A pilot study of prospective memory functioning in early breast cancer survivors

Investigating executive functioning and episodic future thinking in Iranian women with breast cancer

BACKGROUND

This study examined executive functioning and episodic future thinking among Iranian women with breast cancer.

METHOD

We recruited 40 healthy female community volunteers and 80 females with breast cancer (either currently undergoing chemotherapy n = 40 or not undergoing chemotherapy n = 40). Participants were assessed using cognitive tasks that assessed executive functioning and episodic future thinking and a measure of cancer-related fatigue.

RESULTS

Both cancer groups had poorer performance than controls on all measures of executive functioning and episodic future thinking. Those undergoing chemotherapy had poorer performance on all measures of executive functioning than those not undergoing chemotherapy. Cross-sectional mediation analyses revealed cancer-related fatigue had a significant mediator role between cancer group and executive functioning and episodic future thinking.

CONCLUSION

Those with breast cancer, particularly those undergoing chemotherapy, may be experiencing cognitive difficulties. These cognitive concerns should be considered by health teams as addressing these impairments may assist in improving quality of life and treatment adherence.

Memory Impairments and Wellbeing in Breast Cancer Patients: A Systematic Review

Breast cancer is one of the most diagnosed cancers among women. Its effects on the cognitive and wellbeing domains have been widely reported in the literature, although with inconsistent results. The central goal of this review was to identify, in women with breast cancer, the main memory impairments, as measured by objective and subjective tools and their relationship with wellbeing outcomes. The systematic literature search was conducted in the PubMed, Scopus, and ProQuest databases. The selected studies included 9 longitudinal and 10 cross-sectional studies. Although some studies included participants undergoing multimodal cancer therapies, most focused on chemotherapy's effects (57.89%; n = 11). The pattern of results was mixed. However, studies suggested more consistently working memory deficits in breast cancer patients undergoing chemotherapy. In addition, some associations have been identified between objective memory outcomes (verbal memory) and wellbeing indicators, particularly depression and anxiety. The inconsistencies in the results could be justified by the heterogeneity of the research designs, objective and subjective measures, and sample characteristics. This review confirms that more empirical evidence is needed to understand memory impairments in women with breast cancer. An effort to increase the homogeneity of study methods should be made in future studies.

Sleep-dependent memory consolidation in breast cancer: Use of a virtual reality prospective memory task

Background

Previous studies have revealed both sleep alterations and prospective memory (PM) impairments in breast cancer (BC) patients. PM refers to memory of intended actions and is crucial for daily living tasks and treatment compliance. As sleep is known to favor memory consolidation, one may expect that changes in sleep quality related to BC would have an impact on PM performance. This study aimed at assessing sleep-dependent consolidation of intentions using an ecological, virtual reality-based PM task in BC patients not treated with chemotherapy.

Materials and methods

Thirty-seven early stages BC patients and 21 healthy controls (HC) participated in this study. PM was assessed using a virtual reality task, during which participants learnt a list of intentions and recalled them after a retention interval filled with a day awake or a night of sleep monitored by polysomnography. Sleep spindles and slow waves, brain oscillations involved in sleep-dependent memory consolidation, were quantified automatically using the Aseega software (Physip). Subjective sleep disturbances and markers of quality of life (psychological distress, fatigue, and well-being) were assessed by questionnaires.

Results

Greater PM performance was observed after sleep than after an equivalent period of daytime wakefulness for both groups (HC and BC). PM performance after sleep did not differ significantly between groups. Yet, BC patients reported greater sleep disturbances than HC which were related with poorer intentions retrieval, greater psychological distress, fatigue and poorer well-being. The frequency of spindles was higher and the amplitude of slow waves lower in BC patients compared to HC. However, no significant association was observed between polysomnography parameters and PM scores in the whole sample of participants.

Conclusion

Although subtle changes in brain oscillations involved in sleep-dependent memory consolidation were observed, these changes did not significantly impair overnight PM consolidation in BC patients. Nevertheless, poorer PM performance was associated with greater sleep complaints which in turn were related to poorer quality of life. Overall, these data suggest that sleep-dependent PM consolidation mechanisms are not altered in early stages BC patients not treated with chemotherapy. Further investigations are needed to understand the association between markers of quality of life and sleep-dependent memory consolidation.

