Abnormal regulation of thirst and vasopressin secretion following surgery for craniopharyngioma

Evaluation of postoperative fluctuations in plasma sodium concentration and triphasic response after pediatric craniopharyngioma resection: A French cohort study

INTRODUCTION

Disturbances in plasma sodium levels are a major complication following recent resections of craniopharyngiomas in children. They must be properly managed to avoid neurological sequelae. We aimed to describe the variations and characteristics of postoperative natremia in children who had undergone a first craniopharyngioma resection with a particular focus on the frequency of triphasic syndrome in these patients.

METHODS

Paediatric patients with craniopharyngiomas who underwent a first surgical resection in the neurosurgery department of the Hôpital Femme Mère Enfant (Lyon, France) between January 2010 and September 2021 were included in the present study and the medical records were analysed retrospectively.

RESULTS

A total of 26 patients were included. Of these, 17 (65.4%) had a postoperative course characterised by the occurrence of both initial diabetes insipidus (DI) and hyponatremia a few days later. Eight patients (30.8%) presented then with isolated and persistent DI. Patients with the triphasic syndrome had a significantly higher grade of Puget classification on MRI (1 and 2), compared to the other patients.

CONCLUSION

Dysnatremia is common after craniopharyngioma resections in children. This immediate postoperative complication is particularly difficult to manage and requires rapid diagnosis and prompt initiation of medical treatment to minimize fluctuations in sodium levels and avoid neurological sequelae.

Shifting Strategies in the Treatment of Pediatric Craniopharyngioma

PURPOSE OF REVIEW

Craniopharyngiomas represent one of the most challenging diseases to treat. Despite their benign histology, and after many decades of surgical experience and technological advancements, there is still no clear consensus regarding the most effective management for this tumor. Due to their location and aggressive local characteristics, purely surgical approaches all too often result in unacceptable morbidity.

RECENT FINDINGS

Partial resection combined with radiation therapy results in similar control rates when compared to aggressive surgery, while also minimalizing the neuro-endocrinological morbidity. In this manuscript, we describe the historical progression of the shifting strategies in the management of pediatric craniopharyngioma. Time has also altered our expectations for outcomes, evolving from purely morbidity and mortality to simple Glasgow Outcomes Scales, now to formal neuro-psychometric and quality of life data.

Disorders of Salt and Water Balance After Pituitary Surgery

Transsphenoidal surgery is the first-line treatment for many clinically significant pituitary tumors and sellar lesions. Although complication rates are low when performed at high-volume centers, disorders of salt and water balance are relatively common postoperatively. Both, or either, central diabetes insipidus (recently renamed arginine vasopressin deficiency - AVP-D), caused by a deficiency in production and/or secretion of arginine vasopressin, and hyponatremia, most commonly secondary to the syndrome of inappropriate antidiuresis, may occur. These conditions can extend hospital stay and increase the risk of readmission. This article discusses common presentations of salt and water balance disorders following pituitary surgery, the pathophysiology of these conditions, and their diagnosis and management.

Diagnosis and Management of Central Diabetes Insipidus in Adults

Central diabetes insipidus (CDI) is a clinical syndrome which results from loss or impaired function of vasopressinergic neurons in the hypothalamus/posterior pituitary, resulting in impaired synthesis and/or secretion of arginine vasopressin (AVP). AVP deficiency leads to the inability to concentrate urine and excessive renal water losses, resulting in a clinical syndrome of hypotonic polyuria with compensatory thirst. CDI is caused by diverse etiologies, although it typically develops due to neoplastic, traumatic, or autoimmune destruction of AVP-synthesizing/secreting neurons. This review focuses on the diagnosis and management of CDI, providing insights into the physiological disturbances underpinning the syndrome. Recent developments in diagnostic techniques, particularly the development of the copeptin assay, have improved accuracy and acceptability of the diagnostic approach to the hypotonic polyuria syndrome. We discuss the management of CDI with particular emphasis on management of fluid intake and pharmacological replacement of AVP. Specific clinical syndromes such as adipsic diabetes insipidus and diabetes insipidus in pregnancy as well as management of the perioperative patient with diabetes insipidus are also discussed.

[Adipsic diabetes insipidus after transsphenoidal surgery for suprasellar intraventricular]

Presented case demonstrates a rare diencephalic pathology - adipsic diabetes insipidus (ADI) with severe hypernatremia in a 58-year-old woman after ttranssphenoidal removal of stalk intraventricular craniopharyngioma. ADI was diagnosed because of hypernatremia (150-155 mmol/L), polyuria (up to 4 liters per day) and absence of thirst. Normalization of water-electrolyte balance occurred on the background of desmopressin therapy and sufficient hydration in postoperative period. After release from the hospital, the patient independently stopped desmopressin therapy and did not consume an adequate amount of fluid of the background of polyuria. This led to severe hypernatremia (155-160 mmol/L) and rough mental disorders.Patients with ADI need closely monitoring of medical condition and water-electrolyte parameters, appointment of fixed doses of desmopressin and adequate hydration.

Sleep Disorders in Patients With Craniopharyngioma: A Physiopathological and Practical Update

Sleep disorders (SDs) represent an important issue in patients with craniopharyngioma (CP). Nearly 70% of these patients complain of sleep-wake cycle alterations and/or excessive diurnal somnolence due to sleep-related breathing disorders, such as obstructive sleep apnea (OSA) and/or central hypersomnia, including secondary narcolepsy. SDs may severely reduce quality of life, increase disease-related cardiorespiratory and cardiovascular morbidity, and finally play a major role in increased long-term mortality reported on patients with CP. A major risk factor for SDs is represented by the hypothalamic syndrome, which may develop because of direct hypothalamic damage by the tumor itself and/or complications of the treatments, neurosurgery and/or radiotherapy, and typically includes permanent neuroendocrine dysfunctions, morbid obesity, and secondary metabolic disorders. Despite increasing attention to SDs in the general population, and in particular to OSA as a risk factor for cardio-metabolic diseases and excessive daytime somnolence, sleep evaluation is still not routinely proposed to patients with CP. Hence, SDs are often underdiagnosed and undertreated. The aim of this paper is to update current knowledge of the pathogenesis and prevalence of SDs in patients with CP and propose practical algorithms for their evaluation and management in clinical practice. Particular attention is paid to screening and diagnostic tools for appropriate characterization of SDs, identification of risk factors, and potential role of hypothalamic sparing surgery in the prevention of morbid obesity and SDs. Available tools in sleep medicine, including lifestyle interventions, drugs, and respiratory devices, are discussed, as well as the importance of optimal hormone replacement and metabolic interventions. Current limits in the diagnosis and treatment of SDs in patients with CP and possible future avenues for research agenda are also considered.

