluate the sex differences in cognitive course over 4 years in Parkinson's disease (PD) patients with and without mild cognitive impairment (MCI) compared to controls.

METHODS

Four-year longitudinal cognitive scores of 257 cognitively intact PD, 167 PD-MCI, and 140 controls from the Parkinson's Progression Markers Initiative were included. Longitudinal scores of men and women, and PD with and without MCI were compared.

RESULTS

Women had better verbal memory, men had better visuospatial function. There was no interaction between sex, diagnostic group, and/or time (4-year follow-up period).

CONCLUSIONS

Sex differences in cognitive course in de novo PD are similar to healthy aging. Cognitive decline rates in PD with and without MCI are similar for the first 4 years of PD.

Characterization of cognition in mild cognitive impairment with and without Parkinson's disease

•

Screening tests can diagnose PD-MCI but do not give detailed cognitive profiles.

•

Criteria based on a complete neuropsychological battery identify more PD patients with MCI.

•

The overall cognitive profile is similar in PD-MCI and MCI.

•

Neuropsychological batteries and definition of impairment cut-offs should be refined.

Inter-relationships between Gender, Frailty and 10-Year Survival in Older Italian Adults: an observational longitudinal study

Aim of the present study was to assess the impact of gender on the relationship between long-term mortality and clinical frailty. In an observational, longitudinal study on 10-year mortality, we examined 1284 subjects. The Frailty Staging System was used to assess frailty. The Cox model was employed to assess variables independently associated with survival using a backward stepwise algorithm. To investigate the possible interactions between gender and the selected variables, an extension of the multivariable fractional polynomial algorithm was adopted. Women were more likely to be older, have a higher disability, present with more comorbidities, consume more drugs, be frail and have a higher rate of survival at the follow-up than were men. At the Cox multivariate analysis only age (HR 2.26), female gender (HR 0.43), and number of drugs (HR 1.57) were significant and independent factors associated with all-cause mortality. In the survival analyses, only frailty (vs no frailty) showed significant interaction with gender (p < 0.001, HR = 1.92). While the presence of frailty reduced the survival rate in women, no effect was observed in men. Importantly, frail women showed higher survival rates than did both frail and no frail men. The main finding of the present study is that gender shapes up the association between frailty and long-term survival rates.

Neural Efficiency of Human-Robotic Feedback Modalities Under Stress Differs With Gender

Sensory feedback, which can be presented in different modalities - single and combined, aids task performance in human-robotic interaction (HRI). However, combining feedback modalities does not always lead to optimal performance. Indeed, it is not known how feedback modalities affect operator performance under stress. Furthermore, there is limited information on how feedback affects neural processes differently for males and females and under stress. This is a critical gap in the literature, particularly in the domain of surgical robotics, where surgeons are under challenging socio-technical environments that burden them physiologically. In the present study, we posited operator performance as the summation of task performance and neurophysiological cost of maintaining that performance. In a within-subject design, we used functional near-infrared spectroscopy to assess cerebral activations of 12 participants who underwent a 3D manipulation task within a virtual environment with concurrent feedback (visual and visual + haptic) in the presence and absence of a cognitive stressor. Cognitive stress was induced with the serial-7 subtraction test. We found that while task performance was higher with visual than visual + haptic feedback, it degraded under stress. The two feedback modalities were found to be associated with varying neural activities and neural efficiencies, and these were stress- and gender-dependent. Our findings engender further investigation into effectiveness of feedback modalities on males and females under stressful conditions in HRI.

Sex Differences in Cognitive Flexibility and Resting Brain Networks in Middle-Aged Marmosets

Sex differences in human cognitive performance are well characterized. However, the neural correlates of these differences remain elusive. This issue may be clarified using nonhuman primates, for which sociocultural influences are minimized. We used the marmoset (Callithrix jacchus) to investigate sex differences in two aspects of executive function: reversal learning and intradimensional/extradimensional (ID/ED) set shifting. Stress reactivity and motor function were also assessed. In agreement with human literature, females needed more trials than males to acquire the reversals. No sex differences in ED set shifting or motivational measures were observed. The findings suggest enhanced habit formation in females, perhaps due to striatal estrogenic effects. Both sexes showed increased urinary cortisol during social separation stressor, but females showed an earlier increase in cortisol and a greater increase in agitated locomotion, possibly indicating enhanced stress reactivity. Independent of sex, basal cortisol predicted cognitive performance. No sex differences were found in motor performance. Associations between brain networks and reversal learning performance were investigated using resting state fMRI. Resting state functional connectivity (rsFC) analyses revealed sex differences in cognitive networks, with differences in overall neural network metrics and specific regions, including the prefrontal cortex, caudate, putamen, and nucleus accumbens. Correlations between cognitive flexibility and neural connectivity indicate that sex differences in cognitive flexibility are related to sex-dependent patterns of resting brain networks. Overall, our findings reveal sex differences in reversal learning, brain networks, and their relationship in the marmoset, positioning this species as an excellent model to investigate the biological basis of cognitive sex differences.

Sex Moderates the Impact of Diagnosis and Amyloid PET Positivity on Hippocampal Subfield Volume

We examined moderation effects of sex and diagnosis on the effect of positive florbetapir positron emission tomography (PET) amyloid-β (Aβ) scan (A+) on hippocampus subfield volumes in 526 normal control (NC) and early mild cognitive impairment (eMCI) participants from the Alzheimer’s Disease Neuroimaging Initiative (ADNI2; ADNI-GO). Regression moderation models showed that women— but not men— with NC designation did not show reduced subiculum volumes despite A+. At the eMCI stage, A+ was detrimental across sexes. Findings were significant while accounting for the effects of age, cognition at screening, education, and APOE4 carrier status. These findings suggest that women with A+ have early neural resistance to Alzheimer’s disease-related amyloid burden.

Sex differences in the association between amyloid and longitudinal brain volume change in cognitively normal older adults

Objective

Amyloid positivity is a biomarker of AD pathology, yet the associations between amyloid positivity and brain volumetric changes, especially in the hippocampus, are inconsistent. We hypothesize that sex differences in associations may contribute to inconsistent findings among cognitively normal older adults.