Measurement, outcomes and interventions of cognitive function after breast cancer treatment: A narrative review

Cancer-related cognitive impairment (CRCI) is a common complaint in breast cancer patients, especially related to chemotherapy. It is characterized as cognitive disorders in areas of memory, attention and executive function, which can negatively affect patients' quality of life and their ability to work. While various assessment methods of CRCI cause highly diverse results in CRCI-related studies. Currently, it is not clear how cerebral structure and function change in breast cancer patients and underlying mechanisms of developing CRCI are still undefined. Intervention research is limited. This article reviews the results of CRCI-related studies and research progress and discusses the advantages and limits of various methods. Besides, the mechanisms and intervention strategies are reviewed.

Prospective memory and brain metastases: a relevant target for rehabilitation in post-operative patients?

PURPOSE

The study investigated the prospective memory (PM) functioning among patients with brain metastases (BM), eligible for neurosurgy/radiosurgery, and its relationships with depression and quality of life (QoL).

METHODS

This case-healthy-control, cross-sectional study, comprised 160 participants, including 49 patients with BM from various cancers treated with neurosurgery or radiosurgery. They were compared with 111 matched controls on a set of neuropsychological tests, including the MoCA global cognitive test and an experimental PM task 'PROMESSE'. Participants also completed a depression scale (BDI-II), a generic (SF-12) and a specific (QLQ-C30) QoL instrument for cancer patients. Multivariate analyses were conducted on various PM outcomes, in particular on event-based (EBPM) and time-based (TBPM) PM performances.

RESULTS

After adjusting for age and socio-cultural level, patients with BM performed worse than the control on the PM task (p < .0001) [OR 1.05; 95%CI (1.01-1.08)], whatever the location of BM (frontal versus temporal lobe). Patients with infratentorial BM exhibited better TBPM performances than patients with supratentorial BM (p = .02). The global PM performance was positively correlated with the MoCA (r = .45) and the SF-12 global score (r = .34), and negatively with the BDI-II score (r = - .20), the number of BM (r = - .34) and the volumetric of the BM (r = - 29). The TBPM performance was linked to the global QoL (r = .40) in patients.

CONCLUSION

The study showed a significant PM deficit in patients with BM eligible for a neurosurgy/radiosurgery, which is linked to damaged QoL and which likely maintains some depressive affects. Prospective memory rehabilitation program should especially focus on TBPM for post-operative patients with BM.

Depression involved in self-reported prospective memory problems in survivors of breast cancer who have received chemotherapy

To investigate the relationship between depression and the self-reported prospective memory (SPM) problems in breast cancer survivors who have received chemotherapy.Sixty-three breast cancer patients were administered with self-rating depression scale (SDS) and the prospective memory questionnaire as part of extensive neuropsychological assessments before and after chemotherapy. The performance of SDS and SPM were compared, with the level of significance set at P < .05.Compared with the group before chemotherapy, there is a significant difference on the SPM score (t = 6.069, P = .000) in breast cancer patients after chemotherapy. Further, there is also a significant difference on the SPM score (t = -4.348, P = .000) between the patients with and without depression group after chemotherapy.The present result indicated that the depression in breast cancer survivors after chemotherapy may be involved in their chemotherapy-induced SPM impairment.

Impact of breast cancer on prospective memory functioning assessed by virtual reality and influence of sleep quality and hormonal therapy: PROSOM-K study

BACKGROUND

Breast cancer (BC) is the most frequent cancer in women with more than 70% of BC patients being treated with hormonal therapy (HT). Among these patients, some report difficulties in remembering what they are supposed to do at the right moment, referring to prospective memory (PM). PM is essential for autonomy and medical adherence of patients, and requires an ecological assessment. Virtual reality, that recreates naturalistic environment, seems to be a promising method to evaluate PM. Several BC patients also report sleep disturbances. Given the role of sleep on memory consolidation, it is imperative to explore the influence of sleep quality on PM in BC patients treated with HT. The purpose of PROSOM-K study is to assess PM functioning using virtual reality and sleep quality in BC treated or not with HT.

