Pituitary Hormone Abnormalities Research Articles

Multiple pituitary hormone abnormalities, fever, behavioral problems, seizures and apnoic spells in a 6-year old girl

A 6-year old girl was examined having two years previously presented a transient Cushing's syndrome, followed by recurrent hyponatremia, attributed to inappropriate ADH secretion (SIADH). The brain MRI showed no abnormalities on repeated examinations, except for a suggestion of empty sella syndrome. During the past two years she also presented recurrent episodes of a prolonged febrile illness of unknown origin. All investigations related to infectious, autoimmune neoplastic diseases, histiocytosis-X or neurosarcoidosis were negative and the fever was characterized as central. The patient also presented episodes of tonic-clonic seizures, myoclonias and behavioral problems (alternating states of irritability, sleepiness and apathy, optic and hearing illusions and phobias) with or without hyponatremia. Her cerebrospinal fluid (CSF) examination was not indicative of encephalitis and the encephalogram (EEG) showed only slowing of background activity. At the age of 4.75 years she, started to have recurrent episodes of hypopnoea/apnoea with severe desaturation and hypercapnia, occasionally requiring intubation and ventilation. She also developed unilateral miosis corneal ulceration and bilateral ptosis (oculo-sympathetic paresis). Repeat brain MRI and CT scans of the mediastinum excluded organic causes of apnoeas and of oculo-sympathetic paresis, such as neuroblastoma or lymphoma. Furthermore, on a 24 hour electrocardiogram recording, using power spectral analysis, significantly reduced heart rate variability was observed, by comparison with age-specific normal ranges. Thus the apnoeas, ptosis, miosis and temperature instability were attributed to autonomic dysfunction. During the same period, the patient presented significant growth retardation and growth hormone (GH) deficiency was confirmed during two provocative tests (peak GH levels: 3.1 and 2.9 ng/ml (normal>10). Moreover, thyrotropin (TSH) deficiency and persistent hyperprolactinemia were detected. She was started on hGH and thyroxine. She was also put on fluid restriction and increased sodium intake for her SIADH. She was advised to use O2 administration by mask in case of apnoeas. The child died at age 6 6/12 years as a result of apnoea during sleep. Multiple pituitary hormonal abnormalities, together with symptoms of autonomic neuropathy (apnoeas, ptosis, miosis, tachycardia, temperature instability) and encephalopathy (seizures, myoclonias and behavioral problems) developed in a 4-year old girl. The suggested diagnoses were: 1. Neurometabolic disorder, 2. Mitochondrial disorder, 3. Post infectious autoimmune process.

Pituitary Tumor Apoplexy: Pathophysiology, Clinical Manifestations, and Management

Pituitary tumor apoplexy represents a rare clinical syndrome caused by hemorrhagic infarction of an existing, often previously unrecognized, large adenoma. We present our approach and experience in the field, and we provide a summary of pertinent published literature addressing diagnosis, management, and pathophysiology of the clinical manifestations of pituitary tumor apoplexy. Although many precipitating factors are known, most episodes occur spontaneously and present clinically with relatively sudden onset of severe headache, visual field defects, and ophthalmoplegia. Either computed tomography (nonenhanced and enhanced) or magnetic resonance imaging in a symptomatic patient can define pertinent anatomical changes and aid in establishing diagnosis. Immediate treatment with corticosteroids is necessary. Patients with the mild form of the syndrome respond quickly to steroids and can be managed conservatively with continued glucocorticoid therapy. Most patients with persistent neural deficits require urgent transsphenoidal decompression. Unless surgery is delayed, results of transsphenoidal decompression are usually very good, and improvements in neurological symptoms and endocrine function are noted within hours to days of the procedure. Patients need to be closely followed up after the episode because a large number continue to have residual tumor requiring additional therapy, or they have pituitary hormone abnormalities that need treatment. Close interaction between neurosurgeons and endocrinologists in the management of patients with pituitary tumor apoplexy is essential for optimal outcome.

Abnormal growth hormone and cortisol, but not thyroid-stimulating hormone, responses to an intravenous glucose tolerance test in normal-weight, bulimic women

Abnormal growth hormone (GH) and adrenocorticotropic hormone (ACTH)/cortisol secretory patterns in response to a glucose load have been observed in underweight anorectic women. The present study was performed in an attempt to establish whether changes in the hypothalamic/pituitary sensitivity to hyperglycemia occur in bulimia in the absence of weight disturbance. Therefore, serum GH, plasma cortisol, and plasma insulin concentrations were measured in eight women with normal weight bulimia and in eight normal women during an intravenous glucose (0.33 g/kg as an iv bolus) tolerance test (IGTT). In addition, since abnormal pituitary hormone responses to a glucose load might reflect alterations in somatostatin (SRIH) release, TSH secretion also was measured, in view of its sensitivity to SRIH inhibition. Both GH and cortisol levels progressively and significantly declined during IGTT in the normal subjects. In the bulimic women, cortisol levels remained unchanged, whereas GH concentrations rose significantly after glucose injection. Plasma cortisol and serum GH levels were significantly higher in the bulimic than in the control subjects. No significant differences between groups were observed in hyperglycemia-induced insulin increments or in TSH decrements. These data indicate that an altered sensitivity to hyperglycemia affects the hypothalamic/pituitary centers controlling the secretion of the counterregulatory hormones GH and ACTH/cortisol in bulimia nervosa. The lack of a simultaneous change in the TSH secretory pattern argues against a possible involvement of SRIH in the pathophysiology of this disorder.

