Curative intent chemotherapy-induced alterations in specific qEEG markers of cognition in patients with breast cancer

Abstract

Chemotherapy-induced cognitive impairment is a gruesome outcome of chemotherapy among breast cancer survivors. Electroencephalogram (EEG) power measurement is a known sensitive neurophysiologic correlate of cancer treatment-related cognitive dysfunction. The objective of this study was to assess the changes in specific quantitative EEG markers of cognition among breast cancer patients before, immediately, and three months after chemotherapy. Twenty-three women planning to undergo adjuvant chemotherapy for breast cancer underwent EEG assessment before, immediately, and three months after chemotherapy. Repeated measures analysis of variance was used to analyse the data. Post hoc pairwise comparison was done with Bonferroni correction to determine the pair in which the difference existed. A significant increase in resting state EEG total power was observed (P = 0.012) after chemotherapy in the frontal area. The relative alpha power (RAP) significantly decreased with chemotherapy (P = 0.039), with post hoc pairwise comparison with Bonferroni correction revealing the significant decline to be present immediately after chemotherapy (P = 0.036) only over the posterior channels. Furthermore, the alpha-to-theta ratio (ATR) over posterior areas decreased (P = 0.012) both after completion of chemotherapy (P = 0.039) as well as three months after chemotherapy (P = 0.048). However, similar changes were not observed over frontal areas. Chemotherapy induces enhanced frontal power with a coincidental decline in RAP and ATR in the posterior areas.