Dual facets of hyponatraemia and arginine vasopressin in patients with ACTH deficiency

Rehabilitation of anterior pituitary dysfunction combined with extrapontine myelinolysis: A case report

BACKGROUND

Extramedullary myelinolysis is a rare demyelinating disease, often caused by rapid increases in serum sodium concentration in patients with hyponatremia. Clinical manifestations are neuropsychiatric symptoms, limb weakness, and dysarthria. Because of its poor prognosis and high disability rate, it poses a huge burden on the global economy, societies, and families. This article reports rehabilitation in a patient with pituitary dysfunction combined with extramedullary myelinolysis.

CASE SUMMARY

A 27-year-old Chinese man developed anorexia, vomiting, and limb weakness and was diagnosed with pituitary insufficiency. He had low serum sodium, slow movement, muscle weakness, and muscle tone abnormalities after sodium supplementation, involuntary limb shaking, ataxia, and dysarthria. According to the symptoms and signs and imaging reports, he was diagnosed with extramedullary myelinolysis. After treatment with hormone therapy and neurotrophic drugs, motor and speech function did not improve, so he was treated in the rehabilitation department for 4 wk. The patient's physical status was improved substantially during his stay at the rehabilitation department.

CONCLUSION

Patients with extramedullary myelinolysis who actively participate in rehabilitation intervention can significantly improve their activities of daily living.

Impact of etiology, age and gender on onset and severity of hyponatremia in patients with hypopituitarism: retrospective analysis in a specialised endocrine unit

BACKGROUND

Hyponatremia can unmask hypopituitarism and secondary adrenal insufficiency. This is important, since the need to screen for steroid deficiency, in patients with hyponatremia is often neglected.

PATIENTS AND METHODS

In a retrospective study, twenty-five patients (13f/12m, age 58.9 ± 18.6 years) with hyponatremia (119.7 ± 10.5 mmol/L) were identified among 260 in-patients treated for hypopituitarism in our specialized endocrine unit, over the last decade. We analyzed clinical characteristics, etiology, and severity of hypopituitarism in patients who presented with hyponatremia.

RESULTS

Hyponatremia was recorded in 9.6% of our patients with hypopituitarism. In 80.7% it was the key to diagnosis of hypopituitarism. All patients with hyponatremia were steroid deficient with complete hypopituitarism compared to 75% (steroid deficient) and 60% (complete hypopituitarism) of the patients in the cohort. The most common etiology of hypopituitarism was non-functioning pituitary macro adenoma (NFPA) (n = 128, 49.2%). Patients with hyponatremia were divided into two groups, based on the etiology of hypopituitarism: Group 1. with NFPA n = 15 (5F/10M), mean age 71.47 ± 4.8 years, who were significantly older compared to patients with hyponatremia from other rare causes of hypopituitarism in Group 2. n = 10 (8F/2M), mean age 40.2 ± 15.3 years (p < 0.01), such as: congenital hypopituitarism(n = 2), Sheehan's syndrome (n = 2), intracranial aneurysm (n = 2), lymphocytic hypophysitis (n = 1), traumatic brain injury (n = 1), surgery and radiotherapy for astrocytoma (n = 1), pituitary metastasis from bronchial carcinoma (n = 1). Hyponatremia was more severe in Group 2. compared to Group 1. (113.5 ± 10.9 mmol/L vs. 124.3 ± 8.1 mmol/L, p < 0.01). Older age (p = 0.0001) and number of endocrine deficiencies (p < 0.05) were identified as predictive factors for hyponatremia by multivariate analysis in patients with hypopituitarism.

CONCLUSION

Hyponatremia is an important presenting feature of pituitary disease and a strong indicator of life-threatening steroid deficiency. Old age and severity of hypopituitarism are major risk factors for hyponatremia. In older patients NFPA is the most common etiology, while other rare causes of hypopituitarism are more prevalent in younger patients with hyponatremia.

