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The assessment of the hypothalamo-pituitary-adrenal axis in pituitary disease: are there short cuts?Journal of Endocrinological... 2003The main task of the hypothalamo-pituitary-adrenal (HPA) axis is to enable sufficient cortisol release under regular and stressful situations. Therefore, to prove its... (Review)
Review
The main task of the hypothalamo-pituitary-adrenal (HPA) axis is to enable sufficient cortisol release under regular and stressful situations. Therefore, to prove its being intact in pituitary disease, stimulation tests are usually needed. Cortisol level has to be shown to exceed a threshold level, which has to be defined on normal subjects in each lab, as results may differ greatly. Insulin tolerance test (ITT) is considered the "gold standard". Hypoglycemia induces a severe stress, which stimulates the HPA axis maximally. However, for regularly accepted cut-off points (18-20 microg/dl, 500-550 nmol/l), false positive results are documented, even in normal volunteers, and reproducibility is far from perfect. The metyrapone test, by blocking cortisol production, stimulates ACTH release to overcome the blockade. In this test 11-DOC levels are usually measured, and a cut-off point of 7.0 microg/dl (200 nmol/l) used. Measuring ACTH and/or cortisol + 11-DOC levels may improve the test, both in reasoning and reliability. The CRH test yields unsatisfactory results, and its use is usually saved for differential diagnosis of hypercortisolism. The ACTH test is the easiest to perform, and usually used as a screening test. Abnormal responses should be considered diagnostic, while normal responses, especially in newly onset or recent pituitary disease, should be followed by either ITT or metyrapone test. Most studies show superiority of the 1.0 microg (so called "low dose") ACTH test over the high dose (250 microg) test. The physiologic dose test should replace the pharmacologic dose test whenever ACTH test is considered. In every test there are limitations and pitfalls. Knowing them, and using best clinical judgment, will reduce and minimalize mistakes.
Topics: Adrenocorticotropic Hormone; Corticotropin-Releasing Hormone; Diagnostic Techniques, Endocrine; Enzyme Inhibitors; Feedback, Physiological; Glucose Tolerance Test; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Metyrapone; Pituitary Diseases; Pituitary-Adrenal System
PubMed: 14604063
DOI: No ID Found -
Psychotherapy and Psychosomatics 1998Chronic medical illness not only affects the patient but the entire family. The family system undergoes a tremendous change in focus during the acute illness, with... (Review)
Review
Chronic medical illness not only affects the patient but the entire family. The family system undergoes a tremendous change in focus during the acute illness, with members marshaling their resources to help the ill member. This inward focus is costly, producing profound stress. Often, family communication styles change to protect the family system and prior functioning. When the stress of caring for an ill member becomes chronic, as is seen in pituitary disease, the initially adaptive changes in family functioning may become problematic even in those families with previously healthy coping. Those families with previously less healthy functioning become even more dysfunctional. Each family identifies a caregiver for their ill member. This caregiver also experiences significant stress related to caregiving demands. Caregiver adaptation to the stress depends on how the stress is perceived, as well as the caregiver's coping patterns and availability of and satisfaction with social support. These elements comprise a stress process model of caregiving, which has been well-validated in dementia caregiving research. Although the majority of research has focused on dementia and cancer caregiving, identified issues have applicability to caregiving and family issues related to pituitary disease. This report will review: (1) the field of caregiving research, focusing on a stress process model; (2) those issues identified in prior caregiving research which have applicability in caregiving for patients with pituitary disease; (3) stresses on the family system; (4) assessment of family functioning, and (5) interventions for caregivers and areas for future research.
