Pre-Chemotherapy Differences in Visuospatial Working Memory in Breast Cancer Patients Compared to Controls: An fMRI Study

Abstract

Introduction: Cognitive deficits are a side-effect of chemotherapy, however pre-treatment research is limited. This study examines neurofunctional differences during working memory between breast cancer (BC) patients and controls, prior to chemotherapy. Methods: Early stage BC females (23), scanned after surgery but before chemotherapy, were individually matched to non-cancer controls. Participants underwent functional magnetic resonance imaging (fMRI) while performing a Visuospatial N-back task and data was analyzed by multiple group comparisons. fMRI task performance, neuropsychological tests, hospital records, and salivary biomarkers were also collected. Results: There were no significant group differences on neuropsychological tests, estrogen, or cortisol. Patients made significantly fewer commission errors but had less overall correct responses and were slower than controls during the task. Significant group differences were observed for the fMRI data, yet results depended on the type of analysis. BC patients presented with increased activations during working memory compared to controls in areas such as the inferior frontal gyrus, insula, thalamus, and midbrain. Individual group regressions revealed a reverse relationship between brain activity and commission errors. Conclusion: This is the first fMRI investigation to reveal neurophysiological differences during visuospatial working memory between BC patients pre-chemotherapy and controls. These results also increase the knowledge about the effects of BC and related factors on the working memory network. Significance: This highlights the need to better understand the pre-chemotherapy BC patient and the effects of associated confounding variables.

Associations Between Physical Fitness Indices and Working Memory in Breast Cancer Survivors and Age-Matched Controls

“…Future research should utilize larger sample sizes and/or more targeted research based on age, cancer diagnosis and treatment, to further examine the independent effects of these factors. 11 If these inter-related mechanisms are shown to lead to cognitive impairment, then interventions can be targeted towards vulnerable breast cancer survivors with the aim of preventing or even reversing further physical and cognitive decline.…”

“…For example, early stage breast cancer survivors prechemotherapy have shown slower response times and less accuracy than controls and a non-cancer control group. 11 Conversely, in a study investigating women with breast cancer receiving Lupron and healthy women 12 no significant differences were found between groups in working memory irrespective of task complexity. However, in another study while reaction times and task performance accuracy in working memory did not differ between breast cancer survivors and non-cancer controls, 13 there were significant differences in frontal lobe activation in breast cancer survivors.…”

“…38,39 In addition, the n-back has been previously used to investigate working memory in breast cancer survivors ranging in age from 42-69 years. 11,13,40,41 Each condition required participants to discriminate between 5 distinct colored shapes: blue circles, green triangles, purple stars, red squares, and orange crosses. Each participant completed two conditions of increasing difficulty: the 1-back and 2-back.…”

Neural impact of low-level alcohol use on response inhibition: An fMRI investigation in young adults

“…In the rest epochs, "REST" was presented on the screen and participants were not required to make any motor responses. This task design has been successfully used previously in several populations (Longo et al, 2013;Scherling et al, 2012;Smith et al, 2011Smith et al, , 2009.…”

Imbalance and Falls in Older Cancer Survivors

“…Changes may be subtle-Do not rely on your impression Directly ask survivor about changes in thinking and memory for higher-level activities (work, hobbies, organization of home and community activities) Focus on attention, concentration, memory, language, processing speed, ability to multitask Also consider depressive symptoms identified, but it is clear that chemotherapy is not the only culprit, 66 so consider asking all survivors if they have noticed a change in their thinking or memory. Rather than dismissing these symptoms as reflecting disordered sleep, depression, or anxiety, further investigate reports of cognitive decline made by either the survivor or his/ her proxy.…”