Relationship between postoperative hypothalamic injury and water and sodium disturbance in patients with craniopharyngioma: A retrospective study of 178 cases

OBJECTIVE

To investigate the relationship between postoperative hypothalamo-hypophyseal injury (HHI) and postoperative water and sodium disturbances in patients with craniopharyngioma.

METHODS

The medical records, radiological data, and laboratory results of 178 patients (44 children and 134 adults) who underwent microsurgery for craniopharyngioma in a single center were reviewed. Postoperative HHI was assessed using magnetic resonance imaging. Structural defects of the hypothalamo-hypophyseal system (pituitary, pituitary stalk, floor and lateral wall of the third ventricle) were assessed in four standard T1-weighted images. The defect of each structure was assigned 1 score (0.5 for the unilateral injury of the third ventricle wall), and a HHI score was calculated.

RESULTS

The number of patients with HHI scores of 0-1, 2, 2.5-3, and >3 was 35, 49, 61, and 33, respectively. Diabetes insipidus (DI) worsened in 56 (31.5%) patients with preoperative DI, while 119 (66.9%) patients were diagnosed with new-onset DI. Hypernatremia and hyponatremia developed in 127 (71.3%) and 128 (71.9%) patients after surgery, respectively. Syndrome of inappropriate antidiuresis occurred in 97(54.5%) patients. During hospitalization, hypernatremia recurred in 33 (18.5%) patients and in 54 (35.7%) during follow-up, of which 18 (11.9%) were severe. DI persisted in 140 (78.7%) patients before discharge. No relationship was found between the HHI score and incidence of early DI, hyponatremia, syndrome of inappropriate diuretic hormone, or prolonged DI. Compared with patients with a score of 0-1, those with scores =2.5-3 (OR = 5.289, 95% CI:1.098-25.477, P = 0.038) and >3 (OR = 10.815, 95% CI:2.148-54.457, P = 0.004) had higher risk of developing recurrent hypernatremia. Patients with a score >3 had higher risk of developing severe hypernatremia during hospitalization (OR = 15.487, 95% CI:1.852-129.539, P = 0.011) and at follow-up (OR = 28.637, 95% CI:3.060-267.981, P = 0.003).

CONCLUSIONS

The neuroimaging scoring scale is a simple tool to semi-quantify HHI after surgery. Recurrent and severe hypernatremia should be considered in patients with a high HHI score (>2.5). An HHI score >3 is a potential predictor of adipsic DI development. Preventive efforts should be implemented in the perioperative period to reduce the incidence of potentially catastrophic complications.

Management of Diabetes Insipidus following Surgery for Pituitary and Suprasellar Tumours

Central diabetes insipidus (CDI) is a common complication after pituitary surgery. However, it is most frequently transient. It is defined by the excretion of an abnormally large volume of dilute urine with increasing serum osmolality. The reported incidence of CDI after pituitary surgery ranges from 0–90%. Large tumour size, gross total resection and intraoperative cerebrospinal fluid leak usually pose an increased risk of CDI as observed with craniopharyngioma and Rathke’s cleft cysts. CDI can be associated with high morbidity and mortality if not promptly recognised and treated on time. It is also essential to rule out other causes of postoperative polyuria to avoid unnecessary pharmacotherapy and iatrogenic hyponatremia. Once the diagnosis of CDI is established, close monitoring is required to evaluate the response to treatment and to determine whether the CDI is transient or permanent. This review outlines the evaluation and management of patients with CDI following pituitary and suprasellar tumour surgery to help recognise the diagnosis, consider the differential diagnosis, initiate therapeutic interventions and guide monitoring and long-term management.

Incidence and Possible Predictors of Sodium Disturbance After Craniopharyngioma Resection Based on QST Classification

OBJECTIVE

Serum sodium abnormalities are one of the most common manifestations after radical craniopharyngioma (CP) excision. The aim of this study was to report the incidence and possible predictors of serum sodium disturbance and explore features of sodium destabilization manifestation among QST classification results after CP resection.

METHODS

A retrospective analysis was performed of clinical, biochemical, radiologic, and operative data for 134 successive patients who underwent primary CP removal between September 2016 and March 2018. Univariate and multivariate analyses were conducted to determine predictors.

RESULTS

Sixty patients (44.8%) experienced hyponatremia and 67 patients (50%) hypernatremia; the median time of onset was 6 days and the first day after surgery, respectively. The incidence, onset, severity, and type of sodium disturbance among different types of CP differed significantly based on statistical tests (P < 0.05). Sodium disturbance was more common and severe in patients with type T tumors (P < 0.05). Age, tumor type, and preoperative diabetes insipidus were independent prognostic factors for obvious disorders of serum sodium.

CONCLUSIONS

Hyponatremia/hypernatremia is common after primary CP resection. The site of tumor origin has a direct effect on the growth pattern of CP, which may serve as a useful index for anticipating sodium perturbation after surgery. The level of sodium in children and patients with type T tumors, preoperative diabetes insipidus should be monitored closely throughout hospitalization.

Postoperative diabetes insipidus: how to define and grade this complication?

PURPOSE

Although transient diabetes insipidus (DI) is the most common complication of pituitary surgery, there is no consensus on its definition. Polyuria is the most overt symptoms of DI, but can also reflect several physiological adaptive mechanisms in the postoperative phase. These may be difficult to distinguish from and might coincide with DI. The difficulty to distinguish DI from other causes of postoperative polyuria might explain the high variation in incidence rates. This limits interpretation of outcomes, in particular complication rates between centers, and may lead to unnecessary treatment. Aim of this review is to determine a pathophysiologically sound and practical definition of DI for uniform outcome evaluations and treatment recommendations.

