Periodic remission in Cushing's disease with paradoxical dexamethasone response: an expression of periodic hormonogenesis.

A patient with Cushing's disease due to a chromophobe adenoma was studied for 243 days before pituitary surgery and evidence for periodicity in cortisol steroid production was found with cycles occurring every 85.8 days (peak-to-peak length), associated with laboratory remissions and paradoxical response to dexamethasone. The autonomy of ACTH secretion was suggested by the nonresponsiveness to repeated lysine-vasopressin stimulation tests and lack of increase in urinary 170HCS following metyrapone. A distinct response of the hyperplastic glands (as demonstrated by percutaneous adrenal venography) was obtained on several B1-24 corticotropin stimulation. The patient's hypercortisolism disappeared following removal of the chromophobe adenoma through transphenoidal hypophysectomy.     

Cushing's disease with 'normal suppression' due to decreased dexamethasone clearance

Suppression of urinary corticosteroids during low-dose dexamethasone testing (0.5 mg every six hours eight times) has commonly been recognized as a response that excludes the diagnosis of Cushing's syndrome. Although "normal suppression" has been reported previously in Cushing's disease, rarely has an explanation been provided for this aberrant response. We report a case of proven Cushing's disease in which normal suppression was observed with low-dose dexamethasone testing. Further study suggested that this phenomenon, which is not widely recognized, was related to an abnormally decreased clearance of dexamethasone. We therefore suggest that whenever responses to testing appear discordant with the clinical index of suspicion, simultaneous plasma dexamethasone and cortisol levels should be obtained to exclude abnormalities in dexamethasone clearance.     

Cyclic Cushing's disease associated with primary empty sella

A small number of cases of Cushing's disease (CD) associated with primary empty sella (ES) have been described in the literature. Pituitary microsurgery is the recommended treatment. An alternative is chronic treatment with ketoconazole, an inhibitor of adrenal cortisol synthesis. Cyclic Cushing's syndrome is characterized by episodic cortisol hypersecretion. CD is the most frequent etiology of cyclic Cushing's syndrome. To our knowledge, cyclic CD has not previously been reported in association with primary ES. We describe a patient with cyclic CD associated with primary ES who was initially treated with ketoconazole and subsequently cured by transsphenoidal surgery.     

Cyclic Cushing's syndrome combined with cortisol suppressible, dexamethasone non-suppressible ACTH secretion: a new variant of Cushing's syndrome

A 55 year old woman with an unusual form of Cushing's disease was studied. During several periods (periods lasting up to 84 days) evidence of cortisol hypersecretion with cycles occurring every 6 days was found. Suppression of plasma cortisol through orally administered dexamethasone (up to 32 mg per day) could not be achieved either during periods of cyclic cortisol hypersecretion or during apparent remission with normal cortisol secretion. Marked suppression of plasma ACTH was measured in response to an iv infusion of 50 mg cortisol over a period of 55 min whereas a similar test with 2 mg dexamethasone (iv bolus) did not suppress ACTH secretion. Transsphenoidal exploration of the sella revealed a tumour surrounding the anterior pituitary. Examination of the pituitary showed a few tiny tumour structures embedded in normal tissue which could not be removed, when the tumour was resected selectively under preservation of normal appearing tissue. Post-operatively, clinical and chemical remission (normal response to 1 mg dexamethasone) was observed for about 4 months. Thereafter, cortisol hypersecretion occurred again necessitating bilateral adrenalectomy. Our results are compatible with the assumption that normal hypothalamic-pituitary-adrenal suppressibility with cortisol, but not with dexamethasone, was caused by the loss of feedback receptors for dexamethasone in the presence of cortisol receptors in the cells which secrete ACTH or CRF. The combination of cyclic hypercortisolism with dexamethasone non-suppressible Cushing's syndrome has not been reported before and thus represents a new variant of Cushing's syndrome.     

