| Objective:There is evidence that chemotherapy may lead to impairment in cognitive functions of patients with cancer,mainly shows in memory,attention,executive function and information processing speed.So far,few studies have performed assessment of attentional function by using event-related potentials(ERPs).Using patients with breast cancer,the current study applied ERP technology and novelty oddball paradigm to examine the brain electrophysiological changes induced by different stimulus,aimed to detect the neuroelectrophysiology mechanism of that the adjuvant chemotherapy affects the attentional function of patients with breast cancer.Methods:30 females with breast cancer of early stage were recuited from the Department of Thyroid&Breast Surgery of Zhongshan Hospital affiliated to Dalian University.The patients had accepted surgery and would accept standard-dose chemotherapy regimens.The age range is from 30 to 60 years old,and all subjects had accepted at least 8 years education,all subjects’ sight or corrected visual acuity are normal.For each subject,the first measure was taken one day before the start of chemotherapy(T1),and the second measure was taken one week before the end of chemotherapy(T2).All subjects completed the two measures and finally 21 effective data are gained.All participants were assessed by Mini Mental State Examination(MMSE),a total score of 24 was taken as the threshold to enter the experiment.The Beck Depression Inventory(BDI),State-trait Anxiety Inventory(STAI),Fatigue Assessment Instrument(FAI)and Measurement Scale of Quality of Life for Patients with Breast Cancer(FACT-B)were used to evaluate the levels of anxiety,depression,fatigue and life quality of the subjects.Visual novelty oddball paradigm was used to elicit the neuroelectrophyology and the stimulus was presented by E-prime 2.0.This task included 4 blocks,each block had 120 trials.Between blocks the subjects can have a rest.There are three different types of stimulus:standard stimulus(80%),target stimulus(10%)and novelty stimulus(10%).To complete the entire behavior experiment need about 10 minutes.Neuroscan NuAmps40 Guide System was used to record electroencephalogram(EEG).The comparisons of the behavioral data and the scores of the questionnaires between T1 and T2 were analyzed by Paired Sample T test.ERP data induced by three different stimuli were analyzed by repeated measures analysis of variance.Spearman correlation was used between the ERP results and the psychological questionnaire results.Results:1.Results of behavior data:there was no statistical difference in reaction time and accuracy between T1 and T2.2.Results of questionnaires:there were significant statistical differences in the scores of Beck Depression Inventory(p=0.013),global Fatigue Severity subscale(p=0.024),physical well-being(p=0.015)and functional well-being(p=0.004)between T1 and T2,while there were no significant statistical differences in other subscales.3.Electrophysiological data results:Novelty stimulus:there was no main effects and interactions of time(T1 vs T2)reached significance for the latencies of P3 and P2.Between T1 and T2,ANOVAs of P3 amplitudes revealed significant main effects of site,and significant interactions of sitextime[F(5,100)=2.645,P=0.045],with further analysis showed simple main effect of time in the PZ electrode.For novelty P2 amplitude,there was a significant main effect of time[F(1,20)=5.432,p=0.030],the amplitude of P2 on T2 was larger than T1,but there was no main effect of site.Target stimulus:For target stimulus condition,there were significant main effects of site on the latency[F(5,100)=3.398,P=0.039]and amplitude[F(5,100)=10.814,P=0.000]of P3;there was no main effect of time.Standard stimulus:For N1,there was no main effect and interaction of time for latency,but the amplitude have main effect of hemisphere[F(2,40)=4.222,P=0.037].For P1,there were main effects of hemisphere on latency[F(2,40)=3.698,P=0.039]and amplitude[F(2,40)=5.463,P=0.019].4.Results of correlation:Correlation analysis between positive results of ERP and positive results of psychological questionnaire showed that the P2 amplitude of PZ electrode was significantly correlated with depression before chemotherapy.After chemotherapy the amplitude of P2 was significantly positively correlated with anxiety and depression,but there was no significant correlation between the changes in the amplitude of ERPs and the changes of depression,anxiety.Conclusion:1.After chemotherapy the amplitude of P2 in the novelty case could increase,prompting that the early stage of attentional information processing has been affected.2.After chemotherapy the amplitude of novelty P3 could increase,implying that patients might become more sensitive to novelty stimulus-patients need more efforts and pay more attention to the novelty stimulus even under the same condition,which can help them adapt to the environment,perceive danger signals.3.Chemotherapy could singnificantly increase the severity of depression and fatigue in patients with breast cancer.Patients’ physical status improved obviously with time after surgery,whereas they became more and more concerning the external image damaged by chemotherapy.4、The changes of attention function before and after chemotherapy may be result of the combination of chemotherapy and stress factors such as anxiety,depression,fatigue. |
PDF Full Text Request