Topics: Caregivers; Family Health; Humans; Pituitary Diseases; Research; Stress, Psychological
PubMed: 9667066
DOI: 10.1159/000012279 -
The Veterinary Record Mar 2023
Topics: Dogs; Animals; Pituitary ACTH Hypersecretion; Pituitary Diseases; Printing, Three-Dimensional; Dog Diseases
PubMed: 36866870
DOI: 10.1002/vetr.2801 -
Ageing Research Reviews May 2007Parkinson's disease (PD) is a leading cause of neurologic disability in the aged population. Remarkable progress has been made in the past decade to understand the... (Review)
Review
Parkinson's disease (PD) is a leading cause of neurologic disability in the aged population. Remarkable progress has been made in the past decade to understand the cellular and molecular events that occur in PD. However attempts to unravel the early, initiating factors in the pathogenesis of dopaminergic neurodegeneration and PD have been limited by the lack of a suitable animal model. Models in which there has been genetic or environmental manipulation are not of use in determining the natural cause of a disease. While a large scale prospective human study would be ideal, the relatively low prevalence of PD makes this approach economically and logistically infeasible. Equine pituitary pars intermedia dysfunction (PPID) is a spontaneous, progressive neuroendocrine disease that commonly affects aged horses and ponies. PPID results from neurodegeneration of the dopaminergic periventricular neurons that innervate the intermediate lobe of the pituitary. PPID is 10-20 times more prevalent than PD and may be readily diagnosed without a need for advanced imaging technology. Although the diseases are anatomically distinct, recent evidence suggests the pathogenesis of dopaminergic neuronal damage in PPID may have significant similarities to that of PD. In this review, the similarities and differences in the pathology of neurodegeneration in PPID and PD are compared. The potential utility of the horse as a model of spontaneous dopaminergic neurodegeneration is discussed.
Topics: Animals; Disease Models, Animal; Horse Diseases; Horses; Humans; Parkinson Disease; Pituitary Diseases; Pituitary Gland, Intermediate
PubMed: 17374512
DOI: 10.1016/j.arr.2007.02.001 -
Handbook of Clinical Neurology 2016Significant advances in pituitary imaging have taken place in the past several decades, including the introduction of magnetic resonance imaging (MRI). This imaging... (Review)
Review
Significant advances in pituitary imaging have taken place in the past several decades, including the introduction of magnetic resonance imaging (MRI). This imaging modality has vastly improved our ability to detect and characterize sellar masses and more accurately characterize the extent and spread of lesions in and around the sella. Intraoperative MRI may help improve the completeness of resection of sellar masses. Other imaging modalities, including magnetic resonance angiography, computed tomography (CT), and CT angiography, have an important role in specific cases. Interventional methods, including bilateral inferior petrosal sinus sampling, may establish the pituitary origin of corticotropin (ACTH) excess in patients with ACTH-dependent Cushing's syndrome. Pituitary imaging should be obtained in patients with pituitary hormone excess, hypopituitarism, or mass effect in the sella. Despite rapid advances in pituitary imaging, there are several diagnostic challenges remaining. Future research may help improve the radiographic detection of small sellar lesions, such as ACTH-secreting adenomas causing Cushing's disease, accurately characterize the type and extent of sellar pathologies, and provide prognostic information regarding their growth potential.
Topics: Adrenocorticotropic Hormone; Humans; Neuroimaging; Pituitary Diseases; Pituitary Gland
PubMed: 27430447
DOI: 10.1016/B978-0-444-53486-6.00044-2 -
Veterinary Journal (London, England :... May 2018Pituitary pars intermedia dysfunction (PPID) is caused by an age-related degenerative disease of dopaminergic neurones. Despite its importance in equine practice,... (Review)
Review
Pituitary pars intermedia dysfunction (PPID) is caused by an age-related degenerative disease of dopaminergic neurones. Despite its importance in equine practice, available information regarding its epidemiology is limited. This systematic review aimed to assess published literature to evaluate available evidence regarding the clinical presentation, prevalence and risk factors for PPID in horses and ponies. Electronic database searches were undertaken using a range of terms, and English language publications published prior to August 2016 were included. Both authors independently reviewed screened papers for inclusion, extracted data, and assessed the quality of reporting using predefined criteria. Data were extracted using modified critically appraised topic data collection forms. Meta-analysis was not undertaken due to marked between-study variations. Following removal of duplicate records, of 358 published papers yielded by the search, 97 abstracts were screened for eligibility and 29 publications meeting inclusion criteria were included in the review. Most studies reviewed were case series or cross-sectional studies, with considerable variation in study populations and PPID case definition. Hypertrichosis and/or other hair coat abnormalities, laminitis and epaxial muscle wastage or muscle atrophy are the most frequently reported clinical signs, with prevalence of these signs increasing with increasing horse age. The most robust prevalence estimates for PPID were 21.2% in horses and ponies aged ≥15 years and 2.9% amongst the general equine population. Findings regarding breed and sex predispositions were equivocal and only increasing age has been identified as a significant risk factor for PPID.
