Research On Cognitive Dysfunction In Prolactinoma Patients Based On Behavioral Performance,Event-related Potentials And Neural Oscillations

Background:Cognitive dysfunction in patients with pituitary adenomas has been reported more and more in recent years,which has affected the quality of life of patients to varying degrees.The compressive effects of the tumor itself on surrounding brain structures and the abnormal hormonal status of functional pituitary adenomas are the most possibly potential pathogenic factors.Existing studies had not conducted a controlled analysis of both factors meanwhile adopted mostly subjective neuropsychological scales to evaluate the cognitive status.Thus,the conclusion on cognitive status in patients with pituitary adenomas was not clear until now.In this study,the most common subtype(prolactinomas)was selected as the research object,and high temporal resolution and quantifiable event-related potentials and related analysis techniques were adopted as research methods.The purpose of the above study design was to investigate the cognitive dysfunction and possible mechanisms in patients with prolactinomas.Chapter 1 Selective attention and interference control dysfunction in patients with prolactinomasObjectives:To explore the changes of selective attention and interference control in patients with prolactinomas and their correlation with prolactin(PRL)levels.Methods:The behavioral and continuous EEG data of all participants in the enrolled prolactinomas group and healthy controls(HCs)group were recorded when they performed the revised arrow Eriksen Flanker paradigm.The behavioral performance of accuracy and reaction time(RT),and electrophysiological indices of ERP components and event-related spectrum perturbation(ERSP)power were statistically compared,and the correlations between the above indices and PRL levels were tested.Results:Behaviorally,the RT in the prolactinomas group was significantly longer than that of the HCs under both types of stimuli.In terms of ERP components,the peak amplitude of N2 in the prolactinomas group was significantly higher than that in the HCs group,while the mean amplitudes of P2 and P3 were significantly lower than those in the HCs group.In terms of ERSP power,the theta band ERS power in the prolactinomas group was significantly lower than that in the HCs group,while the alpha band ERD power was significantly higher.Correlation analysis showed that RPL levels were significantly correlated with RT,P3 mean amplitude,N2 peak amplitude under incongruent stimuli,and theta band ERS power in the prolactinomas group.Chapter 2 Working memory dysfunction in patients with prolactinomas Objectives:To explore the changes of working memory(WM)in patients with prolactinomas and their correlation with PRL levels.Methods:The behavioral and continuous EEG data of all participants in the enrolled prolactinomas group and healthy controls(HCs)group were recorded when they performed the forward digit span test.The behavioral performance of accuracy,electrophysiological indices of ERP components and ERSP power were statistically compared,and the correlations between the above indices and PRL levels were tested.Results:Behaviorally,the accuracy was lower in the prolactinomas group compared with HCs in both lengths of numbers.In terms of ERP components,the mean amplitudes of P2 and P3b in the prolactinomas group were significantly lower than those in the HCs group.In terms of ERSP power,the alpha band ERD power in the HCs was significantly higher than that of the prolactinomas group under the medium and high WM load levels,while no group difference was founded in the comparison of theta ERS power.Correlation analysis showed that there was a significant correlation between the mean amplitudes of P3b and PRL levels in the prolactinomas group.Conclusions:Multidimensional evidence revealed varying degrees of cognitive impairments in selective attention and interference control abilities in patients with prolactinomas.The cognitive toxicity of over-secreting PRL levels on the nervous system may be a possible mechanism of cognitive deficits and deserve further investigation.Meanwhile,changes in behavioral and neuroelectrophysiological indices could be the potential biomarkers of cognitive dysfunction in patients with prolactinomas.