Neuropsychological and Emotional Functioning in Patients with Cushing's Syndrome

Comparable cognitive impairment was detected in MACS and CS and alleviated after remission of hypercortisolism in MACS

Context

Few studies have directly compared the cognitive characteristics of patients with mild autonomous cortisol secretion (MACS) and Cushing's syndrome (CS). The effect of surgical or conservative treatment on cognitive function in patients with MACS is still unclear.

Objective

To compare the differences in cognitive function between patients with MACS and CS and evaluate the effect of surgery or conservative treatment on cognitive function.

Methods

We prospectively recruited 59 patients with nonfunctional adrenal adenoma (NFA), 36 patients with MACS, and 20 patients with adrenal CS who completed the global cognition and cognitive subdomains assessments. Seventeen MACS patients were re-evaluated for cognitive function after a 12-month follow-up period; of these, eleven underwent laparoscopic adrenalectomy and six received conservative treatment.

Results

Patients with MACS and CS performed worse in the global cognition and multiple cognitive domains than those with NFA (all P<0.05). No statistical difference was found in cognitive functions between patients with MACS and CS. Logistic regression analysis showed that patients with MACS (odds ratio [OR]=3.738, 95% confidence intervals [CI]: 1.329-10.515, P=0.012) and CS (OR=6.026, 95% CI: 1.411-25.730, P=0.015) were associated with an increased risk of immediate memory impairment. Visuospatial/constructional, immediate and delayed memory scores of MACS patients were significantly improved at 12 months compared with pre-operation in the surgical treatment group (all P<0.05), whereas there was no improvement in the conservative treatment group.

Conclusion

Patients with MACS have comparable cognitive impairment as patients with CS. Cognitive function was partially improved in patients with MACS after adrenalectomy. The current data support the inclusion of cognitive function assessment in the clinical management of patients with MACS.

Reversibility of Impaired Large-Scale Functional Brain Networks in Cushing's Disease after Surgery Treatment: A Longitudinal Study

INTRODUCTION

Chronic exposure to excessive endogenous cortisol leads to brain changes in Cushing's disease (CD). However, it remains unclear how CD affects large-scale functional networks (FNs) and whether these effects are reversible after treatment. This study aimed to investigate functional network changes of CD patients and their reversibility in a longitudinal cohort.

METHODS

Active CD patients (N = 37) were treated by transsphenoidal pituitary surgery and reexamined 3 months later. FNs were computed from resting-state fMRI data of the CD patients and matched normal controls (NCs, N = 37). A pattern classifier was built on the FNs to distinguish active CD patients from controls and applied to FNs of the CD patients at the 3-month follow-up. Two subgroups of endocrine-remitted CD patients were identified according to their classification scores, referred to as image-based phenotypically (IBP) recovered and unrecovered CD patients, respectively. The informative FNs identified by the classification model were compared between NCs, active CD patients, and endocrine-remitted patients as well as between IBP recovered and unrecovered CD patients to explore their functional network reversibility.

RESULTS

All 37 CD patients reached endocrine remission after treatment. The classification model identified three informative FNs, including cerebellar network (CerebN), fronto-parietal network (FPN), and default mode network. Among them, CerebN and FPN partially recovered toward normal at 3 months after treatment. Moreover, the informative FNs were correlated with 24-h urinary-free cortisol and emotion scales in CD patients.

CONCLUSION

These findings suggest that CD patients have aberrant FNs that are partially reversible toward normal after treatment.

Dynamic functional connectivity changes associated with psychiatric traits and cognitive deficits in Cushing's disease

Cushing's disease is a rare neuroendocrine disorder with excessive endogenous cortisol, impaired cognition, and psychiatric symptoms. Evidence from resting-state fMRI revealed the abnormalities of static brain connectivity in patients with Cushing's disease (CD patients). However, it is unknown whether the CD patients' dynamic functional connectivity would be abnormal and whether the dynamic features are associated with deficits in cognition and psychopathological symptoms. Here, we evaluated 50 patients with Cushing's disease and 57 healthy participants by using resting-state fMRI and dynamic functional connectivity (dFNC) approach. We focused on the dynamic features of default mode network (DMN), salience network (SN), and central executive network (CEN) because these are binding sites for the cognitive-affective process, as well as vital in understanding the pathophysiology of psychiatric disorders. The dFNC was further clustered into four states by k-mean clustering. CD patients showed more dwell time in State 1 but less time in State 4. Intriguingly, group differences in dwell time in these two states can explain the cognitive deficits of CD patients. Moreover, the inter-network connections between DMN and SN and the engagement time in State 4 negatively correlated with anxiety and depression but positively correlated with cognitive performance. Finally, the classifier trained by the dynamic features of these networks successfully classified CD patients from healthy participants. Together, our study revealed the dynamic features of CD patients' brains and found their associations with impaired cognition and emotional symptoms, which may open new avenues for understanding the cognitive and affective deficits induced by Cushing's disease.