Growth hormone response to L-Dopa and clonidine in autistic children

Studies have shown abnormal pituitary hormone responses to neuroendocrine agonists in autistic subjects. Two probes (clonidine and L-Dopa) were used to investigate neuroendocrine responses through changes in growth hormone levels. Seven medication-free autistic subjects (ages 6.6 to 19.1) were evaluated and compared to 14 normal controls. Growth hormone was collected at 30-min intervals during the entire study. Clonidine was administered first (dose: 0.15 mgm2), and samples were collected for 180 min. L-Dopa was then administered (dose: 250 mg for subjects less than 70 lb and 500 mg for subjects greater than 70 lb), and samples were collected for 120 min. There was no difference in the amplitude of the clonidine or L-Dopa peak growth hormone responses in the control versus the autistic subjects. In the autistic subjects, the L-Dopa-stimulated growth hormone peak was delayed and the clonidine growth hormone peak was premature. A statistical difference with the control subjects was found when consideration was given to both the premature response of growth hormone to clonidine and the delayed response to L-Dopa (p = .01, Fisher's Exact Test). These findings suggest possible abnormalities of both dopaminergic and noradrenergic neurotransmission in subjects with autism.

ACUTE AND CHRONIC PITUITARY FAILURE RESEMBLING SHEEHAN'S SYNDROME FOLLOWING BITES BY RUSSELL'S VIPER IN BURMA

Pituitary function was investigated in 9 patients in shock after Russell's viper bites and in 24 individuals who had been severely envenomed 2 weeks to 24 years previously. 3 out of 9 patients had hypoglycaemia and inappropriately low serum cortisol, plasma growth hormone, and plasma prolactin concentrations. 4 who died had pituitary haemorrhage and 1 had adrenal haemorrhage as well. Of the 24 who had apparently recovered from bites, 7 had clinical features of hypopituitarism and no response in plasma growth hormone or prolactin concentrations to symptom-producing insulin-induced hypoglycaemia. 4 of these 7 had a sluggish serum cortisol response to 'Synacthen Depot' and 5 had an abnormal cortisol response to hypoglycaemia. 4 men with symptoms who were tested had low serum testosterone concentrations; serum thyroxine was also low in these men but not in 2 women with menstrual disturbances and impaired insulin responses. Of the 17 individuals without clinical evidence of endocrine disease, 4 had pituitary hormonal abnormalities. Russell's viper envenoming may thus produce a disorder resembling Sheehan's syndrome.

Abnormal conjugated dopamine levels in patients with normoprolactinaemic amenorrhoea and in insulin-dependent diabetic patients.

We determined the circulating dopamine levels in 17 patients with insulin-dependent diabetes mellitus (IDDM), of whom eight had amenorrhoea (DM-AM) and nine were normally menstruating (DM). Seven non-diabetic women with normoprolactinaemic, normogonadotrophic secondary amenorrhoea (AM) and nine normally menstruating women (controls) were studied. In all subjects basal blood concentrations of free dopamine (f-DA), conjugated dopamine (c-DA), epinephrine (E), norepinephrine (NE), prolactin (PRL), luteinizing hormone (LH), thyroid-stimulating hormone (TSH) and oestradiol-17 beta were determined and all subjects, except for three AM patients, had a Metoclopramide test performed for measurements of f-DA, c-DA, PRL, LH and TSH. Plasma c-DA was significantly (p less than 0.05) increased in patients with amenorrhoea compared to the respective control groups. In diabetic patients c-DA levels were significantly (p less than 0.05) lower compared to controls. The ratio between basal f-DA and c-DA concentrations was significantly (p less than 0.01) higher in diabetic patients compared with non-diabetic patients. After Metoclopramide stimulation DM-AM patients showed a significant (p less than 0.05) rise in c-DA, whereas this was not seen in other groups. DM-AM patients had significantly (p less than 0.05) lower basal PRL and LH levels than DM patients and controls. In addition DM-AM patients had a significantly (p less than 0.05) lower PRL response to Metoclopramide compared with DM patients. There were no significant correlations between catecholamines and basal as well as Metoclopramide stimulated pituitary hormones. This study suggests that the abnormal pituitary hormone secretion in patients with amenorrhoea may in part be caused by an increased dopaminergic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

3 - Current approaches to hypothalamic-pituitary radiology

Currently computed tomography (CT) is the primary imaging modality for pituitary and hypothalamic lesions, although it is probable that NMR will supersede it. The range of size of the normal pituitary is considerable, with relatively larger glands occurring in adolescence and females of childbearing age. Asymptomatic microadenomas and cysts are not infrequent so that small low-density lesions in a gland on the borderline of enlargement can only be assessed in relation to clinical presentation. Patients presenting with clinical or biochemical evidence of abnormal pituitary hormone secretion or with an enlarged sella but without evidence of any neurological abnormality are likely to have either a small pituitary tumour or an empty sella and are investigated by thin section high resolution CT to produce coronal and sagittal images. Visual defects, paralysis of ocular muscles or hypothalamic disturbances, in the absence of clinical evidence of hypersecretion of pituitary hormones, may be due to a variety of pathologies. These cases are elucidated by plain plus contrast-enhanced CT, supplemented as necessary by angiography and computed cysternography after injection of non-ionic contrast media. Hypothalamic disturbances may occasionally complicate cerebral malformations which are also elucidated by cranial CT.