• Prolactin levels negatively correlated with prolactinomas’ executive controls. • Prolactin levels mediated the correlation between frontal theta activity and inhibition control ability. • Prolactinomas exhibited decreased frontal theta power in Go/Nogo task. • The frontal theta oscillation was highlighted as the electrophysiological markers of the impaired inhibitory control in prolactinomas.

Cognitive abilities are impaired in patients with pituitary adenoma. However, studies on attention processing impairment in preoperative patients and attention processing recovery after transsphenoidal adenomectomy are lacking. The study aims to identify the electrophysiological change that relates to attention processing in pituitary patients before and after treatment. Twenty five preoperative pituitary patients and 25 follow-up postoperative patients were recruited. 27 healthy controls (HCs) were matched to the patients with age, gender, and education. Event-related potentials were used to investigate the attention processing in the preoperative patients, postoperative patients, and HCs. Across three groups, all emotional stimuli evoked P200 components. Compared with the HCs or postoperative patients, the amplitudes of P200 in the preoperative patients were higher. Moreover, The amplitudes of P200 decreased in the postoperative patients, which were similar to that in the HCs. The attention processing was improved after surgery, but no significant differences were detected between the postoperative patients and HCs. Abnormal hormone levels may be relevant to the factor that impair attention processing. Compared with that of the HCs and postoperative patients, the P200 component elicited by negative stimuli is higher in preoperative patients, which may illustrate compensatory activity after attention impairments. Furthermore, these data indicate that improvements in attention processing may be attributed to the amelioration of endocrine disorders. This study shows that the P200 component may be used to diagnose attention processing in preoperative pituitary patients and prove the improvement of attention processing in postoperative patients.

Evidence showed impaired cognitive ability of patients with pituitary adenoma as an intracranial tumor. In the present study, we investigated the preattentive processing of emotional faces in pituitary adenoma patients by recording and analyzing the visual mismatch negativity elicited by deviant emotional faces. In the normal control group, deviant emotional faces elicited expression-related mismatch negativity (EMMN), with a more pronounced negative waveform for sad than happy face conditions. Compared with the normal group, EMMN related to sad faces was smaller in patients, whereas the EMMN related to happy faces remained the same. These data indicate the functional dysfunction of negative emotional processing at the preattentive stage of information processing in pituitary adenoma patients.

Injured cognitive abilities have been reported in patients with pituitary adenoma. However, to date, few researchers have directly investigated the electrophysiological study of inhibitory control function of pituitary patients both pre- and postsurgery. Thus, this study aimed to identify the factors affecting the inhibitory control function of pituitary patients. Thirty presurgery pituitary patients were recruited and 26 patients of them completed the postsurgery follow-up. Thirty healthy people were recruited for control group. Visual Go/Nogo tasks were carried out by the patients and controls to assess the inhibitory control function before surgery and 6 months after the surgery, respectively. The function of inhibitory control was analyzed with the components of N2 and P3. Across 3 groups, Nogo stimuli evoked larger frontal-central N2nogo and P3nogo than Go stimuli did. Furthermore, N2d of presurgery patients (−1.14 μV) and postsurgery patients(−0.61 μV) were significantly decreased compared with that of control group (−3.09 μV), F(2, 83) = 13.92, P < .01, whereas no difference was detected between pre- and postsurgery groups. There was no remarkable difference in the amplitude of P3d among the 3 groups, F(2, 83) = 0.19, P > .05. With regard to the amplitude of P3 for Go condition, The P3 amplitude of healthy group (4.38 μV) was larger than both pre- and postsurgery (1.00 μV and 3.01 μV). With regard to the amplitude of P3 for Nogo condition, The P3 amplitude of healthy group (5.25 μV) was larger than both pre- and postsurgery groups (2.35 μV and 4.18 μV). These results indicated that presurgery patients showed the dysfunction of inhibition, due to the nerve tissue damage or brain structure alteration caused by the presurgery physical pressure from tumor and abnormal hormone levels. Postsurgery patients showed a tendency toward recovery, but there was no obvious improvement in the inhibitory control function after successful treatments.

Prolactinomas have been reported to impair cognition in broad aspects. However, few studies investigated the influence of prolactinomas on cognitive flexibility never mentioning the underlying neural and electrophysiological mechanism. We recorded scalp electroencephalography (EEG) in a colour-shape switching task. Patients with prolactinomas showed longer reaction time in switch trials and larger switch costs relative to healthy controls (HCs). Compared to HCs who showed stronger frontal theta activity in switch trials, the generally weak frontal theta activity in patients implied that they could not afford the executive control to configure task sets. Meanwhile, machine-learning based classification revealed that patients manifested non-selective brain patterns in response to different task types (colour vs. shape task) and different task states (switch vs. repeat state), which collectively suggested the cognitive dysfunction in preparation for a changing environment. Compared to HCs who showed stronger frontoparietal synchronization in switch trials, this enhanced frontoparietal connectivity was disrupted among patients with severe prolactinomas. This finding implicated greater hyperprolactinemia was linked to a larger decrease in cognitive performance. Taken together, the present study highlighted frontal theta power, and frontoparietal connectivity at theta band as the electrophysiological markers of the impaired cognitive flexibility and task control in patients with prolactinomas.

Prolactinomas have been reported for the failure of cognitive functions. However, the electrophysiological mechanisms of attention processing in prolactinomas remain unclear. In a visual mission, we monitored the scalp electroencephalography (EEG) of the participants. Compared with the healthy controls (HCs), larger frontoparietal theta and alpha coherence were found in the patients, especially in the right-lateralized hemisphere, which indicated a deficit in attention processing. Moreover, the frontoparietal coherence was positively correlated with altered prolactin (PRL) levels, implying the significance of PRL for adaptive brain compensation in prolactinomas. Taken together, this research showed the variations in attention processing between the HCs and prolactinomas. The coherence between frontal and parietal regions may be one of the possible electrophysiological biomarkers for detecting deficient attention processing in prolactinomas.