Cyclic Cushing's syndrome

Because glucocorticoids are necessary to sustain life and maintain homeostasis, adrenal disorders, if not detected in a timely fashion, can have serious consequences. Cyclic Cushing's syndrome is a disease characterized by rhythmic fluctuations in glucocorticoid production. In patients with this disorder, both clinical and biochemical spontaneous remissions may occur and therefore the activity of the hypothalamic-pituitary-adrenal axis between the cycles may be undisturbed. The clinical manifestation of cyclic Cushing's syndrome may be complex and varied, differing not only between patients but also in the same patient on a daily to monthly basis. The presence of cyclic Cushing's syndrome should always be considered in patients with a clinical presentation of hypercortisolism coexisting with normal glucocorticoid plasma levels and a paradoxical response to the dexamethasone test. We here present a detailed case report on a patient diagnosed with cyclic Cushing's syndrome. We report diagnostic and treatment strategies used in our patient and their impact on the course and outcome of the disease.     

Iatrogenic Cushing's syndrome due to dexamethasone nasal drops

Iatrogenic Cushing's syndrome presents all of the metabolic and immunologic abnormalities of the disease plus a suppressed hypothalamic-pituitary-adrenal axis. Most of the time the intake of steroids is quite evident, but occasionally it is not. This report presents such a patient who was using dexamethasone nasal drops for allergic rhinitis and in whom Cushing's syndrome developed. Five other similar cases were found in the literature. All except one were reported from outside the United States where these nasal steroid preparations are easily obtained over the counter. Absorption through the nasal mucosa and partly through the intestinal mucosa after a portion of the dose is swallowed is the mechanism of the systemic effect. Treatment consists in the discontinuation of the intranasal steroid preparation and tapering doses of prednisone to cover the secondary adrenal insufficiency until the axis recovers. Patients with Cushing's syndrome and suppressed levels of ACTH and cortisol should be asked about steroid intake, including nasal sprays and drops, particularly if they come from outside the United States. All of the cases reported occurred with dexamethasone. The newer intranasal steroids (beclomethasone and flunisolide) are not absorbed as readily through the nasal mucosa and are inactivated in the liver after gastrointestinal absorption. Therefore, it is not expected that they will produce Cushing's syndrome or adrenal suppression.     

"Normal suppression" to dexamethasone in Cushing's disease: an expression of decreased metabolic clearance for dexamethasone.

The adrenal cortical function of a patient with pituitary-dependent Cushing's syndrome exhibited normal responsiveness to conventional doses of dexamethasone (Dex) over several years of evaluation. "Periodic hormonogenesis" did not seem to explain the phenomenon. Plasma concentrations of Dex were measured to ascertain whether an abnormality in Dex metabolism might explain the apparent discrepancy in Dex responsiveness. Plasma levels of Dex after oral administration of the steroid were higher than normal, suggesting that decreased clearance of Dex accounts for the phenomenon of "normal suppression" in this patient with Cushing's syndrome.     

Vasopressin levels in Cushing's disease: inferior petrosal sinus assay, response to corticotrophin-releasing hormone and comparison with patients without Cushing's disease

BACKGROUND Higher vasopressin (AVP) levels have been found in the inferior petrosal sinus ipsilateral to the ACTH-secreting adenoma than in the contralateral one, suggesting a potential pathogenetic role of AVP in Cushing's disease. DESIGN In order to investigate AVP release, plasma ACTH and AVP concentrations were assayed in the inferior petrosal sinuses and in the peripheral blood before and after CRH stimulation. PATIENTS Twenty patients with Cushing's disease and 12 with other pituitary diseases were subjected to simultaneous and bilateral inferior petrosal sinus sampling for diagnostic purposes. Ten healthy sex and age-matched subjects served as control for peripheral AVP values. MEASUREMENTS Plasma ACTH concentrations were measured by RIA using commercial kits. Plasma AVP concentrations were assayed by RIA in acetone extracts of 1–2 ml plasma. RESULTS Plasma AVP levels in the inferior petrosal sinuses were significantly higher in Cushing's disease than in patients with other pituitary diseases (P<0.05) and in both groups AVP levels were higher in the inferior petrosal sinuses than in the peripheral blood (P<0.01). In Cushing's disease, ACTH, but not AVP levels, were higher in the inferior petrosal sinus ipsilateral to the adenoma than in the contralateral one (P<0.01). Seven patients showed a significant ACTH and AVP increase (greater than 50% of baseline) after CRH stimulation in the inferior petrosal sinus ipsilateral to the adenoma. Conversely, no change was found in AVP levels in the remaining 13 patients. When AVP values were analysed in relation to surgical cure, higher inferior petrosal sinus levels (P<0.05) were found in 6 patients with poor outcome: 4 of these patients had significantly decreased plasma AVP concentrations (by 32–43% of baseline) after CRH bolus. Peripheral AVP levels were similar in healthy subjects and patients with Cushing's disease whereas they were significantly reduced in patients with other pituitary diseases (P<0.002). CONCLUSIONS The results of this study show that patients with Cushing's disease and poor surgical outcome had the highest AVP levels in our series. CRH administration caused different effects on AVP levels: it increased them in 35% of patients whereas there was no response in the remaining patients. On the basis of these findings, it is hypothesized that AVP might be involved in the persistence of ACTH hypersecretion in a subset of patients poorly responsive to surgery.     

