Neural Correlates and Functional Cognitive Maps in Breast Cancer Survivors Receiving Different Chemotherapy Regimens; a QEEG/HEG – based Investigation

Abstract

AbstractBackgroundPost-chemotherapy cognitive impairment commonly known as “chemobrain” or “chemofog” is a well-established clinical disorder affecting various cognitive domains including attention, visuospatial working memory, executive function, etc. Although several studies have confirmed the chemobrain in recent years, scant experiments have evaluated the potential neurotoxicity of different chemotherapy regimens and agents. In this study, we aimed to evaluate the extent of attention deficits, one of the commonly affected cognitive domains, among breast cancer patients treated with different chemotherapy regimens through neuroimaging techniques.MethodsBreast cancer patients treated with two commonly prescribed chemotherapy regimens, AC-T and TAC, and healthy volunteers were recruited. Near-infrared hemoencephalography (nirHEG) and quantitative electroencephalography (qEEG) assessments were recorded for each participant at rest and during task performance to compare the functional cortical changes associated with each chemotherapy regimen.ResultsThe qEEG analysis revealed increased power of high alpha/low beta or sensorimotor rhythm (SMR) frequency in left fronto-centro-parietal regions involved in dorsal and ventral attention networks (DAN and VAN) in the AC-T-treated group comparing to the TAC and control group. The AC-T group also had the highest current source density (CSD) values in DAN and VAN-related centers in 10 and 15 Hz associated with the lowest Z-scored FFT coherence in the mentioned regions.ConclusionsThe mentioned findings revealed increased cognitive workload and lack of cognitive ease in breast cancer patients treated with the AC-T regimen proposing the presumable neurotoxic sequelae of this chemotherapy regimen in comparison with the TAC regimen.