Neurobehavioral functioning of adults with pituitary disease

Glymphatic transport is reduced in rats with spontaneous pituitary tumor

Background and objective

Pituitary tumor in patients induces adverse alterations in the brain, accompanied by cognitive deficits. Dysfunction of glymphatic waste clearance results in accumulation of neurotoxic products within the brain, leading to cognitive impairment. However, the status of glymphatic function in the brain with pituitary tumor is unknown. Using magnetic resonance imaging (MRI) and an advanced mathematical modeling, we investigated the changes of glymphatic transport in the rats carrying spontaneous pituitary tumor.

Methods

Rats (22-24 months, female, Wistar) with and without pituitary tumor (n = 7/per group) underwent the identical experimental protocol. MRI measurements, including T2-weighted imaging and dynamic 3D T1-weighted imaging with intracisternal administration of contrast agent, were performed on each animal. The contrast-induced enhancement in the circle of Willis and in the glymphatic influx nodes were observed on the dynamic images and verified with time-signal-curves (TSCs). Model-derived parameters of infusion rate and clearance rate that characterize the kinetics of glymphatic tracer transport were evaluated in multiple representative brain regions.

Results

Our imaging data demonstrated a higher incidence of partially enhanced circle of Willis (86 vs. 14%; p < 0.033) and a lower incidence of enhancement in glymphatic influx nodes of pituitary (71 vs. 100%) and pineal (57 vs. 86%) recesses in the rats with pituitary tumor than in the rats with normal appearance of pituitary gland, indicating an intensification of impaired peri-vascular pathway and impeded glymphatic transport due to the presence of pituitary tumor. Consistently, our kinetic modeling and regional cerebral tissue quantification revealed significantly lower infusion and clearance rates in all examined regions in rats with spontaneous pituitary tumor than in non-tumor rats, representing a suppressed glymphatic transport in the brain with pituitary tumor.

Conclusion

Our study demonstrates the compromised glymphatic transport in the rat brain with spontaneous pituitary tumor. The reduced efficiency in cerebral waste clearance increases the risk for neurodegeneration in the brain that may underlie the cognitive impairment commonly seen in patients with pituitary tumors.

Hyperprolactinemia Associated with Attentional Processing and Interference Control Impairments in Patients with Prolactinomas

The cognitive impairment of pituitary adenomas (PAs) has received increasing attention. Hyperprolactinemia and tumor mass effect are the potential causes. The aim of this study was to identify possible cognitive impairment and to further explore the correlation between these indices and prolactin (PRL) levels, based on the control of tumor size. Twenty-seven patients with prolactinomas (patient group) and twenty-six matched health control group (HC group) were enrolled in this study. All participants performed the flanker task while we continuously recorded electroencephalography data. On the behavioral performance level, patients showed a significantly slower reaction time (RT) in both flanker types. Concerning the event-related potentials level, patients elicited reduced P2 and enhanced N2 amplitudes compared with the HC group, suggesting an impairment of attentional processing (P2) and conflict monitoring (N2). Moreover, the patient group also induced lower P3 amplitudes relative to the HC group in both types, indicating that there were deficits in attentional resource allocation ability. We also found a significant correlation between the P3 amplitudes and incongruent condition RTs, as well as the subsequent PRL levels in the patient group. In conclusion, this is an innovative study that reveals the impaired cognition abilities in prolactinomas, and also proposes the possible cognitive toxicity of oversecreted PRL levels, which provides evidence for further research on the cognitive decline in PAs.