Methods

Using linear mixed effects models, we examined the association of amyloid positivity with prospective volumetric changes (mean = 3.3 visits) of parahippocampal gyrus (phg), hippocampus, entorhinal cortex (erc), precuneus, and fusiform gyrus among 171 Baltimore Longitudinal Study of Aging participants aged ≥55 years. Amyloid positivity was defined by a mean ¹¹C-Pittsburgh Compound B (PiB) distribution volume ratio (DVR) cut-off of 1.062. All analyses included age, race, sex, education, APOE e4 carrier status, and two-way interactions of these covariates with time. Two-way interaction between sex and PiB+/− status and three-way interaction of sex and PiB+/− status with time were added to assess whether sex modified associations.

Results

PiB+ status was associated with greater volumetric declines in the phg (β = −0.036, SE = 0.011, p = 0.001) and erc (β = −0.019, SE = 0.009, p = 0.045). Sex modified the association of PiB+ status and rates of volumetric declines in fusiform (β = −0.117, SE = 0.049, p = 0.019). PiB+ males had steeper rates of volumetric declines in phg (β = −0.051, SE = 0.013, p < 0.001) and erc (β = −0.029, SE = 0.012, p = 0.014) than PiB- males, while there was no difference in rates of volumetric change between PiB+ and PiB- females.

Conclusions

Amyloidosis is a marker of entorhinal and parahippocampal volume loss. Amyloid positivity is a predictor of volume loss in brain regions affected by early AD pathology in men, but not women.

•

Amyloid positivity is related to volume loss in regions of early AD pathology.

•

Sex modified the association of amyloid positivity and brain volumetric changes.

•

Amyloid-positive males were vulnerable to volume loss in regions of early AD.

•

Females with and without amyloid positivity had similar volume changes.

The Modulatory Effect of Gender and Cytomegalovirus-Seropositivity on Circulating Inflammatory Factors and Cognitive Performance in Elderly Individuals

Aging is characterized by a chronic increase in the systemic levels of inflammatory cytokines even in ostensibly healthy individuals. The drivers of age-related increase in systemic inflammation are unclear but one potential contributor may be a persistent infection with Cytomegalovirus (CMV). In this study, we characterized the inflammatory status of 161 older participants recruited to undergo a six-month training intervention. We investigated the influence of gender and CMV-seropositivity on the main inflammatory and anti-inflammatory circulating biomarkers, such as cytokines, receptor antagonist, soluble receptor, immune cells, and relevant metabolic markers. We found that both gender and CMV-seropositivity modulate circulating peripheral biomarkers, and that CMV-infection modifies associations among the latter. Moreover, we observed an interaction between CMV-serostatus and gender associations with cognitive abilities: gender differences in fluid intelligence (Gf) and working memory (WM) were noted only in CMV-negative individuals. Finally, we found that in the CMV-seronegative participants Gf, episodic memory (EM), and WM correlated negatively with pro-inflammatory tumor necrosis factor (TNF); and EM correlated positively with anti-inflammatory interleukin (IL)-10. In CMV-seropositive individuals EM and Gf correlated negatively with pro-inflammatory IL-6, while EM, Gf, and WM correlated negatively with anti-inflammatory IL-1RA. We conclude that both CMV-serostatus and gender may modulate neuroimmune factors, cognitive performance and the relationship between the two domains and should therefore be considered in comparative and interventional studies with elderly people.

A Repeated Measures Pilot Comparison of Trajectories of Fluctuating Endogenous Hormones in Young Women with Traumatic Brain Injury, Healthy Controls

Objective

To compare baseline and 72-hour hormone levels in women with traumatic brain injury (TBI) and controls.

Setting

Hospital emergency department.

Participants

21 women ages 18-35 with TBI and 21 controls.

Design

Repeated measures.

Main Measures

Serum samples at baseline and 72 hours; immunoassays for estradiol (E2), progesterone (PRO), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and cortisol (CORT); and health history.

Results

Women with TBI had lower E2 (p = 0.042) and higher CORT (p = 0.028) levels over time. Lower Glasgow Coma Scale (GSC) and OCs were associated with lower FSH (GCS p = 0.021; OCs p = 0.016) and higher CORT (GCS p = 0.001; OCs p = 0.008).

Conclusion

Acute TBI may suppress E2 and increase CORT in young women. OCs appeared to independently affect CORT and FSH responses. Future work is needed with a larger sample to characterize TBI effects on women's endogenous hormone response to injury and OC use's effects on post-TBI stress response and gonadal function, as well as secondary injury.

Influence of sex differences in interpreting learning and memory within a clinical sample of older adults

Sex is an important factor to consider when evaluating memory with older adults. This present study aimed to examine sex differences in memory within a clinical sample of older adults (N = 1084). Raw learning and recall scores on the Hopkins Verbal Learning Test, Revised (HVLT-R) and Brief Visuospatial Memory Test, Revised (BVMT-R) were compared between sexes within the entire sample and cohorts stratified by age. Within the entire sample, women outperformed men in HVLT-R learning and recall, and there were no sex differences in BVMT-R performance. These sex differences, however, were absent or reversed for those with impaired HVLT-R performance and functional deficits, indicating that women retain an early advantage in verbal memory, which is lost with greater indication of disease severity. These findings indicate that women retain an advantage in verbal learning and memory, at least before significant levels of impairment, within a sample of older adults seen at an outpatient neurology clinic, which may have implications for diagnosing memory disorders.

Links Between Metabolic and Structural Changes in the Brain of Cognitively Normal Older Adults: A 4-Year Longitudinal Follow-Up

We aimed to longitudinally assess the relationship between changing brain energy metabolism (glucose and acetoacetate) and cognition during healthy aging. Participants aged 71 ± 5 year underwent cognitive evaluation and quantitative positron emission tomography (PET) and magnetic resonance imaging (MRI) scans at baseline (N = 25) and two (N = 25) and four (N = 16) years later. During the follow-up, the rate constant for brain extraction of glucose (K_glc) declined by 6%–12% mainly in the temporo-parietal lobes and cingulate gyri (p ≤ 0.05), whereas brain acetoacetate extraction (Kacac) and utilization remained unchanged in all brain regions (p ≥ 0.06). Over the 4 years, cognitive results remained within the normal age range but an age-related decline was observed in processing speed. K_glc in the caudate was directly related to performance on several cognitive tests (r = +0.41 to +0.43, allp ≤ 0.04). Peripheral insulin resistance assessed by the homeostasis model assessment of insulin resistance (HOMA-IR) was significantly inversely related to K_glc in the thalamus (r = −0.44, p = 0.04) and in the caudate (r = −0.43, p = 0.05), and also inversely related to executive function, attention and processing speed (r = −0.45 to −0.53, all p ≤ 0.03). We confirm in a longitudinal setting that the age-related decline in K_glc is directly associated with declining performance on some tests of cognition but does not significantly affect Kacac.