METHODS

This study incorporates actual data and the experience of our center and combines this with a review of literature on pathophysiological mechanisms and definitions used in clinical studies reporting of postoperative DI.

RESULTS

The occurrence of excessive thirst and/or hyperosmolality or hypernatremia are the best indicators to discriminate between pathophysiological symptoms and signs of DI and other causes. Urine osmolality distinguishes DI from osmotic diuresis.

CONCLUSIONS

To improve reliability and comparability we propose the following definition for postoperative DI: polyuria (urine production > 300 ml/hour for 3 h) accompanied by a urine specific gravity (USG) < 1.005, and at least one of the following symptoms: excessive thirst, serum osmolality > 300 mosmol/kg, or serum sodium > 145 mmol/L. To prevent unnecessary treatment with desmopressin, we present an algorithm for the diagnosis and treatment of postoperative DI.

Congenital pituitary cyst resulting in adipsic central diabetes insipidus and secondary hypernatremia in a cat

Case summary

A 9-month-old intact female domestic mediumhair cat presented with a 5-month history of obtundation, lethargy, hypernatremia (181 mmol/l; reference interval [RI] 151–158 mmol/l), hyperchloremia (142 mmol/l; RI 117–126 mmol/l), azotemia (blood urea nitrogen 51 mg/dl; RI 18–33 mg/dl), creatinine 3.0 mg/dl (RI 1.1–2.2 mg/dl), hyperphosphatemia (8.3 mg/dl; RI 3.2–6.3 mg/dl) and total hypercalcemia (11.4 mg/dl; RI 9–10.9 mg/dl), with concurrent polyuria with adipsia. Neurologic evaluation revealed proprioceptive deficits, and this finding paired with a history of focal seizure-like activity despite improving sodium concentrations suggested a cerebrothalamic lesion. For this reason, and historical and biochemical findings consistent with adipsic diabetes insipidus (DI), MRI of the brain was performed, which revealed a lesion of the hypophyseal fossa consistent with a pituitary cyst. Given the patient’s age and the timeline of clinical signs, a congenital pituitary cyst was strongly suspected. The patient was managed initially with intravenous fluids to correct the hypernatremia, then managed for more than 4 years with topical ocular desmopressin acetate administration and free water administered through a feeding tube. This cat’s clinical diagnosis included a congenital pituitary cyst with subsequent central DI and primary adipsia.

Relevance and novel information

The clinical presentations of primary adipsia or central DI are both rare in cats. This is the first report to describe these conditions occurring in a cat owing to a congenital pituitary cyst and describes successful long-term management of this condition.

Disorders of hypothalamic function: Insights from Prader-Willi syndrome and the effects of craniopharyngioma

Either physical damage or being born with a specific genetic abnormality can impact on the functioning of the hypothalamus, resulting in diverse physical manifestations and/or specific behavior disorders. The impact of physical damage due to craniopharyngioma (CP) and/or surgery to remove a craniopharyngioma is compared and contrasted with the impact resulting from the genetic abnormalities associated with Prader-Willi syndrome (PWS). Similarities between PWS and CP posttreatment include hyperphagia and weight gain, low growth hormone levels, low bone density in adults, hypogonadism, disturbed temperature regulation, disturbed sleep and daytime sleepiness, memory difficulties, and problems with behavior and with peer relationships. These disturbances are an indication of the hypothalamus's central role in homeostasis. Most of the abnormalities appear to be more severe postoperatively in people with CP. Differences include higher ghrelin levels in PWS, complete absence of pituitary hormones in many cases of CP, higher incidence of thyroid dysfunction in CP, "growth without growth hormone" in obese children with CP, different types of diabetes (diabetes insipidus in CP and diabetes mellitus in PWS), and evidence of developmental delay and low IQ in people with PWS.

Adipsic diabetes insipidus

Adipsic diabetes insipidus (ADI) is a rare but devastating disorder of water balance with significant associated morbidity and mortality. Most patients develop the disease as a result of hypothalamic destruction from a variety of underlying etiologies. Damage to osmolar-responsive neuroreceptors, primarily within the supraoptic and paraventricular nuclei, results in impaired production and release of arginine vasopressin (AVP). Important regulating circuits of thirst sense and drive are regionally colocalized with AVP centers and therefore are also injured. Patients with central diabetes insipidus with impaired thirst response, defined as ADI, suffer from wide swings of plasma osmolality resulting in repeated hospitalization, numerous associated comorbidities, and significant mortality. Treatment recommendations are based largely on expert advice from case series owing to the rarity of disease prevalence. Acute disease management focuses on fixed dosing of antidiuretic hormone analogues and calculated prescriptions of obligate daily water intake. Long-term care requires patient/family education, frequent reassessment of clinical and biochemical parameters, as well as screening and treatment of comorbidities.

[Central diabetes insipidus after resection of sellar-suprasellar tumors: prevalence and predictors of manifestation]

Central diabetes insipidus is a neuroendocrine disorder caused by disturbances in antidiuretic hormone release. The last one is responsible for fluid and electrolyte balance regulation. The most common cause of diabetes insipidus is resection of sellar-suprasellar tumors followed by damage to hypothalamic nuclei responsible for antidiuretic hormone release, disruption of antidiuretic hormone transportation from hypothalamus or its release by neurohypophysis. According to various data, postoperative diabetes insipidus occurs in 13-30% of cases. The highest risk of diabetes insipidus is observed after resection of craniopharyngioma, Rathke's cleft cyst and ACTH-releasing pituitary microadenoma. This review is devoted to prevalence and predictors of diabetes insipidus after resection of sellar-suprasellar tumors.

Management of central diabetes insipidus

The treatment of central diabetes insipidus has not changed significantly in recent decades, and dDAVP and replacement of free water deficit remain the cornerstones of treatment. Oral dDAVP has replaced nasal dDAVP as a more reliable mode of treatment for chronic central diabetes insipidus. Hyponatraemia is a common side effect, occurring in one in four patients, and should be avoided by allowing a regular break from dDAVP to allow a resultant aquaresis. Hypernatraemia is less common, and typically occurs during hospitalization, when access to water is restricted, and in cases of adipsic DI. Management of adipsic DI can be challenging, and requires initial inpatient assessment to establish dose of dDAVP, daily fluid prescription, and eunatraemic weight which can guide day-to-day fluid targets in the long-term.