Response Activation and Inhibition in Patients With Prolactinomas: An Electrophysiological Study

Impairment of executive function has been reported in patients with prolactinomas. However, few studies have investigated the electrophysiological mechanisms of response activation and response inhibition in these patients. In this study, we employ an event-related potentials (ERPs) technique to quantitatively assess response activation and inhibition before and after the surgical treatment of prolactinomas. A 64-electrode electroencephalogram (EEG) skullcap was used to record the brain activity in 20 pre-operative patients, 20 follow-up post-operative patients, and 20 healthy controls (HCs) while performing the visual Go/Nogo task. As expected, we identified P300 across all study populations that could reflect response activation and inhibition. Across the three groups, the Nogo stimuli evoked larger frontal-central P300 than the Go stimuli did. In contrast, the Go trials elicited larger parietal P300 than the Nogo trials did. The peak latency of P300 was significantly delayed in both the pre-operative and the post-operative groups compared to the HCs. The amplitude of P300 in both the Go and the Nogo conditions was significantly decreased in the pre-operative patients compared with that of the HCs. At 6 months post-operatively, the prolactinoma patients showed an increase in amplitude of P300 during both the Go and the Nogo tasks. These findings indicate that the prolactinoma patients suffer from deficits in response activation and inhibition, which could be improved by surgical treatment.

The dysfunction of inhibition control in pituitary patients: evidence from the Go/Nogo event-related potential study

Pituitary tumor is an intracranial tumor; because of the development of neuroimaging technology in recent years, morbidity is likely to increase. Evidence showed impaired cognitive ability of patients with pituitary adenoma. There is evidence that neurobehavioral disorders are common in pituitary adenoma patients. This disorder is because of the cognitive and emotional function of the important functional areas of the brain oppressed and hormone imbalance. Individuals' mental activity is controlled by the brain and the abnormal mental activity is caused by both the structural abnormalities of the brain and neurochemical dysfunction. Event-related potentials have been used widely in the early assessment of cognitive functions associated with disease, taking advantage of the high temporal resolution, and then analyzing the characteristics of emotional competence from the perspective of cognitive processing. A visual Go/Nogo task was used. A larger Nogo-N2 and Nogo-P3 was found in the control group compared with the pituitary group. This reflects the nonphysiological process of conflict monitoring and inhibitory control in pituitary patients. The results also showed that the difference waves between Go and Nogo conditions (N2d and P3d) over the frontal electrode sites were more robust and earlier in the control group compared with the pituitary group, which reflects frontal dysfunction in the pituitary group. These data suggest reduced earlier and later stages of inhibitory processes in pituitary individuals, implicating the dysfunction of conflict detection and inhibitory control.

Executive functions recover earlier than episodic memory after microsurgical transsphenoidal resection of pituitary tumors in adult patients--a longitudinal study

Pituitary tumors may lead to cognitive dysfunction, and the most prevalent deficits are impaired memory and attention. To investigate whether memory and executive functions improve after surgical treatment we performed a prospective longitudinal study comprising 106 patients with pituitary tumors. Psychometric evaluation was performed with the d2-Letter Cancellation test, the Trail Making test, the Digit Span test and the Intelligence Structure test-Verbal Memory test at three timepoints: preoperatively, and at 3 months and 12 months after surgery. The preoperative and postoperative maximum suprasellar tumor extension and hormone status was assessed in all participants. The main finding was that concentration, working memory, and attentional speed improved significantly within the first 3 months after surgery (p<0.05), while improvement of episodic memory was not observed until 12 months after surgery (p<0.001). In the patients harbouring non-functioning adenomas, prolactinomas or other sellar lesions, the most important factor promoting improvement of neurocognitive function was the removal of the suprasellar tumor extension.

Predictive factors for neurocognitive function and Quality of Life after surgical treatment for Cushing's disease and acromegaly

BACKGROUND

Cushing's disease (CD) and acromegaly (AC) are associated with impairment in quality of life (QoL) and neurocognition that can persist after successful treatment.

AIM

To investigate the influence of current disease status (remission vs no remission) on neurocognitive function and QoL in treated CD and AC patients and to determine predictive factors (e.g. demographic, clinical, neurosurgical, endocrinological) for post-operative neurocognition and QoL.