The paradoxical response to short-acting bronchodilator administration in patients with chronic obstructive pulmonary disease

BackgroundThere are a few studies about paradoxical bronchodilator response (BDR), which means a decrease in forced expiratory volume in 1 second (FEV₁) or forced vital capacity (FVC) after short-acting bronchodilator administration in patients with chronic obstructive pulmonary disease (COPD). We evaluated the effect of paradoxical BDR on the clinical outcomes of COPD patients in South Korea.MethodsWe analyzed the KOrea COpd Subgroup Study team (KOCOSS) cohort data in South Korea between January 2012 and December 2017. BDR was defined as at least a 12% and 200-mL reduction in FEV₁ or FVC after bronchodilator administration.ResultsA total of 1,991 patients were included in this study. A paradoxical BDR was noted in 57 (2.9%) patients and was independently associated with worse dyspnea and poor quality of life. High C-reactive protein (CRP) levels were associated with a paradoxical BDR (OR, 1.05; 95% CI, 1.01–1.09; P=0.003). However, paradoxical BDR was not associated with severe acute exacerbations. Pre-bronchodilator FEV₁ (L) showed a higher area under the curve (AUC) for predicting severe acute exacerbations than the post-bronchodilator FEV₁ (L) in the paradoxical BDR group (0.788 vs. 0.752).ConclusionA paradoxical reduction of FEV₁ or FVC after bronchodilator administration may be associated with chronic inflammation in the airway and independently associated with worse respiratory symptoms and poor quality of life.     

Cyclic Cushing's Syndrome: An Overview

Cyclic Cushing's syndrome (CS) involves rhythmic fluctuations in ACTH secretion resulting in a cyclic variation of adrenal steroid production. In the majority of cases, cyclic CS is caused by an ACTH-secreting pituitary adenoma, but it can also be due to ectopic ACTH production or an adrenal adenoma. This condition should be strongly suspected in patients with symptoms or signs of hypercortisolism but normal cortisol levels and paradoxical responses to the dexamethasone test, that may reflect an increasing or decreasing endogenous hormone activity. Dynamic tests are best interpreted if they are performed during a sustained period of hypercortisolism. Sometimes, it is necessary to confirm the diagnosis over lengthy periods of observation. Responses to treatment must be closely monitored, interpreted and evaluated with caution because of the potential variations in steroidogenesis. An original case report of a cyclic Cushing's syndrome is presented in this review.     

Cyclic Cushing's syndrome: an overview

Cyclic Cushing's syndrome (CS) is a disorder in which glucocorticoid levels are alternately normal and high, the latter occurring in episodes that can last from a few days to several months. It is more common in children than in adults. Cyclic CS may be either of the two different forms of CS (ACTH-dependent or -independent CS). Clinically, it may present with one or many symptoms, depending on the duration of disease activity and the timing of the fluctuations. A serotoninergic influence, cyclic changes in central dopaminergic tone, spontaneous episodic hemorrhage in the tumor, and the action of inflammatory cytokines with antitumor properties are some of the mechanisms suggested to explain the physiopathology of this phenomenon but the exact mechanism remains to be clarified. The cyclic pattern of hypercortisolism can delay the final diagnosis of CS and make it difficult to interpret the results of dynamic tests. Patients may have paradoxical responses to dexamethasone that can reflect increasing or decreasing levels of endogenous activity. Hormone assessments have to be repeated periodically when a diagnosis of CS is suspected. The cyclic pattern can also interfere with medical treatment because patients may show unexpected clinical and biochemical signs of hypocortisolism when cortisol secretion cyclically returns to normal, so an accurate follow-up is mandatory in these patients.