Associated factors for cognition of physically independent elderly people living in residential care facilities for the aged in Sri Lanka

BACKGROUND

As the elderly population and prevalence of dementia is increasing, it is necessary to have a better comprehension of the influence of specific factors on cognitive function. Dementia is not an inevitable consequence of ageing. Lifestyle factors might either increase or decrease the risk. Even though different studies have focused on individual factors, only a few studies are available which assess all these factors as a whole. Available evidence on these factors is mainly from high income countries and much less evidence is available from low and middle income countries. As cognition is critical for elderly people to engage in a physically independent life, we aimed to identify the associated factors of cognition.

METHODS

This was a descriptive cross sectional study performed with 421 elderly people dwelling in residential care facilities for the aged in two selected districts in the Southern Province of Sri Lanka. Cognition was assessed using the Mini Mental State Examination (MMSE). Independent sample t test, ANOVA and regression analyses were used to explore associated factors for cognition. The statistical significance was kept at bonferroni adjusted p < 0.004.

RESULTS

The study included elderly people with a mean age of 71.9 ± 6.7 years and of them 65.8% were females. Factors affecting higher level of cognition were, having upper secondary, advanced and higher education; being married; arriving at the facility on one's own accord; being visited by family members; higher physical activity levels and engaging in social and leisure activities (p < 0.004). The factors, namely physical activity level, educational status, visits by family members and engaging in leisure activities were the predictors of cognition in the regression model.

CONCLUSION

Though there were several factors that associated with the level of cognition such as educational status, marital status, reason for attending the facility, visits by family members, physical activity levels and participation in social and leisure activities, only the factors, such as physical activity levels, visits by family members, educational status and engaging in leisure activities were the predictors of cognition.

Exploration of Major Cognitive Deficits in Medication-Free Patients With Major Depressive Disorder

Background: Major depressive disorder (MDD) is associated with a wide range of cognitive deficits. However, it remains unclear whether there will be a major cognitive deficit independently caused by depression at acute episodes of MDD. Method: A comprehensive neurocognitive test battery was used to assess the executive function, processing speed, attention, and memory in 162 MDD patients and 142 healthy controls (HCs). A multivariate analysis of variance, hierarchical regression analyses and general linear regression analyses were used to explore the possible major cognitive deficits and their predictor variables. Results: MDD patients showed extensive impairment in all four cognitive domains. Impairment of executive function and processing speed were found to persist even with other cognitive domains and clinical variables being accounted for. Executive function and processing speed were further predicted by total disease duration and depression severity, respectively. Conclusions: Executive function and processing speed may be two distinct major deficits at acute episodes of MDD. Furthermore, the executive function is likely originated from the cumulative effect of disease duration and processing speed is possibly derived from the temporary effect of current depressive episode.

Can we predict cognitive decline after initial diagnosis of multiple sclerosis? Results from the German National early MS cohort (KKNMS)

BACKGROUND

Cognitive impairment (CI) affects approximately one-third of the patients with early multiple sclerosis (MS) and clinically isolated syndrome (CIS). Little is known about factors predicting CI and progression after initial diagnosis.

METHODS

Neuropsychological screening data from baseline and 1-year follow-up of a prospective multicenter cohort study (NationMS) involving 1123 patients with newly diagnosed MS or CIS were analyzed. Employing linear multilevel models, we investigated whether demographic, clinical and conventional MRI markers at baseline were predictive for CI and longitudinal cognitive changes.

RESULTS

At baseline, 22% of patients had CI (impairment in ≥2 cognitive domains) with highest frequencies and severity in processing speed and executive functions. Demographics (fewer years of academic education, higher age, male sex), clinical (EDSS, depressive symptoms) but no conventional MRI characteristics were linked to baseline CI. At follow-up, only 14% of patients showed CI suggesting effects of retesting. Neither baseline characteristics nor initiation of treatment between baseline and follow-up was able to predict cognitive changes within the follow-up period of 1 year.

CONCLUSIONS

Identification of risk factors for short-term cognitive change in newly diagnosed MS or CIS is insufficient using only demographic, clinical and conventional MRI data. Change-sensitive, re-test reliable cognitive tests and more sophisticated predictors need to be employed in future clinical trials and cohort studies of early-stage MS to improve prediction.

Brain morphology, cognition, and β-amyloid in older adults with superior memory performance

The mechanisms underlying superior cognitive performance in some older adults are poorly understood. We used a multimodal approach to characterize imaging and cognitive features of 26 successful agers (SA; defined by superior episodic memory ability) and 103 typical older adults. Cortical thickness was greater in multiple regions in SA including right anterior cingulate and prefrontal cortex and was related to baseline memory performance. Similarly, hippocampal volume was greater in SA and associated with baseline memory. SA also had lower white matter hypointensity volumes and faster processing speed. While PiB burden did not differ, there was a significant group interaction in the relationship between age and PiB such that older SA individuals were less likely to have high brain β-amyloid. Over time, memory performance in typical older adults declined more rapidly than in SA, although there was limited evidence for different rates of brain atrophy. These findings indicate that superior memory in aging is related to greater cortical and white matter integrity as well as slower decline in memory performance.

Cognition During and After Multiple Sclerosis Relapse as Assessed With the Brief International Cognitive Assessment for Multiple Sclerosis

There is some evidence that cognition may be impaired during multiple sclerosis (MS) relapse. The aims of this study were to assess the cognitive status with the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in MS patients during relapse, in stable patients, and in healthy controls; to evaluate cognitive changes up to 3 months after relapse; and to estimate the impact of different factors on cognition after relapse. BICAMS was performed in 60 relapsing, 30 stable patients and 30 controls. Relapsing MS patients were assessed during relapse and one and three months after relapse. SDMT score was lower in relapsing than in stable patients. The mean scores of all BICAMS tests were higher one month after relapse than during relapse (p < 0.001). SDMT score after relapse improved in younger patients, who had more severe relapse (p < 0.05). BVMT-R score improved more in men, in patients with biologically active interferon-beta, in patients treated with methylprednisolone and in patients who were rehabilitated (p < 0.05). CVLT-II score improved in women and in patients with shorter relapse (p < 0.05). A neuropsychological assessment, like the evaluation of physical disability, is important during relapse. BICAMS may be suitable for a quick and effective assessment of cognition during relapse.