Impaired Cognitive Function in Patients With Autonomous Cortisol Secretion in Adrenal Incidentalomas

CONTEXT

Glucocorticoids have potent effects on the central nervous system. However, while patients with Cushing syndrome frequently report impairments in cognitive function, studies investigating cognitive function in patients with autonomous cortisol secretion (ACS) in adrenal incidentalomas (AIs) are scarce.

OBJECTIVE

The aim of the present study was to evaluate neurocognitive function in patients with ACS.

METHODS

We prospectively recruited 63 patients with AI, 36 patients with nonfunctional adrenal adenoma (NFA) (46.5 ± 10.5 years), and 27 patients with ACS (48.6 ± 9.1 years); these patients underwent a battery of validated neuropsychological tests. ACS was diagnosed when serum cortisol levels after a 1-mg dexamethasone suppression test (cortisol1 mg DST) ≥ 50 nmol/L.

RESULTS

Patients with ACS had higher frequency of subjective memory complaints (40.7% vs 13.9%, P < 0.05) and higher proportion of mild cognitive impairment (22.2% vs 2.8%, P < 0.05) than patients with NFA. Furthermore, patients with ACS had worse performance on working memory and the visuospatial/constructional domain than patients with NFA (all P < 0.05). Serum cortisol1 mg DST was negatively correlated with working memory and visuospatial/constructional domains (r = -0.307 and -0.306, respectively, all P < 0.05). Performance on working memory and visuospatial/constructional domains gradually deteriorated with increases in serum cortisol1 mg DST (all P values for trend < 0.05). Multivariate linear regression analysis showed that serum cortisol1 mg DST was a significant risk factor for impairment of working memory and visuospatial/constructional domains (B = -0.006 and -0.043, respectively, all P < 0.05).

CONCLUSION

This study is the first to report that ACS is accompanied by impaired cognitive function. Consequently, cognitive function assessment should be incorporated into the clinical evaluation of patients with ACS.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05357456.

Evaluating Patient-Reported Outcomes in Cushing's Syndrome

The importance of the patient's perspective on disease has increasingly gained traction among clinical investigators and clinicians. Patient-reported outcomes (PROs) are those which pertain to a patient's health, quality of life, or functional status (associated with health care or treatment) that are reported directly by the patient, without interpretation by a clinician. In this article, we will review PROs as they relate to the signs, symptoms, health-related quality of life, and comorbidities of active Cushing's syndrome (CS), and CS after treatment with surgery, radiotherapy, and medical therapy. We will explore long-term outcomes in the setting of remission, persistence, and recurrence in this population.

Long-term effects of glucocorticoid excess on the brain

The metabolic and cardiovascular clinical manifestations in patients with Cushing's syndrome (CS) are generally well known. However, recent studies have broadened the perspective of the effects of hypercortisolism, showing that both endogenous and exogenous glucocorticoid excess alter brain functioning on several time scales. Consequently, cognitive deficits and neuropsychological symptoms are highly prevalent during both active CS and CS in remission, as well as during glucocorticoid treatment. In this review, we discuss the effects of endogenous hypercortisolism and exogenously induced glucocorticoid excess on the brain, as well as the prevalence of cognitive and neuropsychological deficits and their course after biochemical remission. Furthermore, we propose possible mechanisms that may underly neuronal changes, based on experimental models and in vitro studies. Finally, we offer recommendations for future studies.

Gene expression changes in the brain of a Cushing's syndrome mouse model

Excess glucocorticoid exposure affects emotional and cognitive brain functions. The extreme form, Cushing's syndrome, is adequately modelled in the AdKO_2.0 mouse, consequential to adrenocortical hypertrophy and hypercorticosteronemia. We previously reported that the AdKO_2.0 mouse brain undergoes volumetric changes that resemble closely those of Cushing's syndrome human patients, as well as changes in expression of glial related marker proteins. In the present work, the expression of genes related to glial and neuronal cell populations and functions was assessed in regions of the anterior brain, hippocampus, amygdala and hypothalamus. Glucocorticoid target genes were consistently regulated, including CRH mRNA suppression in the hypothalamus and induction in amygdala and hippocampus, even if glucocorticoid receptor protein was downregulated. Expression of glial genes was also affected in the AdKO_2.0 mouse brain, indicating a different activation status in glial cells. Generic markers for neuronal cell populations, and cellular integrity were only slightly affected. Our findings highlight the vulnerability of glial cell populations to chronic high levels of circulating glucocorticoids.