The Etiology and Extent of Impaired Quality of Life, Fatigue and Cognitive, Affective and Emotional Dysfunction in Patients With Cushing's Syndrome - Prospective Studies

1. Background

Endogenous Cushing's syndrome (CS) is the collective name for several rare disorders of chronic glucocorticoid (GC) excess. The most common causes are ACTH producing pituitary adenoma [Cushing's disease (CD)], cortisol producing adrenal adenoma (CPAA) and ectopic ACTH producing tumors.

Cognitive dysfunction, psychiatric disorders, fatigue, and impaired quality of life (QoL) are frequently observed in patients with active CS. Morphological changes in the central nervous system have also been reported in patients with CS, including decreased total brain volume and hippocampal formation volume compared with healthy subjects.

After successful treatment of CS, cognitive function improves according to some studies while others have found no change from pre-treatment levels. Increased brain volume has also been reported following treatment, although not to the levels of a normal control group.

Various aspects of the neurocognitive consequences of hypercortisolism have been studied in recent years. However, a major limitation of most previous studies is the small sample size. Longitudinal research data is sparse. A further limitation is that CS is a heterogeneous disease with several etiologies, varied clinical findings at presentation and varying outcome after treatment. Consequently, and since CS is a rare syndrome, the number of patients needed to be studied is too large for a single center. A collaborative multi-centre effort is therefore a desirable approach. 2. Aim