Symptomatic Cerebral Vasospasm After Transsphenoidal Tumor Resection: Two Case Reports and Systematic Literature Review

Cerebral vasospasm is a rare life-threatening complication of transsphenoidal surgery (TSS). We report our experience with two cases of symptomatic vasospasm after endoscopic TSS, alongside a systematic review of published cases. Two patients who underwent endoscopic TSS for resection of a tuberculum sella meningioma (case 1) and pituitary adenoma (case 2) developed symptomatic vasospasm. Clinical variables, including demographics, histopathology, the extent of subarachnoid hemorrhage (SAH), diabetes insipidus (DI), day of vasospasm, vasospasm symptoms, vessels involved, management, and clinical outcome, were retrospectively extracted. We subsequently reviewed published cases of symptomatic post-TSS vasospasm. Including our two cases, we identified 34 reported cases of TSS complicated by symptomatic vasospasm. Female patients accounted for 20 (58.8%) of 34 cases. The average age was 48.1 ± 12.9 years. The majority of patients exhibited postoperative SAH (70.6%). The average delay to vasospasm presentation was 8.5 ± 3.6 days. The majority of patients exhibited vasospasm in multiple vessels, typically involving the anterior circulation. Hemodynamic augmentation with hemodilution, hypertension, and hypervolemia was the most common treatment. Death occurred in six (17.6%) of 34 patients. Common deficits included residual extremity weakness (17.6%), pituitary insufficiency (8.8%), and cognitive deficits (8.8%). Symptomatic vasospasm is a rare, potentially fatal complication of TSS. The most consistent risk factor is SAH. Early diagnosis requires a high index of suspicion when confronted with intractable DI, acute mental status change, or focal deficits in the days after TSS. Morbidity and death are significant risks in patients with this complication.

Daily Sodium Monitoring and Fluid Intake Protocol: Preventing Recurrent Hospitalization in Adipsic Diabetes Insipidus

Management of diabetes insipidus (DI) is usually facilitated by an intact thirst mechanism prompting water ingestion in times of rising osmolality. Maintenance of eunatremia can be quite difficult in patients with DI and adipsia because of the absence of this homeostatic mechanism. Few published protocols for management of these complex cases exist. We report a case of a 16-year-old girl who had a diagnosis of craniopharyngioma with preoperative hypopituitarism and central DI. She underwent transsphenoidal resection in 2013 and additionally developed postoperative cognitive impairment and hypothalamic dysfunction, including adipsia. She subsequently experienced widely dysregulated sodium levels, necessitating inpatient care ∼30% of days in 2014 and 2015. We created a protocol for this patient that uses a fixed daily dose of subcutaneous DDAVP combined with daily modulation of fluid intake based on daily serum sodium measurement. The protocol provides guidance for the day's fluid intake based on both the current sodium result and the rate of change from the previous day. Since the adoption of the protocol in June 2016, the patient has had a dramatic reduction in hospitalizations. Use of a protocol for providing recommendations for fluid intake based on the sodium level and rate of change may help to maintain normal sodium levels in such patients, decreasing hospitalization and improving quality of life.

Management of hypothalamic disease in patients with craniopharyngioma

Patients with craniopharyngioma experience excess morbidity and mortality when compared with the background population and with other hypopituitary patients. Large, suprasellar tumours which form micropapillae into surrounding structures can cause hypothalamic damage before any therapeutic intervention; attempted gross total resection can lead to hypothalamic obesity, sleep disorders, thirst disorders and dysregulation of temperature as well as panhypopituitarism. The management of tumour bulk and the pathophysiology of hypothalamic complications have been reviewed extensively. We present a practical, clinical approach to management of hypothalamic disease in a patient with craniopharyngioma and highlight potential targets for future pharmacological or surgical intervention.

Diagnosis and management of central diabetes insipidus in adults

Central diabetes insipidus (CDI) is characterized by hypotonic polyuria due to impairment of AVP secretion from the posterior pituitary. In clinical practice, it needs to be distinguished from renal resistance to the antidiuretic effects of AVP (nephrogenic DI), and abnormalities of thirst appreciation (primary polydipsia). As nephrogenic diabetes insipidus is rare in adults, unless they are treated with lithium salts, the practical challenge is how to differentiate between CDI and clinical disorders of excess thirst. The differential diagnosis is usually straight forward, but the recommended gold standard test, the water deprivation test, is not without interpretative pitfalls. The addition of the measurement of plasma AVP concentrations improves diagnostic accuracy, but the radioimmunoassay for AVP is technically difficult, and is only available in a few specialized centres. More recently, the measurement of plasma copeptin concentrations has been claimed to provide a reliable alternative to measurement of plasma AVP, without the sampling handling challenges. In addition, the measurement of thirst ratings can help the differentiation between CDI and primary polydipsia. Once the diagnosis of CDI is biochemically certain, investigations to determine the cause of AVP deficiency are needed. In this review, we will outline the diagnostic approach to polyuria, revisit the caveats of the water deprivation test and review recent data on value of adding AVP/copeptin measurement. We will also discuss treatment strategies for CDI, with analysis of potential complications of treatment.

Adipsic diabetes insipidus in adult patients

INTRODUCTION

Adipsic diabetes insipidus (ADI) is a very rare disorder, characterized by hypotonic polyuria due to arginine vasopressin (AVP) deficiency and failure to generate the sensation of thirst in response to hypernatraemia. As the sensation of thirst is the key homeostatic mechanism that prevents hypernatraemic dehydration in patients with untreated diabetes insipidus (DI), adipsia leads to failure to respond to aquaresis with appropriate fluid intake. This predisposes to the development of significant hypernatraemia, which is the typical biochemical manifestation of adipsic DI.

METHODS

A literature search was performed to review the background, etiology, management and associated complications of this rare condition.

RESULTS

ADI has been reported to occur in association with clipping of an anterior communicating artery aneurysm following subarachnoid haemorrhage, major hypothalamic surgery, traumatic brain injury and toluene exposure among other conditions. Management is very difficult and patients are prone to marked changes in plasma sodium concentration, in particular to the development of severe hypernatraemia. Associated hypothalamic disorders, such as severe obesity, sleep apnoea and thermoregulatory disorders are often observed in patients with ADI.