METHODS

PROSOM-K is a prospective study including post-menopausal BC patients ≤70 years old treated with radiotherapy (n = 25) or with radiotherapy and HT (n = 25), and healthy post-menopausal women (n = 25) matched for age and education. PM will be assessed using a virtual reality based task. Other cognitive functions and psychosocial factors will be assessed with validated questionnaires and neuropsychological tests. The study is divided in 3 sessions: a session of familiarisation with the virtual environment and the PM task: a day-time session during which participants learn intentions during the morning and recall them in the evening; and a night-time session during which participants learn intentions in the evening and recall them the following morning. Women will be monitored by wrist actigraphy; during the night-time session, objective sleep quality and quantity will be measured by polysomnography.

DISCUSSION

This is a novel study aiming to assess PM using virtual reality, coupled with the evaluation of other cognitive functions. Polysomnographic study of sleep will provide further information about architectural sleep disturbances in BC. Association between sleep architecture parameters and PM mechanism in BC women treated with HT will be described in detail. We expect our results will provide knowledge for patients and clinicians and further help to improve patient care and cognitive therapy.

TRIAL REGISTRATION

NCT03420105 , registered: January 10, 2018.

Altered resting-state hippocampal functional networks associated with chemotherapy-induced prospective memory impairment in breast cancer survivors

In this study, we aimed to investigate the intrinsic hippocampal functional connectivity (FC) network and its relationship with prospective memory in patients with breast cancer suffering from chemotherapy-induced cognitive impairment (CICI). Thirty-four breast cancer patients before and after adjuvant chemotherapy (CB and CC, respectively) and 31 age- and education-matched cognitively normal (CN) women were recruited and subjected to a prospective memory task and a resting-state functional magnetic resonance imaging scan. Seed-based functional connectivity analysis was used to compare the hippocampal FC networks between CC and CN groups. Partial correction analysis was used to examine the association between the hippocampal FC network and prospective memory in the CC group. The cancer group that underwent chemotherapy obtained significantly poorer scores than the CN group on mini-mental state examination, verbal fluency test, digit span, and prospective memory examination. Compared to the CN group, CC group showed increased hippocampal connectivity in the frontal and parietal cortex, precuneus, posterior cingulate cortex, and the cerebellum. In addition, the increasing hippocampal FC networks were negatively correlated with prospective memory performance in the CC group. These findings suggest maladaptive hippocampal functioning as a mechanism underlying the impairment of prospective memory in patients experiencing CICI.

Correspondence between Subjective and Objective Cognitive Functioning Following Chemotherapy for Breast Cancer

This study examined subjective and objective cognitive functioning in 26 female breast cancer survivors (BCS) who received chemotherapy treatment that finished .5 to 5 years prior to testing and compared their results to 25 demographically matched women with no history of cancer. Participants were assessed on prospective memory (PM) tasks; neuropsychological tests of processing speed, attentional flexibility with greater cognitive load, executive function, and verbal memory; self-report measures of cognitive dysfunction and PM failures; and distress. The BCS group showed significantly slower speed of processing and reduced attentional flexibility, and reported significantly more cognitive complaints and PM failures than the control group on five of six self-report measures. The groups did not differ on other PM or neuropsychological measures or on a measure of distress. Subjective cognition correlated with some neuropsychological tests and with a virtual reality PM task. Objective cognitive impairments were associated with reduced quality of life in the BCS group. The results provide some evidence of both self-reported impairment and objective cognitive dysfunction following chemotherapy treatment.

Metamemory function in chemotherapy-treated patients with breast cancer: an explanation for the dissociation between subjective and objective memory measures?

BACKGROUND

The purpose of this study was to determine if a deficit in metamemory could account for the disparity between subjective and objective measures of memory function commonly observed in patients with breast cancer (BC). Metamemory refers to the awareness and management of one's own memory function. It is considered an aspect of executive functioning, one of the most common areas of cognitive compromise associated with BC and its treatment.

METHODS

Fifty-four women with early stage BC who had recently completed chemotherapy were compared with 54 healthy women matched on age and education. Cognitive function was objectively assessed with a neuropsychological test battery and subjectively assessed with the Functional Assessment of Cancer Therapy Cognitive Scale. Metamemory was assessed with a Feeling of Knowing (FOK) paradigm.

