The importance of sleep in memory, learning, and other cognitive functions.

Sleep is important for brain health, having both a restorative function and playing an important role in cognitive functions, e.g., attention, memory, learning, and planning. This review finds that sleep disturbances are prevalent and associated with poorer cognitive functioning in neurodegenerative disorders such as Parkinson's disease and in people with non-neurodegenerative diseases such as cancer and mood disorders. Screening for and treating sleep disturbances are potential supplementary approaches to preventing and treating cognitive impairment.

Cancer-related cognitive impairment in non-CNS cancer patients: Targeted review and future action plans in Europe.

Cancer-related cognitive impairment (CRCI) has increasingly been identified over the last two decades in non-CNS system cancer patients. Across Europe, researchers have contributed to this effort by developing preclinical models, exploring underlying mechanisms and assessing cognitive and quality of life changes. The ultimate goal is to develop interventions to treat patients experiencing CRCI. To do so, new challenges need to be addressed requiring the implementation of multidisciplinary research groups. In this consensus paper, we summarize the state of the art in the field of CRCI combined with the future challenges and action plans in Europe. These challenges include data sharing/pooling, standardization of assessments as well as assessing additional biomarkers and neuroimaging investigations, notably through translational studies. We conclude this position paper with specific actions for Europe based on shared scientific expert opinion and stakeholders involved in the Innovative Partnership for Action Against Cancer, with a particular focus on cognitive intervention programs.

Changes in sleep following internet-delivered cognitive-behavioral therapy for insomnia in women treated for breast cancer: A 3-year follow-up assessment.

BACKGROUND: Sleep disturbances are common in women treated for breast cancer. We have previously shown that internet-delivered cognitive-behavioral therapy for insomnia (e-CBT-I) is an efficacious, low-cost treatment approach. Furthermore, research has shown that e-CBT-I can result in sustained improvements at 12 months post-treatment. However, given the complexity and long duration of post-treatment symptomatology in breast cancer patients, as well as the recommended use of antihormonal therapy for up to 10 years, it is relevant to investigate long-term (>12 months) changes in sleep following e-CBT-I in this population. In the present study, we report data from a 3-year long-term follow-up assessment after e-CBT-I. METHODS: Women treated for breast cancer with sleep disturbances (Pittsburg Sleep Quality Index [PSQI] global score >5) who had previously been enrolled in a randomized-controlled trial investigating the efficacy of e-CBT-I (n = 255), were invited to participate in a 3-year follow-up study. All women in the initial control group had also been granted access to e-CBT-I. Assessment included self-reported sleep quality (PSQI), insomnia severity (Insomnia Severity Index, ISI), cancer-related fatigue and symptoms of depression. Within-group changes in these outcomes from baseline to the 3-year long-term follow-up assessment were analyzed. RESULTS: A total of 131 women (51%) participated in the 3-year follow-up study of which 77 (59%) were from the initial intervention group and 54 (41%) from the initial control group. For the pooled sample, within-group improvements from baseline to the 3-year follow-up assessment corresponding to large effect sizes were observed in sleep quality (Cohen's d = 1.0 95% CI [0.78, 1.21]) and insomnia severity (Cohen's d = 1.36 CI 95% [1.12, 1.59]). Similar changes were observed in cancer-related fatigue (Cohen's d = 0.48 CI 95% [0.30, 0.66]) and symptoms of depression (Cohen's d = 0.80 CI 95%. [0.60, 0.99]). The proportion of patients with scores above established cut-offs on the PSQI and the ISI were 56.1% and 29.8%, respectively. Within the initial intervention group, 15.6% evidenced relapse at the 3-year assessment. CONCLUSION: Overall, these results indicate that long-term sleep quality and insomnia severity following the use of e-CBT-in women treated for breast cancer is significantly lower than the pre-treatment levels. However, a substantial proportion of participants still evidence sleep disturbances.

Cognitive impairment and associations with structural brain networks, endocrine status, and risk genotypes in newly orchiectomized testicular cancer patients.

A higher incidence of cognitive impairment (CI) has previously been reported among orchiectomized testicular cancer patients (TCPs), but little is known about the underlying pathophysiology. The present study assessed CI in newly orchiectomized TCPs and explored the structural brain networks, endocrine status, and selected genotypes. Forty TCPs and 22 healthy controls (HCs) underwent neuropsychological testing and magnetic resonance imaging, and provided a blood sample. CI was defined as a z-score ≤ -2 on one neuropsychological test or ≤ -1.5 on two neuropsychological tests, and structural brain networks were investigated using graph theory. Associations of cognitive performance with brain networks, endocrine status (including testosterone levels and androgen receptor CAG repeat length), and genotypes (APOE, BDNF, COMT) were explored. Compared with HCs, TCPs performed poorer on 6 out of 15 neuropsychological tests, of which three tests remained statistically significant when adjusted for relevant between-group differences (p < 0.05). TCPs also demonstrated more CI than HCs (65% vs. 36%; p = 0.04). While global brain network analysis revealed no between-group differences, regional analysis indicated differences in node degree and betweenness centrality in several regions (p < 0.05), which was inconsistently associated with cognitive performance. In TCPs, CAG repeat length was positively correlated with delayed memory performance (r = 0.36; p = 0.02). A COMT group × genotype interaction effect was found for overall cognitive performance in TCPs, with risk carriers performing worse (p = 0.01). No effects were found for APOE, BDNF, or testosterone levels. In conclusion, our results support previous findings of a high incidence of CI in newly orchiectomized TCPs and provide novel insights into possible mechanisms.

