The past 45 yr' experience with Cushing's syndrome (CS) has led to the awareness of its complex nature and, by the same token, brought about an increase in the diagnostic and therapeutic dilemmas. We carried out a retrospective multicentre study on the diagnostic work-up and treatment in 426 patients with CS, subdivided as follows: 288 with Cushing's disease (CD), 80 with an adrenal adenoma, 24 with an adrenal carcinoma, 25 with ectopic ACTH and/or CRH secretion, and 9 with ACTH-independent nodular adrenal hyperplasia. Normal urinary free cortisol (UFC) values among multiple collections were recorded in about 10% of patients with CS. In 28% of patients with ACTH-independent CS, basal ACTH concentrations were within the normal range but did not respond to CRH stimulation. Measurement of ACTH levels by immunoradiometric assay, rather than by RIA, offered a greater chance of recognizing patients with ACTH-independent CS or ectopic secretion. A 50% increase in ACTH or cortisol levels after CRH yielded a diagnostic accuracy of 86% and 61%, respectively, in the differential diagnosis of ACTH-dependent CS. An 80% decrease in cortisol levels after 8 mg dexamethasone overnight, or in UFC values after the classical 2-day administration, excluded an ectopic secretion but carried a low negative predictive value given the high number of nonsuppressors among patients with CD. Pituitary imaging identified an adenoma in 61% of patients with CD. At inferior petrosal sinus sampling, an ACTH centre: periphery gradient after CRH less than 3, correctly classified all patients with ectopic secretion but misdiagnosed 15% of 76 patients with CD. Transsphenoidal pituitary surgery, the standard therapy for CD, resulted in complete remission (appearance of clinical signs of adrenal insufficiency associated with low/normal UFC excretion and, when available, low/normal morning plasma ACTH and cortisol levels) in 69% of patients. The overall relapse rate after pituitary surgery was 17%. The probability of relapse-free survival, as assessed by Kaplan-Meier analysis, was 95% at 12 months, 84% at 2 yr, and 80% at 3 yr. Risk of relapse was significantly correlated with postoperative baseline plasma ACTH and cortisol peak after CRH. No relapses were observed among patients who did not respond to CRH. Other therapeutic approaches for CD, such as pituitary irradiation and medical therapy, resulted in normalization of cortisol secretion in about half of treated cases. In summary, an accurate selection of the available diagnostic tools leads to the correct diagnosis in the majority of patients with CS. The therapeutic options for CD, adrenal carcinoma, and ectopic secretion are, as yet, not fully satisfactory. The high incidence of relapse after pituitary surgery calls for a prolonged follow-up.
Timing is extremely important for movement, and understanding the neurobiological basis of rhythm perception and reproduction can be helpful in addressing motor recovery after brain lesions. In this quest, the science of music might provide interesting hints for better understanding the brain timing mechanism. The report focuses on the neurobiological substrate of sensorimotor transformation of time data, highlighting the power of auditory rhythmic stimuli in guiding motor acts. The cerebellar role of timing is addressed in subjects with cerebellar damage; subsequently, cerebellar timing processing is highlighted through an fMRI study of professional musicians. The two approaches converge to demonstrate that different levels of time processing exist, one conscious and one not, and to support the idea that timing is a distributed function. The hypothesis that unconscious motor responses to auditory rhythmic stimuli can be relevant in guiding motor recovery and modulating music perception is advanced and discussed.
Cushing's syndrome is associated with an increased risk for abnormalities of cardiac mass, which ameliorates, but does not fully disappear after remission. Systolic and diastolic functions are largely within the normal range in these patients.
Acromegalic patients frequently display an abnormally prolonged QT interval, a known risk factor for potentially fatal arrhythmias. Treatment of these patients with SSA is able to improve and even normalize this alteration, probably contributing to the beneficial effects of these drugs on cardiac rhythm in this endocrine disorder. The inclusion of octreotide in the list of drugs that may increase QTc should be reconsidered as regards its indication in acromegaly.
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