Gender Differences in Cognitive Test Performance in Adults With Heart Failure

BACKGROUND

Cognitive deficits are found in up to 73% of persons with heart failure (HF) and are associated with increased mortality and other poor clinical outcomes. It is known that women have better memory test performance than men do in healthy samples, but gender differences in cognitive performance in the context of HF are not well understood and may have important clinical implications.

OBJECTIVE

The objective of this study was to examine possible gender differences in cognitive function in a sample of individuals with HF (98.9% New York Heart Association class II and III).

METHODS

A total of 183 adults with HF (116 men and 67 women) completed a neuropsychological test battery as part of a larger project. Measures were chosen to assess functioning in attention/executive function and memory.

RESULTS

After controlling for demographic and medical factors, multivariate analysis of covariance revealed that men and women differed on memory test performance (λ = 0.90, F4, 169 = 4.76, P = .001). Post hoc comparisons revealed that women performed better on California Verbal Learning Test Learning, Short Recall, and Delayed Recall. No differences emerged on tests of attention/executive function (λ = 0.97, F5, 168 = 0.96, P = .44).

CONCLUSIONS

In this sample of persons with HF, men exhibited poorer performance on memory measures than women did. Future studies are needed to determine the underlying mechanisms for this pattern and its possible influence on daily function.

Sex differences evident in self-reported but not objective measures of driving

It has been consistently reported that women self-regulate their driving more than men. Volunteer drivers aged 75 years and older from the suburban outskirts of Sydney, Australia joined a longitudinal study in 2012-2014. GPS in-vehicle monitoring was used to objectively measure driving and surveys of driving patterns. The study included 343 drivers (203/343, 59% men) with an average age of 80 years. Our results revealed that men were 3.85 times more likely to report driving beyond their local shire during the past year (95% CI 2.03-5.72) and 1.81 times more likely to report that they do not avoid night driving (95% CI 1.21-3.22). In contrast sex was not predictive of any objective measure of driving during a one-week period of monitoring. These findings suggest that men and women report different self-regulation practices but that actual driving exposure is quite similar. These findings can inform strategies to promote safe mobility.

Gender differences in Parkinson's disease: A clinical perspective

Available data indicate that there are gender differences in many features of Parkinson's disease (PD). Precise identification of the gender differences is important to tailor treatment, predict outcomes, and meet other individual and social needs in women and men with PD. The aim of this study was to review the available clinical data on gender differences in PD. Original articles and meta-analyses published between 1990 and 2016 systematically exploring gender differences in PD were reviewed. There is slight male preponderance in incidence and prevalence of PD. PD starts earlier in men. Women tend to be more prone to develop tremor-dominant PD but are less rigid than men. Motor improvement after deep brain stimulation is equal in both sexes, but women tend to show better improvement in activities of daily living. Furthermore, women with PD show better results on tests for general cognitive abilities, outperform men in verbal cognitive tasks, show more pain symptoms, and score higher on depression scales. It seems, however, that the differences in cognition, mood, and pain perception are not disease specific as similar gender differences can be found in healthy subjects and in other neurological conditions. Despite PD being the most frequently studied movement disorder, studies investigating gender differences in PD are still scarce with most of the studies being cross-sectional. Good-quality, prospective, longitudinal studies analyzing gender differences in PD and comparing them to matched healthy controls are needed in order to properly address the issues of gender differences in PD.

Sex differences in verbal fluency: the role of strategies and instructions

Sex differences in verbal fluency performance and strategies are highly controversial, nevertheless suggesting a slight female advantage at least for phonemic fluency. A tendency of increased clustering of words into phonemic and semantic subcategories in men and increased switching between those categories in women has been suggested. In spatial tasks, it has been demonstrated that changes in instructions favoring a certain cognitive strategy can alter sex differences in performance. Such an approach has, however, not been attempted previously with verbal tasks. In the present investigation, 19 women in their luteal cycle phase and 23 men performed a phonemic and a semantic fluency task with three different instructions, one neutral, one emphasizing the clustering, and one emphasizing the switching of words. While under neutral instructions no sex differences were observed in verbal fluency performance and strategies, sex differences in switching and overall performance were observed in semantic fluency with an instruction requiring a switching strategy. Furthermore, correlation analyses suggested that the importance of strategies for overall performance differed between women and men. While only switching, but not clustering was related to overall verbal fluency performance in all tasks under all instructions, this relationship was driven by women in the phonemic task, but by men in the semantic task. These results highlight the importance of a consistent methodology in sex difference research. Slight variations in instructions may in part explain inconsistencies regarding sex differences in verbal fluency between previous studies.

Moderating effects of sex on the impact of diagnosis and amyloid positivity on verbal memory and hippocampal volume

Background

Alzheimer’s disease (AD) impacts men and women differently, but the effect of sex on predementia stages is unclear. The objective of this study was to examine whether sex moderates the impact of florbetapir positron emission tomography (PET) amyloid positivity (A⁺) on verbal learning and memory performance and hippocampal volume (HV) in normal cognition (NC) and early mild cognitive impairment (eMCI).

Methods

Seven hundred forty-two participants with NC and participants with eMCI from the Alzheimer’s Disease Neuroimaging Initiative (second cohort [ADNI2] and Grand Opportunity Cohort [ADNI-GO]) were included. All had baseline florbetapir PET measured, and 526 had screening visit HV measured. Regression moderation models were used to examine whether A⁺ effects on Rey Auditory Verbal Learning Test learning and delayed recall and right and left HV (adjusted for total intracranial volume) were moderated by diagnosis and sex. Age, cognition at screening, education, and apolipoprotein E ε4 carrier status were controlled.

Results

Women with A⁺, but not those with florbetapir PET amyloid negative (A-),eMCI showed poorer learning. For women with NC, there was no relationship of A⁺ with learning. In contrast, A⁺ men trended toward poorer learning regardless of diagnosis. A similar trend was found for verbal delayed recall: Women with A⁺, but not A-, eMCI trended toward reduced delayed recall; no effects were observed for women with NC or for men. Hippocampal analyses indicated that women with A⁺, but not those with A⁻, eMCI, trended toward smaller right HV; no significant A⁺ effects were observed for women with NC. Men showed similar, though nonsignificant, patterns of smaller right HV in A⁺ eMCI, but not in men with A⁻ eMCI or NC. No interactive effects of sex were noted for left HV.