Androgen deprivation therapy and cognitive decline-associations with brain connectomes, endocrine status, and risk genotypes.

BACKGROUND: Evidence suggests that prostate cancer (PC) patients undergoing androgen deprivation therapy (ADT) are at risk for cognitive decline (CD), but the underlying mechanisms are less clear. In the present study, changes in cognitive performance and structural brain connectomes in PC patients undergoing ADT were assessed, and associations of cognitive changes with endocrine status and risk genotypes were explored. METHODS: Thirty-seven PC patients underwent cognitive assessment, structural MRI, and provided blood samples prior to ADT and after 6 months of treatment. Twenty-seven age- and education-matched healthy controls (HCs) underwent the same assessments. CD was determined using a standardized regression-based approach and defined as z-scores ≤ -1.64. Changes in brain connectomes were evaluated using graph theory. Associations of CD with testosterone levels and genotypes (APOE, COMT, BDNF) were explored. RESULTS: Compared with HCs, PC patients demonstrated reduced testosterone levels (p < 0.01) and higher rates of decline for 13 out of 15 cognitive outcomes, with three outcomes related to two cognitive domains, i.e., verbal memory and visuospatial learning and memory, reaching statistical significance (p ≤ 0.01-0.04). Testosterone level changes did not predict CD. COMT Met homozygote PC patients evidenced larger reductions in visuospatial memory compared with Val carriers (p = 0.02). No between-group differences were observed in brain connectomes across time, and no effects were found of APOE and BDNF. CONCLUSIONS: Our results indicate that PC patients undergoing ADT may evidence CD, and that COMT Met homozygotes may be at increased risk of CD. The results did not reveal changes in brain connectomes or testosterone levels as underlying mechanisms. More research evaluating the role of ADT-related disruption of the dynamics of the hypothalamic-pituitary-gonadal axis is needed.

Cognitive changes and brain connectomes, endocrine status, and risk genotypes in testicular cancer patients-A prospective controlled study.

OBJECTIVE: Previous research has indicated cognitive decline (CD) among testicular cancer patients (TCPs), even in the absence of chemotherapy, but little is known about the underlying pathophysiology. The present study assessed changes in cognitive functions and structural brain connectomes in TCPs and explored the associations between cognitive changes and endocrine status and hypothesized risk genotypes. METHODS: Thirty-eight newly orchiectomized TCPs and 21 healthy controls (HCs) comparable to TCPs in terms of age and years of education underwent neuropsychological testing, structural MRI, and a biological assessment at baseline and 6 months later. Cognitive change was assessed with a neuropsychological test battery and determined using a standardized regression-based approach, with substantial change defined as z-scores ≤-1.64 or ≥1.64. MRI scans and graph theory were used to evaluate changes in structural brain connectomes. The associations of cognitive changes with testosterone levels, androgen receptor gene (AR) CAG repeat length, and genotypes (APOE, COMT, and BDNF) were explored. RESULTS: Compared with HCs, TCPs showed higher rates of substantial decline on processing speed and visuospatial ability and higher rates of substantial improvement on verbal recall and visuospatial learning (p < 0.05; OR = 8.15-15.84). Brain network analysis indicated bilateral thalamic changes in node degree in HCs, but not in TCPs (p < 0.01). In TCPs, higher baseline testosterone levels predicted decline in verbal memory (p < 0.05). No effects were found for AR CAG repeat length, APOE, COMT, or BDNF. CONCLUSIONS: The present study confirms previous findings of domain-specific CD in TCPs following orchiectomy, but also points to domain-specific improvements. The results do not indicate changes in brain connectomes or endocrine status to be the main drivers of CD. Further studies evaluating the mechanisms underlying CD in TCPs, including the possible role of the dynamics of the hypothalamic-pituitary-gonadal axis, are warranted.

Testosterone Supplementation and Cognitive Functioning in Men-A Systematic Review and Meta-Analysis.

Testosterone supplementation (TS) is assumed important for cognitive functioning in men, but conflicting results have prevented firm conclusions. The current study systematically reviewed available randomized controlled trials (RCTs) on effects of TS on cognitive functioning in men, subjected the findings to meta-analysis, and explored between-study differences as possible moderators of the effects. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, two authors independently searched for eligible records in the electronic databases of PubMed, PsycINFO, Web of Science, the Cochrane Library, Cumulative Index of Nursing and Allied Health, and Embase and determined eligibility using the following (population, intervention, comparison, outcome) criteria: population, male adults (>18 years); intervention, TS; comparison, placebo; and outcome, results of standardized neuropsychological tests. Following duplicate removal, 3873 records were screened with 92 remaining for full-text screening. Twenty-one papers reporting results of 23 independent RCTs were included, of which none treated samples of clinically hypogonadal men. The small improvement found in overall cognitive functioning (Hedges g = 0.09; CI 95%: -0.02 to 0.19) failed to reach statistical significance (P = 0.108) and approached zero when adjusting for possible publication bias (g = 0.04). The effects for the 11 individual cognitive domains did not reach statistical significance (g: -0.04 to 0.19, P: 0.061 to 0.989). Small statistically significant (P < 0.05) effects were found for five study subsets but failed to meet the fail-safe criterion. The available evidence indicates that effects of TS on cognitive functioning in men with testosterone levels within normal ranges are less robust and of insufficient magnitude to be of clinical relevance. The effects in clinically hypogonadal men remain to be investigated.