The contribution of undiagnosed adrenal insufficiency to euvolaemic hyponatraemia: results of a large prospective single-centre study

OBJECTIVE

The syndrome of inappropriate antidiuresis (SIAD) is the commonest cause of hyponatraemia. Data on SIAD are mainly derived from retrospective studies, often with poor ascertainment of the minimum criteria for the correct diagnosis. Reliable data on the incidence of adrenal failure in SIAD are therefore unavailable. The aim of the study was to describe the aetiology of SIAD and in particular to define the prevalence of undiagnosed adrenal insufficiency.

DESIGN

Prospective, single centre, noninterventional, observational study of patients admitted to Beaumont Hospital with euvolaemic hyponatraemia (plasma sodium ≤ 130 mmol/l) between January 1st and October 1st 2015.

PATIENTS

A total of 1323 admissions with hyponatraemia were prospectively evaluated; 576 had euvolaemic hyponatraemia, with 573 (43·4%) initially classified as SIAD.

MAIN OUTCOME MEASURES

(i) Aetiology of SIAD, defined by diagnostic criteria; (ii) Incidence of adrenal insufficiency.

RESULTS

Central nervous system diseases were the commonest cause of SIAD (n = 148, 26%) followed by pulmonary diseases (n = 111, 19%), malignancy (n = 105, 18%) and drugs (n = 47, 8%). A total of 22 patients (3·8%), initially diagnosed as SIAD, were reclassified as secondary adrenal insufficiency on the basis of cortisol measurements and clinical presentation; 9/22 cases had undiagnosed hypopituitarism; 13/22 patients had secondary adrenal insufficiency due to exogenous steroid administration.

CONCLUSIONS

In a large, prospective and well-defined cohort of euvolaemic hyponatraemia, undiagnosed secondary adrenal insufficiency co-occurred in 3·8% of cases initially diagnosed as SIAD. Undiagnosed pituitary disease was responsible for 1·5% of cases presenting as euvolaemic hyponatraemia.

Clinical review: practical approach to hyponatraemia and hypernatraemia in critically ill patients

Disturbances in sodium concentration are common in the critically ill patient and associated with increased mortality. The key principle in treatment and prevention is that plasma [Na+] (P-[Na+]) is determined by external water and cation balances. P-[Na+] determines plasma tonicity. An important exception is hyperglycaemia, where P-[Na+] may be reduced despite plasma hypertonicity. The patient is first treated to secure airway, breathing and circulation to diminish secondary organ damage. Symptoms are critical when handling a patient with hyponatraemia. Severe symptoms are treated with 2 ml/kg 3% NaCl bolus infusions irrespective of the supposed duration of hyponatraemia. The goal is to reduce cerebral symptoms. The bolus therapy ensures an immediate and controllable rise in P-[Na+]. A maximum of three boluses are given (increases P-[Na+] about 6 mmol/l). In all patients with hyponatraemia, correction above 10 mmol/l/day must be avoided to reduce the risk of osmotic demyelination. Practical measures for handling a rapid rise in P-[Na+] are discussed. The risk of overcorrection is associated with the mechanisms that cause hyponatraemia. Traditional classifications according to volume status are notoriously difficult to handle in clinical practice. Moreover, multiple combined mechanisms are common. More than one mechanism must therefore be considered for safe and lasting correction. Hypernatraemia is less common than hyponatraemia, but implies that the patient is more ill and has a worse prognosis. A practical approach includes treatment of the underlying diseases and restoration of the distorted water and salt balances. Multiple combined mechanisms are common and must be searched for. Importantly, hypernatraemia is not only a matter of water deficit, and treatment of the critically ill patient with an accumulated fluid balance of 20 litres and corresponding weight gain should not comprise more water, but measures to invoke a negative cation balance. Reduction of hypernatraemia/hypertonicity is critical, but should not exceed 12 mmol/l/day in order to reduce the risk of rebounding brain oedema.