Topics: Aging; Animals; Female; Horse Diseases; Horses; Male; Neurodegenerative Diseases; Pituitary Diseases; Pituitary Gland, Intermediate; Risk Factors
PubMed: 29704935
DOI: 10.1016/j.tvjl.2018.03.002 -
Current Opinion in Endocrinology,... Aug 2016Patients with pituitary diseases have decreased quality of life. Sleep disorders are prevalent among patients with pituitary diseases and contribute to decreased quality... (Review)
Review
PURPOSE OF REVIEW
Patients with pituitary diseases have decreased quality of life. Sleep disorders are prevalent among patients with pituitary diseases and contribute to decreased quality of life.
RECENT FINDINGS
Patients previously treated for compression of the optic chiasm by surgery, and in some cases postoperative radiotherapy, suffer from sleep disorders. These are characterized by decreased sleep quality, delayed onset of sleep, and daytime sleepiness. Circumstantial evidence suggests that this may be caused by hypothalamic dysfunction. A challenging speculation is that previous compression of the optic chiasm compromised the function of the retinohypothalamic tract. Through this tract the eyes convey information on day-night cycles to the hypothalamic nuclei. Patients with acromegaly, even despite biochemical control, suffer frequently from obstructive sleep apnea. Patients with Cushing's disease suffer from fragmented sleep, sleep apnea, and snoring. Prolactinomas do not seem to affect sleep characteristics. The association between appropriately substituted pituitary insufficiency and sleep disorders is less clear. The effects of recombinant human growth hormone on sleep characteristics in adults are inconsistent.
SUMMARY
Pituitary disorders are associated with different sleep disorders. Different studies point to irreversible changes in sleep-wake rhythmicity in patients treated previously for pituitary tumors with chiasm compression. VIDEO ABSTRACT.
Topics: Humans; Optic Chiasm; Pituitary Diseases; Sleep Wake Disorders
PubMed: 27254266
DOI: 10.1097/MED.0000000000000265 -
Neurology India 2019The eye is a vital sense organ and plays a vital role in conveying the underlying physical and mental state of wellbeing of an individual. A comprehensive examination of... (Review)
Review
The eye is a vital sense organ and plays a vital role in conveying the underlying physical and mental state of wellbeing of an individual. A comprehensive examination of the eye is often required in patients presenting with systemic complaints. Many endocrine disorders have characteristic manifestations pertaining to the eye, the classical being the exophthalmos in thyrotoxicosis. However, a cursory eye evaluation may lead to the identification of early features that can help in the diagnosis of other endocrine disorders. This is more common in cases of pituitary mass lesions, who often present with the functional hormonal alterations rather than the visual symptoms. The definitive therapy during the late stages of the disease leads to persisting visual disabilities and affects the quality of life. Hence, the endocrinologists and ophthalmologists need to be aware of various ophthalmic features in the pituitary disorders. In this review, we highlight the eye signs in pituitary disorders, along with a brief description of uncommon ocular-pituitary syndromes.
Topics: Eye Diseases; Humans; Pituitary Diseases; Vision Disorders
PubMed: 31512618
DOI: 10.4103/0028-3886.266265 -
Minerva Endocrinologica Sep 2016
Topics: Adenoma; Humans; Pituitary Diseases; Pituitary Neoplasms
PubMed: 27381738
DOI: No ID Found -
Clinics in Endocrinology and Metabolism Nov 1983Success in the treatment of pituitary tumours depends on their size and invasiveness so that early detection is imperative. Immediate cure of microadenomas is assured by... (Review)
Review
Success in the treatment of pituitary tumours depends on their size and invasiveness so that early detection is imperative. Immediate cure of microadenomas is assured by trans-sphenoidal microsurgery although longterm results are not yet established. Complete removal of large tumours is less likely and radiotherapy is advised if there is evidence of residual tumour activity. External irradiation is indicated in the treatment of radiosensitive germinomas. Drugs can control symptoms before surgery or while awaiting the effects of radiotherapy but may be the treatment of choice for large prolactinomas. Bromocriptine or other dopamine agonists not only inhibit prolactin secretion but also limit tumour size, but it is not known if they are effective indefinitely. Dynamic tests of pituitary function should precede hormone replacement therapy and careful supervision with monitoring of plasma hormone levels accompany long-term treatment.
Topics: Acromegaly; Adenoma; Cushing Syndrome; Feedback; Female; Gonadal Steroid Hormones; Growth Hormone; Humans; Hyperthyroidism; Male; Nelson Syndrome; Pituitary Diseases; Pituitary Neoplasms; Prolactin
PubMed: 6368056
DOI: 10.1016/s0300-595x(83)80064-4