Conclusions

Women with NC showed verbal learning and memory scores robust to A⁺, and women with A⁺ eMCI lost this advantage. In contrast, A⁺ impacted men’s scores less significantly or not at all, and comparably across those with NC and eMCI. Sex marginally moderated the relationship of A⁺ and diagnosis with right HV, such that women with NC showed no A⁺ effect and women with A⁺ eMCI lost that advantage in neural integrity; the pattern in men was less clear. These findings show that women with A⁺ eMCI (i.e., prodromal AD) have differential neural and cognitive decline, which has implications for considering sex in early detection of AD and development of therapeutics.

Sex differences in exercise efficacy to improve cognition: A systematic review and meta-analysis of randomized controlled trials in older humans

Exercise is a non-pharmacological strategy to mitigate the deleterious effects of aging on brain health. However, a large amount of variation exists in its efficacy. Sex of participants and exercise type are two possible factors contributing to this variation. To better understand this, we conducted a concurrent systematic review and meta-analysis of cognitively healthy older adults. Executive functions, episodic memory, visuospatial function, word fluency, processing speed and global cognitive function were examined for exercise- and sex-dependent effects. For executive functions, three types of exercise interventions - aerobic training, resistance training, and multimodal training (i.e., both aerobic and resistance training) - were associated with larger effect sizes in studies comprised of a higher percentage of women compared to studies with a lower percentage of women. This suggests that women's executive processes may benefit more from exercise than men. Regardless of sex, compared to control, all three exercise training approaches enhanced visuospatial function, but only multimodal training enhanced episodic memory. Overall, aerobic training led to greater benefits than resistance training in global cognitive function and executive functions, while multimodal combined training led to greater benefits than aerobic training for global cognitive function, episodic memory, and word fluency. Possible underlying mechanisms, including brain-derived neurotrophic factor and sex steroid hormones, are discussed.

Gender differences of neuropsychological profiles in cognitively normal older people without amyloid pathology

OBJECTIVE

To investigate the impact of sex on cognition among cognitively normal older people without amyloid pathology.

METHODS

The study sample consisted of 83 males (mean age 74years, ranging from 65 to 88years) and 111 females (mean age 72years, ranging from 65 to 89years) who were cognitively normal without amyloid pathology confirmed by Pittsburgh compound B PET scan. We examined the sex discrepancies in cognition using a comprehensive neuropsychological battery.

RESULTS

Our data showed significantly greater advantage for women than men on the tasks of verbal memory and category fluency while better performance of naming in men than women when age, education and depressive symptoms were considered.

CONCLUSION

These findings highlight the importance of considering sex differences in the interpretation of cognitive data which contribute to clinical diagnosis of neurodegenerative disorders, such as Alzheimer's disease.

Sex Differences and Menstrual Cycle Dependent Changes in Cognitive Strategies during Spatial Navigation and Verbal Fluency

Men typically outperform women in spatial navigation tasks, while the advantage of women in verbal fluency is more controversial. Sex differences in cognitive abilities have been related to sex-specific cognitive strategies on the one hand and sex hormone influences on the other hand. However, sex hormone and menstrual cycle influences on cognitive strategies have not been previously investigated. In the present study we assessed cognitive strategy use during spatial navigation and verbal fluency in 51 men and 49 women. In order to evaluate sex hormone influences, all participants completed two test sessions, which were time-locked to the early follicular (low estradiol and progesterone) and mid-luteal cycle phase (high estradiol and progesterone) in women. As hypothesized, men outperformed women in navigation, whereas women outperformed men in phonemic verbal fluency. Furthermore, women switched more often between categories in the phonemic fluency condition, compared to men, indicating sex-specific strategy use. Sex differences in strategy use during navigation did, however, not follow the expected pattern. Menstrual cycle phase, however, did modulate strategy use during navigation as expected, with improved performance with the landmark strategy in the luteal, compared to the follicular phase. No menstrual cycle effects were observed on clustering or switching during verbal fluency. This suggests a modulation of cognitive strategy use during spatial navigation, but not during verbal fluency, by relative hormone increases during the luteal phase of the menstrual cycle.

Stress and gender effects on prefrontal cortex oxygenation levels assessed during single and dual-task walking conditions

The ability to walk is critical for functional independence and wellbeing. The pre-frontal cortex (PFC) plays a key role in cognitive control of locomotion, notably under attention-demanding conditions. Factors that influence brain responses to cognitive demands of locomotion, however, are poorly understood. Herein, we evaluated the individual and combined effects of gender and perceived stress on stride velocity and PFC Oxygenated Hemoglobin (HbO₂ ) assessed during single and dual-task walking conditions. The experimental paradigm included Normal Walk (NW); Cognitive Interference (Alpha); and Walk-While-Talk (WWT) tasks. An instrumented walkway was used to assess stride velocity in NW and WWT conditions. Functional Near-Infrared-Spectroscopy (fNIRS) was used to quantify PFC HbO₂ levels during NW, Alpha and WWT. Perceived task-related stress was evaluated with a single 11-point scale item. Participants were community residing older adults (age = 76.8 ± 6.7 years; %female = 56). Results revealed that higher perceived stress was associated with greater decline in stride velocity from single to dual-task conditions among men. Three-way interactions revealed that gender moderated the effect of perceived stress on changes in HbO₂ levels comparing WWT to NW and Alpha. Attenuation in the increase in HbO₂ levels, in high compared to low perceived stress levels, from the two single task conditions to WWT was observed only in men. Thus, older men may be more vulnerable to the effect of perceived stress on the change in PFC oxygenation levels across walking conditions that vary in terms of cognitive demands. These findings confer important implications for assessment and treatment of individuals at risk of mobility impairments.