CONCLUSION

The management of ADI is challenging and is associated with significant morbidity and mortality. Prognosis is variable; hypothalamic complications lead to early death in some patients, but recent reports highlight the possibility of recovery of thirst.

Heterogenous patterns of recovery of thirst in adult patients with adipsic diabetes insipidus

BACKGROUND

The natural history of adipsic diabetes insipidus (ADI) is not well described, and reports of recovery of thirst are rare.

DESIGN AND METHODS

Case histories presentation. ADI was identified by demonstrating absent thirst and arginine vasopressin (AVP) responses to hypertonic saline infusion.

RESULTS

Twelve patients with ADI were identified (craniopharyngioma 5, anterior communicating artery aneurysm (ACOM) repair 4, congenital 1, neurosarcoidosis 1, prolactinoma 1). Three patients died. Six patients had permanent ADI. Three patients had recovery of thirst, with a heterogenous pattern of recovery. In the first case, ADI had developed after clipping of an ACOM aneurysm. Ten years after surgery; he sensed the return of thirst; repeated hypertonic saline infusion showed recovery of thirst and AVP secretion. In the second case, a 41-year-old female with an intrasellar craniopharyngioma developed post-operative ADI with persistent hypernatremia. Two years post-operatively, she complained of thirst, and hypertonic saline infusion showed normalization of thirst but absent AVP responses, confirming recovery of thirst, but with persistent diabetes insipidus (DI). In the third case, a 29-year-old Caucasian had craniotomy and radiotherapy for craniopharyngioma and developed ADI post-operatively. Eight years post-op, she presented with thirst, seizures and pNa of 112 mmol/l. Hypertonic saline infusion showed persistent DI but thirst responses typical of compulsive water drinking; she has had recurrent hyponatraemia since then.

CONCLUSIONS

We report that 3/12 patients with ADI recovered thirst after longstanding adipsia with heterogenous pattern of recovery. Both the mortality of 25% and the recovery rate of 25% should be considered when planning long-term surveillance.

Management of electrolyte and fluid disorders after brain surgery for pituitary/suprasellar tumours

Disturbances in salt and water balances are relatively common in children after brain surgeries for suprasellar and pituitary tumours, presenting diagnostic and therapeutic challenges. Although hypernatraemia associated with central diabetes insipidus is commonly encountered, it is hyponatraemia (HN) that poses more of a diagnostic dilemma. The main differential diagnoses causing HN are the syndrome of inappropriate antidiuretic hormone secretion, marked by inappropriate retention of water, and cerebral salt wasting, characterized by polyuria and natriuresis. Diagnosis and management can be even more difficult when these conditions precede or coexist with each other. These diagnostic and therapeutic dilemmas are discussed in detail in this review.

Water and electrolyte disorders at long-term post-treatment follow-up in paediatric patients with suprasellar tumours include unexpected persistent cerebral salt-wasting syndrome

BACKGROUND

Patients with brain tumours have a high risk of water and electrolyte disorders (WED). Postsurgery diabetes insipidus (DI) may be transient or permanent, the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cerebral salt-wasting syndrome (CSWS) are usually transient.

METHODS

Retrospective study, including patients with suprasellar tumours, treated at Hôpital Necker, Institut Gustave-Roussy or Institut Curie, in Île-de-France, between 2007 and 2011. WED were noted if they persisted >1 month after surgery.

RESULTS

159 patients were included, 54.1% girls, 43.9% boys. Tumour types were: glioma (43.4%), craniopharyngioma (43.4%), germinoma (11.3%), others (1.9%). Age at diagnosis was 7.1 ± 4.6 years. The median time from end of treatment was 1.9 (0-7.8) years. DI was the most frequent disorder after tumour treatment (50.3%) and was significantly associated with surgery (p < 0.001). Persistent CSWS was present in 3.6%, persistent SIADH in 1.3%. Two cases of hypernatraemia were due to adipsia. Thyrotropin deficiency after treatment was noted in 68.9% of patients tested, adrenocorticotropin deficiency in 66.2%.

CONCLUSIONS

Patients with suprasellar tumours have a high incidence of long-term WED, mainly DI. Assessment of thyrotroph and corticotroph function, and thirst sensation, is necessary to diagnose and manage these disorders correctly. CSWS may be persistent in few patients and requires special attention to prescribe the appropriate care.

Management of diabetes insipidus and adipsia in the child

Central diabetes insipidus (CDI) is a complex and heterogeneous clinical syndrome affecting the hypothalamic-neurohypophyseal network and water balance. A recent national surveillance in Denmark showed a prevalence rate of twenty-three CDI patients per 100,000 inhabitants in five years. The differential diagnosis between several presenting conditions with polyuria and polydipsia is puzzling, and the etiological diagnosis of CDI remains a challenge before the identification of an underlying cause. For clinical practice, a timely diagnosis for initiating specific treatment in order to avoid central nervous system damage, additional pituitary defects and the risk of dissemination of germ cell tumor is advisable. Proper etiological diagnosis can be achieved via a series of steps that start with careful clinical observation of several signs and endocrine symptoms and then progress to more sophisticated imaging tools. This review summarizes the best practice and approach for the diagnosis and treatment of patients with CDI.

Abnormal plasma sodium concentrations in patients treated with desmopressin for cranial diabetes insipidus: results of a long-term retrospective study

CONTEXT AND OBJECTIVE

Patients with cranial diabetes insipidus (CDI) are at risk of developing both hypernatraemia and hyponatraemia, due to the condition itself or secondary to treatment with vasopressin-analogues or during administration of i.v. fluids. We aimed to assess the frequency and impact of dysnatraemias in the inpatient (INPT) and outpatient (OPT) setting in desmopressin-treated CDI, comparing those with normal thirst with those with abnormal thirst.

DESIGN

The study included 192 patients with cranial diabetes, who were identified from the Beaumont Pituitary Database, a tertiary referral centre. Retrospective case note audit was performed and the clinical and biochemical information of 147 patients with CDI were available for analysis.