Endocrine disorders: causes of hyponatremia not to neglect

Hyponatremia is a common electrolyte abnormality with the potential for significant morbidity and mortality. Endocrine disorders, including adrenal deficiency and hypothyroidism, are uncommon causes of hyponatremia. Primary adrenal insufficiency (i.e. Addison's disease) may well be recognized by clear hall-marks of the disease, such as pigmentation, salt craving, hypotension, and concomitant hyperkalemia. Addison's disease is an important diagnosis not to be missed since the consequences can be grave. On the other hand, hypothyroidism and secondary adrenocortical insufficiency originating from diseases of the hypothalamus and/or pituitary (hypopituitarism) require a high index of suspicion, because the clinical signs can be quite subtle. This review focuses on clinical and pathophysiological aspects of hyponatremia due to endocrine disorders.

Isolated adrenocorticotropin deficiency in a child with Kabuki syndrome

A 6 year-old Chinese boy with Kabuki syndrome presented with hypoglycemic seizure. He was diagnosed to have isolated adrenocorticotropin deficiency. To our knowledge, this is the first case of Kabuki syndrome with isolated adrenocorticotropin deficiency in the literature.

Symptomatic hyponatremia as a presenting sign of hypothalamic-pituitary disease: a syndrome of inappropriate secretion of antidiuretic hormone (SIADH)-like glucocorticosteroid responsive condition

Hyponatremia associated with high urine osmolality is usually caused by inappropriate secretion of antidiuretic hormone. However, secondary hypoadrenalism is also accompanied by hyponatremia and with features indistinguishable from the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). As secondary hypoadrenalism requires a specific treatment, a high index of suspicion and appropriate hormonal testing are required to differentiate between these two entities. We retrospectively studied 10 patients with a previously undiagnosed hypothalamic-pituitary disease who presented with an acute symptomatic hyponatremia. Mean age (+/-SD) was 65.1+/-8.4 yr. Mean serum sodium was 120.7+/-2.9 nmol/l and urinary osmolality, 453.9+/-74 mosmol/kg. Serum creatinine, urea and uric acid were low. Mean serum morning cortisol was low, 104.0+/-55.2 nmol/l. High-dose ACTH test showed adequate increment of serum cortisol in 3 out of 7 patients tested. Two of these 3 patients did not respond adequately to the low-dose ACTH test. Endocrine evaluation disclosed partial or complete hypopituitarism in all 10 patients. Six patients had pituitary macroadenomas, one had a craniopharyngioma, one patient had a large aneurysm of the internal carotid with sellar destruction and two others had empty sella. Treatment by fluid restriction did not affect serum sodium levels significantly. In contrast, all patients achieved normal sodium when treated by glucocorticosteroid. Central hypoadrenalism should be considered in any patient presenting with hyponatremia with high urine osmolality. Low-dose ACTH test should be performed and followed by appropriate endocrine and imaging studies. Hyponatremia in these patients is promptly corrected by glucocorticosteroid replacement.

Intractable nausea attributable to isolated deficiency of adrenocorticotropic hormone: prompt resolution after administration of glucocorticoid

OBJECTIVE

To highlight the vague symptoms of isolated adrenocorticotropic hormone (ACTH) deficiency and suggest helpful diagnostic tests and appropriate management.

METHODS

We present a detailed case report, including clinical and laboratory findings, and discuss the diagnostic approach to this rare disorder of isolated ACTH deficiency.

RESULTS

A 74-year-old woman had persistent severe nausea and other vague symptoms. Elaborate testing during a period of several weeks failed to determine the cause. Ultimately, isolated ACTH deficiency was diagnosed after documentation of subnormal random serum cortisol and ACTH levels as well as urinary free cortisol concentrations. Moreover, the nausea and other symptoms abated after administration of glucocorticoid. The patient was then maintained on orally administered dexamethasone, 0.5 mg twice daily, for 4 to 6 weeks, at which time the diagnosis was confirmed by a subnormal cortisol response on cosyntropin stimulation testing and an unmeasurable ACTH level after overnight oral administration of metyrapone. Although the cause of this patient's isolated ACTH deficiency remained undetermined, it was thought to be autoimmune in nature because of the presence of Graves' disease.

CONCLUSION

This report emphasizes the need for recognition of symptoms, appropriate testing to confirm the diagnosis, and prompt treatment with glucocorticoids in patients with isolated ACTH deficiency.