RESULTS

The patients with BC scored significantly lower than the controls on both the objective and subjective cognitive measures, as well as on free recall and recognition conditions of the FOK, suggesting some decline in primary memory functions such as working memory, encoding, and retrieval. The discrepancy between the objective and subjective measures was larger in the patients with BC than in the controls, but there was no difference between the groups on the FOK metamemory index.

CONCLUSIONS

Discrepancy in objective and subjective measures of cognition in patients with BC cannot be accounted for in terms of a deficit in meta-cognition. Objective and subjective measures are complementary, and a comprehensive cognitive assessment in patients with BC requires both. Copyright © 2015 John Wiley & Sons, Ltd.

PROspective MEmory Training to improve HEart failUre Self-care (PROMETHEUS): study protocol for a randomised controlled trial

Background

Cognitive impairment is seen in up to three quarters of heart failure (HF) patients and has a significant negative impact on patients’ health outcomes. Prospective memory, which is defined as memory to carry out future intentions, is important for functional independence in older adults and involves application of multiple cognitive processes that are often impaired in HF patients. The objective of this study is to examine the effects of prospective memory training on patients’ engagement in HF self-care and health outcomes, carer strain and quality of life.

Methods/design

The proposed study is a randomised, controlled trial in which 200 patients diagnosed with HF, and their carers will be recruited from 3 major hospitals across Melbourne. Eligible patients with HF will be randomised to receive either: 1) The Virtual Week Training Program - a computerised prospective memory (PM) training program (intervention) or 2) non-adaptive computer-based word puzzles (active control). HF patients’ baseline cognitive function will be compared to a healthy control group (n = 60) living independently in the community. Patients will undergo a comprehensive assessment of PM, neuropsychological functioning, self-care, physical, and emotional functioning. Assessments will take place at baseline, 4 weeks and 12 months following intervention. Carers will complete measures assessing quality of life, strain, perceived control in the management of the patients’ HF symptoms, and ratings of the patients’ level of engagement in HF self-care behaviours.

Discussion

If the Virtual Week Training Program is effective in improving: 1) prospective memory; 2) self-care behaviours, and 3) wellbeing in HF patients, this study will enhance our understanding of impaired cognitive processes in HF and potentially is a mechanism to reduce healthcare costs.

Trial registration

Australian New Zealand Clinical Trials Registry #366376; 27 May 2014. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366376&isClinicalTrial=False.

A Systematic Review of the Safety and Effect of Neurofeedback on Fatigue and Cognition

BACKGROUND

Many cancer survivors continue to experience ongoing symptoms, such as fatigue and cognitive impairment, which are poorly managed and have few effective, evidence-based treatment options. Neurofeedback is a noninvasive, drug-free form of brain training that may alleviate long-term symptoms reported by cancer patients.

OBJECTIVE

The purpose of this systematic review of the literature was to describe the effectiveness and safety of neurofeedback for managing fatigue and cognitive impairment.

METHODS

A systematic review of the literature was conducted using Joanna Briggs Institute (JBI) methodology. A comprehensive search of 5 databases was conducted: Medline, CINAHL, AMED, PsycInfo, and Embase. Randomized and nonrandomized controlled trials, controlled before and after studies, cohort, case control studies, and descriptive studies were included in this review.

RESULTS

Twenty-seven relevant studies were included in the critical appraisals. The quality of most studies was poor to moderate based on the JBI critical appraisal checklists. Seventeen studies were deemed of sufficient quality to be included in the review: 10 experimental studies and 7 descriptive studies. Of these, only 2 were rated as high-quality studies and the remaining were rated as moderate quality. All 17 included studies reported positive results for at least one fatigue or cognitive outcome in a variety of populations, including 1 study with breast cancer survivors. Neurofeedback interventions were well tolerated with only 3 studies reporting any side effects.

CONCLUSIONS

Despite issues with methodological quality, the overall positive findings and few reported side effects suggest neurofeedback could be helpful in alleviating fatigue and cognitive impairment. Currently, there is insufficient evidence that neurofeedback is an effective therapy for management of these symptoms in cancer survivors, however, these promising results support the need for further research with this patient population. More information about which neurofeedback technologies, approaches, and protocols could be successfully used with cancer survivors and with minimal side effects is needed. This research will have significance to nurses and physicians in oncology and primary care settings who provide follow-up care and counseling to cancer survivors experiencing debilitating symptoms in order to provide information and education related to evidence-based therapy options.