RESULTS

A total of 4142 plasma sodium measurements for 137 patients with normal thirst, and 385 plasma sodium measurements for ten patients with abnormal thirst were analysed. In those with normal thirst, the most common OPT abnormality was mild hyponatraemia (pNa(+) 131-134  mmol/l) in 27%, while 14.6% had more significant hyponatraemia (pNa(+) ≤130  mmol/l). Of those patients with normal thirst, 5.8% were admitted due to complications directly related to hyponatraemia. Compared with patients with normal thirst, those with abnormal thirst were more likely to develop significant OPT hypernatraemia (20% vs 1.4%, P=0.02) and significant INPT hyponatraemia (50% vs 11.1%, P 0.02).

CONCLUSION

OPT management of CDI is complicated by a significant incidence of hyponatraemia. In contrast, OPT hypernatraemia is almost exclusively a complication seen in adipsic CDI, who also had more frequent INPT hyponatraemia. CDI associated with thirst disorder requires increased physician attention and patient awareness of potential complications.

From cerebral salt wasting to diabetes insipidus with adipsia: case report of a child with craniopharyngioma

Craniopharyngioma is associated with a wide and interesting variety of sodium states both by itself and following surgical resection. These are often challenging to diagnose, especially given their dynamic nature during the perioperative course. We present the case of a boy with craniopharyngioma who had hyponatremia due to cerebral salt wasting preoperatively, developed diabetes insipidus (DI) intraoperatively and proceeded to develop hypernatremia with adipsic DI.

CONCLUSION

Cerebral salt wasting is a rare presenting feature of craniopharyngioma. Postoperative DI can be associated with thirst abnormalities including adipsia due to hypothalamic damage; careful monitoring and a high index of suspicion are required for its detection. Adipsic DI is a difficult condition to manage; hence a conservative surgical approach is suggested.

Endocrine aspects and sequel in patients with craniopharyngioma

A craniopharyngioma (CP) is an embryonic malformation of the sellar and parasellar region. The annual incidence is 0.5-2.0 cases/million per year and approximately 60% of CP is seen in adulthood. The therapy of choice is surgery, followed by cranial radiotherapy in about half of the patients. Typical initial manifestations at diagnosis in children are symptoms of elevated intracranial pressure, visual disturbances and hypopituitarism. CPs have the highest mortality of all pituitary tumours. The standardised overall mortality rate varies from 2.88 to 9.28 in cohort studies. Adults with CP have a 3-19-fold higher cardiovascular mortality in comparison to the general population. Women with CP have an even higher risk. The long-term morbidity is substantial with hypopituitarism, increased cardiovascular risk, hypothalamic damage, visual and neurological deficits, reduced bone health and reduction in quality of life and cognitive function.

Adipsic diabetes insipidus in pediatric patients

OBJECTIVE

To present symptoms, complications and proposition of management protocol in children diagnosed with adipsic diabetes insipidus (aDI).

METHODS

Clinical and biochemical analysis of six pediatric patients diagnosed with aDI, four boys aged 5, 13, 16, and 17 y and two girls aged 2.5 and 10 y. The etiology of aDI was germinoma (n = 2), extensive surgery due to optic glioma (n = 1) and astrocytoma (n = 1), congenital brain malformations (n = 1) and complications secondary to bacterial meningitis (n = 1). Two patients had severely impaired vision and two had hemiparesis.

RESULTS

In all the patients, loss of thirst reflex was observed. The serum electrolytes in all patients showed sodium concentration from 159 to 176.6 mmol/L with plasma osmolality from above 297 mOsmol/kg. Polyuria was absent in three most severely dehydrated patients on admission. In two patients in whom DDAVP (1-desamino-8-D-arginine vasopressin; Desmopressin) therapy was withdrawn based on lack of polyuria deep venous thrombosis developed.

CONCLUSIONS

Lack of polydipsia and polyuria, the key symptoms of diabetes insipidus (DI), may delay the diagnosis of aDI and may lead to severe complications of chronic hyperosmolar status. The fluid intake in patients diagnosed with aDI need to be supervised daily based on calculated constant volume of oral fluids, daily measurements of fluid balance, body weight and sodium levels, especially in patients whose vision is compromised or who are physically unable to take care of themselves.

Late recovery of cranial diabetes insipidus following pituitary surgery

BACKGROUND

Diabetes insipidus (DI) is common following surgery for a pituitary/sellar lesion. Postoperative DI persisting beyond a few weeks is usually regarded as permanent, requiring lifelong desmopressin therapy.

CASE PRESENTATION

A 16-year-old girl underwent pituitary decompression following a pituitary tumour apoplexy. She developed DI with thirst and hypotonic polyuria in the immediate post-operative period, which was controlled with parenteral DDAVP. Her symptoms persisted and she was discharged on oral desmopressin. Subsequently, she commenced growth hormone replacement. A water deprivation test 6 weeks postoperatively confirmed persistent DI with failure to concentrate urine after 8 hours of dehydration. She was maintained on desmopressin and reported intense thirst and polyuria every time she delayed taking the medication up until 1 year postoperatively. After 1 year, she complained of bloating and stopped taking desmopressin but her symptoms did not recur. A repeat water deprivation test confirmed very late resolution of DI with normal urinary concentration. She has remained asymptomatic ever since.

CONCLUSION

Delayed recovery of normal posterior pituitary function is exceptionally rare. We hypothesise that the underlying mechanism may be the revascularisation and regeneration of the posterior pituitary tissues or of the axons terminating in the posterior pituitary.

Mortality and morbidity in adult craniopharyngioma

A craniopharyngioma (CP) is an embryonic malformation of the sellar and parasellar region. The annual incidence is 0.5-2.0 cases/million/year and approximately 60 % of CP are seen in adulthood. Craniopharyngiomas have the highest mortality of all pituitary tumors. Typical initial manifestations at diagnosis in adults are visual disturbances, hypopituitarism and symptoms of elevated intracranial pressure. The long-term morbidity is substantial with hypopituitarism, increased cardiovascular risk, hypothalamic damage, visual and neurological deficits, reduced bone health, and reduction in quality of life and cognitive function. Therapy of choice is surgery, followed by cranial radiotherapy in about half of the patients. The standardised overall mortality rate varies 2.88-9.28 in cohort studies. Patients with CP have a 3-19 fold higher cardiovascular mortality in comparison to the general population. Women with CP have an even higher risk.

