Cushing s syndrome

Cushing s disease Cushing s syndrome Cushioning applications... 

Cushing s syndrome a disease caused by the overproduction of endogenous glucocorticoids... 

Example, Bartter s or Gitelman s syndrome, Cushing s syndrome, hyperaldosteronism (1° or 2°), and Liddle s syndrome... 

Cushing s syndrome and other glucocorticoid excess states... 

Alzheimer s disease Cerebral infarction Cerebral tumors Closed head injury Cushing s syndrome Hemodialysis Hepatic encephalopathy Huntington s disease Hyperthyroidism Ictal or post-ictal mania Multiple sclerosis Neurosyphilis... 

Recognize the clinical presentation of Cushing s syndrome and the physiologic consequences of cortisol excess. 

Recommend strategies to prevent the development of Cushing s syndrome associated with exogenous glucocorticoid administration. 

Recommend therapy monitoring parameters for patients with Cushing s syndrome. 

Patients with Cushing s syndrome owing to endogenous or exogenous glucocorticoid excess typically present with similar clinical manifestations. 

Surgical resection is considered the treatment of choice for Cushing s syndrome from endogenous causes if the tumor can be localized and if there are no contraindications. 

Monitor for adverse reactions from hydrocortisone administration. Glucocorticoid therapy at physiologic replacement doses should not lead to the development of Cushing s syndrome. However, careful monitoring should still be performed. Use the smallest effective dose. 

Fhtients may require a lower dose of glucocorticoid than those with primary adrenal insufficiency. Some patients will only require glucocorticoid replacement temporarily, which can be discontinued after recovery of the HPA axis (e.g., drug-induced adrenal insufficiency, adrenal insufficiency following treatment for Cushing s syndrome). 

ACTH-secreting pituitary tumor (Cushing s disease)—70% of cases of endogenous Cushing s syndrome... 

ACTH-secreting non-pituitary tumors (ectopic ACTH syndrome)—15% of cases of endogenous Cushing s syndrome usually from small cell lung carcinoma, bronchial carcinoids, pheochromocytoma, or thymus, pancreatic, ovarian, or thyroid tumor. The tumor is usually disseminated (difficult to localize). 

Drug-Induced Cushing s Syndrome (ACTH-independent)—most common cause of Cushing s syndrome... 

Differential diagnoses include diabetes mellitus and metabolic syndrome because patients with these conditions share several similar characteristics with Cushing s syndrome patients (e.g., obesity, hypertension, hyperlipidemia, hyperglycemia, and insulin resistance). In women, the presentations of hirsutism, menstrual abnormalities, and insulin resistance are similar to those of polycystic ovary syndrome. Cushing s syndrome can be differentiated from these conditions by identifying the classic signs and symptoms of truncal obesity, "moon faces" with facial plethora, a "buffalo hump" and supraclavicular fat pads, red-purple skin striae, and proximal muscle weakness. 

True Cushing s syndrome also must be distinguished from other conditions that share some clinical presentations (as well as elevated plasma cortisol concentrations), such as depression, alcoholism, obesity, and chronic illness—the so-called pseudo-Cushing s states. 

The diagnosis of Cushing s syndrome and its etiology often are complex and generally require the involvement of endocrinologists and specialized testing centers. 

Initial screening tests to confirm the presence of hypercorti-solism and differentiate Cushing s syndrome from conditions with similar presentations include 24-hour urinary free cortisol determination and overnight low-dose dexam-ethasone suppression test (DST) (Table 42-9). 

Test Test Procedure and Measurement Rationale Typical Finding in Cushing s Syndrome Comments... 

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