Prefrontal activity decline in women under a single dose of diazepam during rule-guided responses: an fMRI study

Daily life events confront us with new situations demanding responses to usual and unusual rules. Diazepam (DZ), a clinically important drug, facilitates the inhibitory activity of the GABAergic system. Prefrontal cortex, rich in DZ receptors, coordinates necessary resources to direct actions according to rules. The balance between excitatory and inhibitory activity is critical to achieve optimal function of brain systems leading to complex functions. Major sex differences in the physiological mechanisms of the GABAergic system have been reported. However, the differential influence of DZ on men and women in neural activity during behavior directed by frontal lobes remains unexplored. The ability of healthy volunteers to select responses following usual/congruent and novel/incongruent rules, and brain correlates were measured with fMRI under the administration of DZ and a placebo. 10 mg of DZ was enough to decrease the performance in a different manner between men and women. While reaction times increased in both men and women, women committed more errors selecting responses than men under DZ. Men demonstrated increased activity, while women demonstrated decreased activity in frontal regions involved in response selection of rules. These findings could have important consequences in understanding the differential influences of DZ between the sexes in complex daily life situations. More importantly, this study emphasizes the importance of understanding the differential effects on men and women of drugs widely employed by society, thereby achieves better therapeutic results and avoids side effects that the present study revealed to be different between sexes.

Verbal memory declines more in female patients with Parkinson's disease: the importance of gender-corrected normative data

BACKGROUND

Data on gender-specific profiles of cognitive functions in patients with Parkinson's disease (PD) are rare and inconsistent, and possible disease-confounding factors have been insufficiently considered.

METHOD

The LANDSCAPE study on cognition in PD enrolled 656 PD patients (267 without cognitive impairment, 66% male; 292 with mild cognitive impairment, 69% male; 97 with PD dementia, 69% male). Raw values and age-, education-, and gender-corrected Z scores of a neuropsychological test battery (CERAD-Plus) were compared between genders. Motor symptoms, disease duration, l-dopa equivalent daily dose, depression - and additionally age and education for the raw value analysis - were taken as covariates.

RESULTS

Raw-score analysis replicated results of previous studies in that female PD patients were superior in verbal memory (word list learning, p = 0.02; recall, p = 0.03), while men outperformed women in visuoconstruction (p = 0.002) and figural memory (p = 0.005). In contrast, gender-corrected Z scores showed that men were superior in verbal memory (word list learning, p = 0.02; recall, p = 0.02; recognition, p = 0.04), while no difference was found for visuospatial tests. This picture could be observed both in the overall analysis of PD patients as well as in a differentiated group analysis.

CONCLUSIONS

Normative data corrected for gender and other sociodemographic variables are relevant, since they may elucidate a markedly different cognitive profile compared to raw scores. Our study also suggests that verbal memory decline is stronger in women than in men with PD. Future studies are needed to replicate these findings, examine the progression of gender-specific cognitive decline in PD and define different underlying mechanisms of this dysfunction.

Sex on the brain! Associations between sexual activity and cognitive function in older age

BACKGROUND

the relationship between cognition and sexual activity in healthy older adults is under-researched. A limited amount of research in this area has shown that sexual activity is associated with better cognition in older men. The current study explores the possible mediating factors in this association in men and women, and attempts to provide an explanation in terms of physiological influences on cognitive function.

METHODS

using newly available data from Wave 6 of the English Longitudinal Study of Ageing, the current study explored associations between sexual activity and cognition in adults aged 50-89 (n = 6,833). Two different tests of cognitive function were analysed: number sequencing, which broadly relates to executive function, and word recall, which broadly relates to memory.

RESULTS

after adjusting for age, education, wealth, physical activity, depression, cohabiting, self-rated health, loneliness and quality of life, there were significant associations between sexual activity and number sequencing and recall in men. However, in women there was a significant association between sexual activity and recall, but not number sequencing.

CONCLUSIONS

possible mediators of these associations (e.g. neurotransmitters) are discussed. The cross-sectional nature of the analysis is limiting, but provides a promising avenue for future explorations and longitudinal studies. The findings have implications for the promotion of sexual counselling in healthcare settings, where maintaining a healthy sex life in older age could be instrumental in improving cognitive function and well-being.

Sex differences in cognitive trajectories in clinically normal older adults

Age effects on cognitive functioning are well-documented, but effects of sex on trajectories of cognitive aging are less clear. We examined cognitive ability across a variety of measures for 1,065 to 2,127 participants (mean baseline age 64.1 to 69.7 years) from the Baltimore Longitudinal Study of Aging who were repeatedly tested over a mean follow-up interval of 3.0 to 9.0 years with a mean of 2.3 to 4.4 assessments. Memory and other cognitive tests were administered at each visit, assessing mental status, verbal learning and memory, figural memory, language, attention, perceptuomotor speed and integration, executive function, and visuospatial ability. Importantly, participants free from cognitive impairment at all time points were used in the analyses. Results showed that for all tests, higher age at baseline was significantly associated with lower scores, and performance declined over time. In addition, advancing age was associated with accelerated longitudinal declines in performance (trend for mental status). After adjusting for age, education, and race, sex differences were observed across most tests of specific cognitive abilities examined. At baseline, males outperformed females on the 2 tasks of visuospatial ability, and females outperformed males in most other tests of cognition. Sex differences in cognitive change over time indicated steeper rates of decline for men on measures of mental status, perceptuomotor speed and integration, and visuospatial ability, but no measures on which women showed significantly steeper declines. Our results highlight greater resilience to age-related cognitive decline in older women compared with men.

Executive Dyscontrol of Learning and Memory: Findings from a Clade C HIV-positive South African Sample

OBJECTIVE

Although pre-clinical work suggests there might be differences in neurovirulence across HIV-1 clades, few studies investigate neuropsychological deficits in the globally predominant clade C infection. The purpose of this study was to investigate verbal learning and memory performance in HIV-positive individuals in Cape Town, South Africa, where clade C is the most prevalent subtype of the virus.

METHOD

Using a case-control design, we recruited 53 isiXhosa-speaking, cART-naïve HIV-positive adults and 53 demographically matched HIV-negative controls. Participants were administered a comprehensive neuropsychological test battery. The test of interest was the Hopkins Verbal Learning Test-Revised (HVLT-R); previous studies have used that instrument to identify executive dyscontrol of verbal learning and memory processes in clade B HIV-positive participants.

RESULTS

HIV-positive participants showed only partial impairment on the HVLT-R's learning/memory components (e.g., they recalled significantly fewer words across learning trials, but displayed relatively intact performance on delayed recall trials). They also displayed little executive dyscontrol over encoding and retrieval processes (e.g., there were no significant between-group differences on measures of semantic or serial clustering).

CONCLUSIONS

Post-cART era studies suggest that verbal learning and memory performance is impaired in clade B samples, at least partially due to executive dyscontrol over encoding and retrieval processes. We found few such impairments in the current clade C sample. These preliminary findings suggest different CNS vulnerability across clades that would have implications for delineating clade-specific neuropathological and neurocognitive clinical features.