Craniopharyngioma in adults

Craniopharyngiomas are slow growing benign tumors of the sellar and parasellar region with an overall incidence rate of approximately 1.3 per million. During adulthood there is a peak incidence between 40 and 44 years. There are two histopathological types, the adamantinomatous and the papillary type. The later type occurs almost exclusively in adult patients. The presenting symptoms develop over years and display a wide spectrum comprising visual, endocrine, hypothalamic, neurological, and neuropsychological manifestations. Currently, the main treatment option consists in surgical excision followed by radiation therapy in case of residual tumor. Whether gross total or partial resection should be preferred has to be balanced on an individual basis considering the extent of the tumor (e.g., hypothalamic invasion). Although the overall long-term survival is good it is often associated with substantial morbidity. Preexisting disorders are often permanent or even exacerbated by treatment. Endocrine disturbances need careful replacement and metabolic sequelae should be effectively treated. Regular follow-up by a multidisciplinary team is a prerequisite for optimal outcome of these patients.

Objective assessment of thirst recovery in patients with adipsic diabetes insipidus

Adipsic diabetes insipidus (ADI) is characterised by impaired thirst and defective AVP secretion. We have assessed the thirst response to graded osmotic stimulation using a visual analog scale (VAS) in patients with a history of ADI following surgery for a craniopharyngioma. The patients were thought to be regaining their thirst response but we wanted to confirm that this was the case objectively before relaxing their strict fluid balance regimen. Three patients with adipisa in the presence of hypernatremia following surgery for a craniopharyngioma are described. Their median age at surgery was 13 years (range 11-15 years). All patients had previously demonstrated no desire to drink despite a serum osmolality in excess of 300 mOsmol/kg. Fluid balance was maintained postoperatively with a regimen involving a fixed daily fluid intake and DDAVP dose together with daily weights and regular assessment of capillary sodium concentrations. Patients were thought to be regaining thirst sensation and so were assessed by hypertonic saline infusion (HSI) with thirst measured using a VAS. Patients underwent a HSI test 4, 6 and 9 months post surgery. All had abnormally low AVP production at raised plasma osmolalities but the visual analogue scale confirmed partial or complete thirst recovery. The intensive regimen used to maintain stable serum sodium concentrations was relaxed without the patients subsequently developing a significant hyperosmolar state. We have shown objective recovery of thirst perception in patients with adipsia within 9 months of surgery, despite persistence of cranial diabetes insipidus. These observations indicate that both osmoreceptors regulating thirst and their efferent pathways demonstrate more plasticity than those regulating AVP production. The HSI and thirst VAS are an objective way of assessing patients known to have ADI who are thought to be recovering thirst perception.

Modern radiotherapy approaches in the management of craniopharyngiomas

An audit of treatment regimens at presentation, recurrence and survival rates spanning 37 years were reviewed for children and adults with craniopharyngioma treated at The Prince of Wales or the Sydney Children's hospitals. Eligibility criteria stipulated all patients (n=41) received radiotherapy as part of their treatment course. The primary end point for evaluation was the incidence of radiological progression post-radiotherapy, and secondary end-points were the symptomatic and hormonal status post-radiotherapy. There were 12 paediatric patients (age, <16 years) and 29 adults (age range, 16-80 years). Of the 41 patients, 39 had a suprasellar tumour component, and 38 had radiologically persistent disease post-surgery. Four patients were treated by radiosurgery (median volume treated, 3.5 cm(3)); four patients progressed post-radiotherapy, of whom two were salvaged by further radiotherapy, one succumbed to progressive local disease, and one had a small intrasellar recurrence surgically resected. Progression-free survival (95.12%) was followed for up to 23 years. Thus, subtotal resection and the modern radiotherapy approach is likely to provide excellent patient and disease outcomes.

Somnolence in adult craniopharyngioma patients is a common, heterogeneous condition that is potentially treatable

CONTEXT AND OBJECTIVE

Somnolence and obesity are prevalent in craniopharyngioma patients. We hypothesized that somnolence was because of obstructive sleep apnoea in craniopharyngioma patients.

DESIGN, PATIENTS AND MEASUREMENTS

We assessed prevalence of somnolence and sleep apnoea in 28 craniopharyngioma and 23 obese controls attending a tertiary referral centre, by means of the Epworth Sleepiness Score (ESS) and polysomnography. All subjects with sleep apnoea were offered continuous positive airway pressure therapy (CPAP) or modafinil. All craniopharyngioma patients, with unexplained somnolence, were offered modafinil.

RESULTS

Somnolence was reported by 20/28 (71·5%) craniopharyngioma patients and 4/23 (17%) obese subjects (P < 0·001). Median ESS was 7·5 (IQR 6, 10·7) in craniopharyngioma patients and 4·0 (4,8) in controls, P < 0·01. Eleven somnolent craniopharyngioma patients had obstructive sleep apnoea, in whom treatment led to a reduction in ESS by 6·4 ± 1·4, P = 0·01. Among the remaining nine patients, five were offered modafinil therapy, of whom four had benefit, three were not compliant with hormone replacement, and one died before intervention. There was no difference in the prevalence of obstructive sleep apnoea between craniopharyngioma (n = 13, 46%) and obese subjects (n = 14, 61%, P = 0·4). Body mass index (BMI) does not correlate with apnoea hypopnoea index [apnoea - hypopnoea index (AHI), r = 0·25, P = 0·08], which suggests that obesity alone does not explain the prevalence of sleep apnoea in craniopharyngioma patients.

CONCLUSIONS

Somnolence is common in craniopharyngioma patients and in the majority is because of obstructive sleep apnoea. An additional group of somnolent craniopharyngioma patients benefits from modafinil.

Craniopharyngioma: a comparison of tumor control with various treatment strategies

OBJECT

Craniopharyngiomas have a propensity to recur after resection, potentially causing death through their aggressive local behavior in their critical site of origin. Recent data suggest that subtotal resection (STR) followed by adjuvant radiotherapy (XRT) may be an appealing substitute for gross-total resection (GTR), providing similar rates of tumor control without the morbidity associated with aggressive resection. Here, the authors summarize the published literature regarding rates of tumor control with various treatment modalities for craniopharyngiomas.