SUBJECTS AND METHODS

Twenty-four CD and 37 AC patients underwent neuropsychological testing 1 to 10 yr following surgical therapy. Additionally, QoL was assessed. An overnight 2-mg dexamethasone suppression test in CD and IGF-I and GH levels in AC patients were assessed to determine current disease status. The results were compared with 28 sex-, education- and age-matched healthy controls (HC).

RESULTS

Impaired QoL was more pronounced than neurocognitive decrease in both pathologies compared to HC. This finding was independent of the current status of disease. In AC, persistent comorbidities were associated with impaired QoL (p<0.05). Older age at operation in AC patients was a significant predictor for adverse effects on psychomotor speed and attentional functions (p<0.05). In CD persistent hypocortisolism, not hypercortisolism, had adverse effects on neurocognition (p<0.01).

CONCLUSIONS

The current status of disease plays a subordinate role in postoperative outcome concerning QoL and neurocognition in either pathology. A possible explanation might be the considerably improved endocrinopathy after treatment compared to untreated patients, even if no cure is achieved. The lasting impairments might be explained by irreversible changes that have occurred during the active phase of the disease.

Quality of life in patients with pituitary tumors: a preliminary study

Patients with pituitary tumors frequently complain of quality of life problems despite normal hormonal blood levels. The goals of the study were to determine whether the sickness-related quality of life reported by these patients was poorer than that expected by the general population and whether some of these complaints and areas of dysfunction were more troublesome than others. Forty-three patients from a southeast Michigan pituitary disorders support group volunteered to complete a survey focusing on demographic, disease data and common complaints plus the Sickness Impact Profile (SIP). The results indicated that mental and physical fatigue were the most troublesome symptoms with sleep and libidinal complaints also of significant concern. The SIP indicated significant discontent among patients with regard to overall quality of life. Although this observational investigation seemed to underscore the fact that patients with pituitary tumors have a decreased quality of life despite apparently normal hormonal status, further subgroup analysis and subsequent surveys will be required to determine the actual significance of these findings.

Late effects of cancer and its treatment

OBJECTIVES

To review the common physical and psychosocial late effects of treatment in adult and childhood cancer survivors.

DATA SOURCES

Published articles and research studies.

CONCLUSIONS

More than half of individuals diagnosed with cancer can be expected to survive for more than 5 years. These survival gains have occurred because of more complex and multimodal therapy that may increase long-term toxicities.

IMPLICATIONS FOR NURSING PRACTICE

Health care providers must be familiar with these late effects to offer preventive care and health promotion strategies to this patient population.

Psychological stress and neuroendocrine function in humans: the last two decades of research

This paper reviews experimental contributions published in the last two decades and exploring the effect of emotional stress on neuroendocrine function in healthy humans. Laboratory studies allow standardization of the stressor and better control for known confounding factors. Commonly used stressors are mental arithmetics, speech tasks, the Stroop test, videogame playing, films or videotapes and interviews. Little is known about the generalizability of laboratory results, with some studies suggesting great caution in extrapolating data to real-life stress conditions. Another strategy is studying the psychoendocrine reaction to real-life stressors, such as bereavement or anticipated loss, academic examinations, everyday work and parachute jumping. The effects of different stressors on neuroendocrine axes are reviewed, as well as the influence of gender, age, personality, coping style, social support, biological and nonbiological interventions. The subjective perception of the situation is probably a main determinant of the psychoendocrine response pattern. In fact, marked variability in individual responses to a variety of stressors has frequently been observed. Evidently, the 'objective' characteristics of a given event are not the only determinants of reaction to the event itself. According to a constructivistic perspective, every given stressor has a strictly personal and idiosyncratic meaning and loses its 'objective' characteristics. Of course, biological factors may also play a part. In any case, it is mandatory to overcome a rigid dichotomy between psychological and biological processes. Dualistic conceptions which imply a determination of the physical by the psychological or vice versa should give place to a systemic conception, which implies mutual, circular interactions.