Insulin resistance is associated with poorer verbal fluency performance in women

AIMS/HYPOTHESIS

Type 2 diabetes is an independent risk factor for cognitive decline. Insulin resistance occurring during midlife may increase the risk of cognitive decline later in life. We hypothesised that insulin resistance is associated with poorer cognitive performance and that sex and APOE*E4 might modulate this association.

METHODS

The association of insulin resistance and APOE*E4 genotype on cognitive function was evaluated in a nationwide Finnish population-based study (n = 5,935, mean age 52.5 years, range 30-97 years). HOMA-IR was used to measure insulin resistance. Cognitive function was tested by word-list learning, word-list delayed-recall, categorical verbal fluency and simple and visual-choice reaction-time tests. Linear regression analysis was used to determine the association between HOMA-IR and the results of the cognitive tests.

RESULTS

Higher HOMA-IR was associated with poorer verbal fluency in women (p < 0.0001) but not in men (p = 0.56). Higher HOMA-IR was also associated with poorer verbal fluency in APOE*E4 -negative individuals (p = 0.0003), but not in APOE*E4 carriers (p = 0.28). Furthermore, higher HOMA-IR was associated with a slower simple reaction time in the whole study group (p = 0.02).

CONCLUSIONS/INTERPRETATION

To our knowledge, this is the first comprehensive, population-based study, including both young and middle-aged adults, to report that female sex impacts the association of HOMA-IR with verbal fluency. Our study was cross-sectional, so causal effects of HOMA-IR on cognition could not be evaluated. However, our results suggest that HOMA-IR could be an early marker for an increased risk of cognitive decline in women.

Sex Differences in Clinical Features of Early, Treated Parkinson's Disease

Introduction

To improve our understanding of sex differences in the clinical characteristics of Parkinson’s Disease, we sought to examine differences in the clinical features and disease severity of men and women with early treated Parkinson’s Disease (PD) enrolled in a large-scale clinical trial.

Methods

Analysis was performed of baseline data from the National Institutes of Health Exploratory Trials in Parkinson’s Disease (NET-PD) Long-term Study-1, a randomized, multi-center, double-blind, placebo-controlled study of 10 grams of oral creatine/day in individuals with early, treated PD. We compared mean age at symptom onset, age at PD diagnosis, and age at randomization between men and women using t-test statistics. Sex differences in clinical features were evaluated, including: symptoms at diagnosis (motor) and symptoms at randomization (motor, non-motor, and daily functioning).

Results

1,741 participants were enrolled (62.5% male). No differences were detected in mean age at PD onset, age at PD diagnosis, age at randomization, motor symptoms, or daily functioning between men and women. Differences in non-motor symptoms were observed, with women demonstrating better performance compared to men on SCOPA-COG (Z = 5.064, p<0.0001) and Symbol Digit Modality measures (Z = 5.221, p<0.0001).

Conclusions

Overall, men and women did not demonstrate differences in clinical motor features early in the course of PD. However, the differences observed in non-motor cognitive symptoms suggests further assessment of the influence of sex on non-motor symptoms in later stages of PD is warranted.

Executive functions in men and postmenopausal women

INTRODUCTION

This study was designed to assess sex differences in older adults (55-65 years old) in executive functions and to examine the influence of hormone therapy (HT) in postmenopausal women.

METHOD

We have assessed task performance in memory, visuospatial, and executive functions in 29 women using HT, 29 women who never used HT, and 30 men.

RESULTS

Men outperformed never users in task switching and updating. HT users outperformed never users in updating. HT users outperformed never users and men in visual divided attention.

DISCUSSION

The present study support previous findings that sex and HT impact cognition and bring new insights on sex and HT-related differences in executive functions.

Men and women with fibromyalgia: Relation between attentional function and clinical symptoms

OBJECTIVES

This study was the first to explore whether individuals with fibromyalgia (FM) have different cognitive alterations (i.e., in alertness, orienting, and executive control) depending on their sex. We also analysed possible gender differences in the relationships between cognitive functioning and some of the main symptoms of FM.

DESIGN

Cross-sectional study.

METHODS

Two clinical groups with FM (n = 58 women and n = 20 men) and two healthy control groups (n = 21 women and n = 27 men) aged between 30 and 60 years old participated in this study. Pain intensity, sleep disturbance, depression, anxiety, pain catastrophizing, and daily functioning were evaluated with self-report measures. Attentional function was assessed with the ANT-I task (Attentional Network Test-Interactions).

RESULTS

Mixed ANOVAs showed impairment in vigilance and executive control in both male and female patients with FM compared with controls. Control men were faster than control women, but FM eliminated sex differences. In addition, attention deficit was associated with worse daily functioning in women but not in men with FM. Emotional distress and sleep disruption seemed to contribute differently to these cognitive alterations in both sexes.

CONCLUSIONS

Therapy strategies aimed at reducing emotional distress and sleep disruption are likely to improve cognitive function by enhancing vigilance. Therapies aimed at reducing emotional distress seem to improve attentional function more in women than in men; those aimed at improving sleep quality are likely to reduce a vigilance/alertness deficit in women and executive problems in men.

Sex-specific strategy use and global-local processing: a perspective toward integrating sex differences in cognition

This article reviews the literature on sex-specific strategy use in cognitive tasks with the aim to carve out a link between sex differences in different cognitive tasks. I conclude that male strategies are commonly holistic and oriented toward global stimulus aspects, while female strategies are commonly decomposed and oriented toward local stimulus aspects. Thus, the strategies observed in different tasks, may depend on sex differences in attentional focus and hence sex differences in global-local processing. I hypothesize that strategy use may be sex hormone dependent and hence subject to change over the menstrual cycle as evidenced by findings in global-local processing and emotional memory. Furthermore, I propose sex hormonal modulation of hemispheric asymmetries as one possible neural substrate for this theory, thereby building on older theories, emphasizing the importance of sex differences in brain lateralization. The ideas described in the current article represent a perspective toward a unifying approach to the study of sex differences in cognition and their neural correlates.

Age-related differences in multiple task monitoring

Coordinating multiple tasks with narrow deadlines is particularly challenging for older adults because of age related decline in cognitive control functions. We tested the hypothesis that multiple task performance reflects age- and gender-related differences in executive functioning and spatial ability. Young and older adults completed a multitasking session with four monitoring tasks as well as separate tasks measuring executive functioning and spatial ability. For both age groups, men exceeded women in multitasking, measured as monitoring accuracy. Individual differences in executive functioning and spatial ability were independent predictors of young adults' monitoring accuracy, but only spatial ability was related to sex differences. For older adults, age and executive functioning, but not spatial ability, predicted multitasking performance. These results suggest that executive functions contribute to multiple task performance across the adult life span and that reliance on spatial skills for coordinating deadlines is modulated by age.

Why women see differently from the way men see? A review of sex differences in cognition and sports

The differences of learning and memory between males and females have been well documented and confirmed by both human and animal studies. The sex differences in cognition started from early stage of neuronal development and last through entire life span. The major biological basis of the gender-dependent cognitive activity includes two major components: sex hormone and sex-related characteristics, such as sex-determining region of the Y chromosome (SRY) protein. However, the knowledge of how much biology of sex contributes to normal cognitive function and elite athletes in various sports are still pretty limited. In this review, we will be focusing on sex differences in spatial learning and memory - especially the role of male- and female-type cognitive behaviors in sports.

Sex differences in cognitive impairment and Alzheimer's disease

Studies have shown differences in specific cognitive ability domains and risk of Alzheimer's disease between the men and women at later age. However it is important to know that sex differences in cognitive function during adulthood may have their basis in both organizational effects, i.e., occurring as early as during the neuronal development period, as well as in activational effects, where the influence of the sex steroids influence brain function in adulthood. Further, the rate of cognitive decline with aging is also different between the sexes. Understanding the biology of sex differences in cognitive function will not only provide insight into Alzheimer's disease prevention, but also is integral to the development of personalized, gender-specific medicine. This review draws on epidemiological, translational, clinical, and basic science studies to assess the impact of sex differences in cognitive function from young to old, and examines the effects of sex hormone treatments on Alzheimer's disease in men and women.

Gender differences in awareness and outcomes during acute traumatic brain injury recovery

BACKGROUND

Recent literature on traumatic brain injury (TBI), though mixed when reporting outcomes, seems collectively to suggest possible gender advantage for women in postinjury recovery, especially in executive functions. Hormonal neuroprotection, through female reproductive hormones, is often proposed as an underlying factor in these results. We explored potential gender differences in an aspect of executive functions, self-awareness (SA), which is often impaired after TBI, limits patient effort in critical rehabilitation, and increases caregiver burden.

METHODS

Within a prospective survey, repeated-measures design, 121 patients with moderate or severe TBI undergoing acute rehabilitation in a Level 1 trauma center, a family member or caregiver informant, and a treating clinician were asked to complete the Patient Competency Rating Scale (PCRS) and the Frontal Systems Behavior Scale (FrSBe) at admission and discharge.

RESULTS

Although overall, women and men with TBI showed generally similar levels of SA, women had significantly better awareness of their injury-related deficits at acute rehabilitation discharge, even when controlling for age, education, and injury severity.

CONCLUSIONS

Mixed findings in this study mirror the pattern of results that dominate the published literature on gender and TBI. Gender differences in executive dysfunction may not be as large or robust as some researchers argue. In addition, complex interplays of socialization, gender-role expectations, naturally occurring male and female ability differences, and differences in access to postinjury rehabilitation are understudied potential moderators.

Further characterization of quinpirole-elicited yawning as a model of dopamine D3 receptor activation in male and female monkeys

The dopamine (DA) D3 receptor (D3R) has been associated with impulsivity, pathologic gambling, and drug addiction, making it a potential target for pharmacotherapy development. Positron emission tomography studies using the D3R-preferring radioligand [(11)C]PHNO ([(11)C](+)-propyl-hexahydro-naphtho-oxazin) have shown higher binding potentials in drug abusers compared with control subjects. Preclinical studies have examined D3R receptor activation using the DA agonist quinpirole and the unconditioned behavior of yawning. However, the relationship between quinpirole-elicited yawning and D3R receptor availability has not been determined. In Experiment 1, eight drug-naive male rhesus monkeys were scanned with [(11)C]PHNO, and the ability of quinpirole (0.01-0.3 mg/kg i.m.) to elicit yawning was examined. Significant positive (globus pallidus) and negative (caudate nucleus, putamen, ventral pallidum, and hippocampus) relationships between D3R receptor availability and quinpirole-induced yawns were noted. Experiment 2 replicated earlier findings that a history of cocaine self-administration (n = 11) did not affect quinpirole-induced yawning and extended this to examine monkeys (n = 3) with a history of methamphetamine (MA) self-administration and found that monkeys with experience self-administering MA showed greater potency and significantly higher quinpirole-elicited yawning compared with controls. Finally, quinpirole-elicited yawning was studied in drug-naive female monkeys (n = 6) and compared with drug-naive male monkeys (n = 8). Sex differences were noted, with quinpirole being more potent and eliciting significantly more yawns in males compared with females. Taken together these findings support the use of quinpirole-elicited yawning as a behavioral tool for examining D3R activation in monkeys and that both drug history and sex may influence individual sensitivity to the behavioral effects of D3R compounds.

Influence of gender and age on cognitive inhibition in late-onset depression: a case-control study

OBJECTIVE

To compare cognitive inhibition performance between people with early-onset (EOD) or late-onset depression (LOD) and controls, and between women and men with LOD.

METHODS

On the basis of a case-control design, global executive performance (Frontal Assessment Battery); verbal (Hayling), attention (Stroop), and motor (Go/No-Go) components of cognitive inhibition; mental shifting (Trail Making Test parts A and B); and updating in working memory (Wechsler Adult Intelligence Scale) were assessed in 40 participants (10 depressed women with LOD (i.e., ≥60 years old), 10 depressed women with EOD (i.e., <60 years old), 10 healthy women and 10 depressed men with LOD (i.e., ≥60 years old)).

RESULTS

Older depressed women, irrespective of age of depression onset, had greater cognitive inhibition impairments (attention and verbal component) compared with healthy women. LOD was significantly associated with the attention component of cognitive inhibition impairment, unlike EOD (p = 0.026). No executive differences were found regarding age of first-onset depression in older depressed women, and between women and men with LOD.

CONCLUSION

Cognitive inhibition impairment, and more specifically its attention component, was the main characteristic of depression in the studied sample of older adults, independently of gender and age of depression onset. It is essential to perform similar studies in both genders in view of future tailor-made therapeutic modalities.