METHODS

The authors performed a comprehensive search of the English language literature to identify studies publishing outcome data on patients undergoing surgery for craniopharyngioma. Rates of progression-free survival (PFS) and overall survival (OS) were determined through Kaplan-Meier analysis.

RESULTS

There were 442 patients who underwent tumor resection. Among these patients, GTR was achieved in 256 cases (58%), STR in 101 cases (23%), and STR+XRT in 85 cases (19%). The 2- and 5-year PFS rates for the GTR group versus the STR+XRT group were 88 versus 91%, and 67 versus 69%, respectively. The 5- and 10-year OS rates for the GTR group versus the STR+XRT group were 98 versus 99%, and 98 versus 95%, respectively. There was no significant difference in PFS (log-rank test) or OS with GTR (log-rank test).

CONCLUSIONS

Given the relative rarity of craniopharyngioma, this study provides estimates of outcome for a variety of treatment combinations, as not all treatments are an option for all patients with these tumors.

Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma

Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearson’s chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ± 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33–41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, χ²P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05–5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available.

Anterior interhemispheric approach for 100 tumors in and around the anterior third ventricle

OBJECTIVE

We report our experience with anterior interhemispheric approach for tumors in and around the anterior third ventricle, including surgical technique, instrumentation, pre- and postoperative hormonal disturbances, and resection rate.

METHODS

One hundred patients with 46 craniopharyngiomas, 12 hypothalamic gliomas, 12 meningiomas, 6 hypothalamic hamartomas, and 24 other lesions were operated on using an anterior interhemispheric approach with or without opening of the lamina terminalis. This surgical approach involves no frontal sinus opening; a narrow (approximately 15-20 mm in width) access between the bridging veins, which is sufficient to remove the tumor totally; and sparing of the anterior communicating artery. Specially designed long bipolar forceps and scissors are necessary for this approach, and concomitant use of angled instruments (endoscope, aspirator, and microforceps) is required frequently. The postsurgical follow-up period varied from 4 months to 18 years.

RESULTS

Total removal of the neoplasm was accomplished in 37 of 46 patients with craniopharyngiomas (80.4%), whereas subtotal resection was performed in hypothalamic gliomas. No significant differences in pre- and postoperative hormonal disturbances were observed in 37 craniopharyngiomas and 10 hypothalamic gliomas. There was no operative mortality. Visual acuity was preserved or improved in 68 of 75 patients assessed. The Karnofsky Performance Scale score did not deteriorate in 72 of 75 patients tested.

CONCLUSION

The minimally invasive anterior interhemispheric approach, with or without opening of the lamina terminalis, is useful for removal of tumors in and around the anterior third ventricle, such as craniopharyngiomas and hypothalamic gliomas.

Osmosensation in vasopressin neurons: changing actin density to optimize function

The proportional relation between circulating vasopressin concentration and plasma osmolality is fundamental for body fluid homeostasis. Although changes in the sensitivity of this relation are associated with pathophysiological conditions, central mechanisms modulating osmoregulatory gain are unknown. Here, we review recent data that sheds important light on this process. The cell autonomous osmosensitivity of vasopressin neurons depends on cation channels comprising a variant of the transient receptor potential vanilloid 1 (TRPV1) channel. Hyperosmotic activation is mediated by a mechanical process where sensitivity increases in proportion with actin filament density. Moreover, angiotensin II amplifies osmotic activation by a rapid stimulation of actin polymerization, suggesting that neurotransmitter-induced changes in cytoskeletal organization in osmosensory neurons can mediate central changes in osmoregulatory gain.

Practical approach to childhood craniopharyngioma: a role of an endocrinologist and a general paediatrician

OBJECTIVES

The objectives of this study are to evaluate co-morbidities in patients with craniopharyngioma and to elaborate an interdisciplinary protocol of the follow-up.

PATIENTS AND METHODS

The group comprised 15 children (median age at the diagnosis, 10.1; mean follow-up period, 4 years). All patients had surgical resection of the tumour: gross total in seven, subtotal or partial removal in eight cases. Surgery was followed by radiotherapy in ten cases for tumour residue or progression. Sexual development and auxology were evaluated at diagnosis and during follow-up. Hormones were determined by chemiluminescent immunometric assays. Antidiuretic hormone dysfunction was diagnosed on the grounds of clinical symptoms, water-electrolyte balance, urine specific gravity, and serum osmolality. Metabolic control was monitored by levels of glucose, insulin, lipids, and transaminases; insulin resistance was expressed by homeostatic model assessment (HOMA) index.

RESULTS

At diagnosis, median height standard deviation score (hSDS) was -1.6 (five children being short-statured). Median change hSDS for the whole follow-up was 1.2 (four children decelerating growth). Diabetes insipidus was diagnosed in eight (within 0-1.8 years of the follow-up), hypocorticolism in eight, and hypothyroidism in 12 subjects (within 0-3.75 years for both endocrinopathies). Four patients required sex hormone replacement therapy. At diagnosis, five children were overweight; during follow-up, only four children sustained normal body mass index. Hypertransaminasaemia was found in three, dyslipidaemia in 11, and hyperinsulinaemia in seven patients (with elevated HOMA in four cases).

CONCLUSIONS

On the grounds of these observations, the management of craniopharyngioma in our institution includes repeated hormonal and metabolic assays in chosen time intervals. Early detection of co-morbidities and their management involves interdisciplinary team.

High-risk pregnancy management in women with hypopituitarism

Pregnancy after complete loss of pituitary function is uncommon. However, advances in fertility treatment have led to increased pregnancy rates in hypopituitary women. We hereby present a literature review of pregnancies affected by hypopituitarism, including a comparison with published controls; further, we add one case report of severe hypopituitarism where third-trimester oxytocin supplementation was performed. As only limited information is available on management and outcome, our purpose was to determine obstetric complications associated with deficiency of pituitary hormones. The analysis of 31 pregnancies in 27 women revealed that hypopituitary women are at increased risk: postpartum hemorrhage occurred in 8.7%, transverse lie in 16%; 42.4% of the newborns were small for gestational age. These findings are supposedly the result of uterine dysfunction caused by hormone deficiency. Oxytocin supplementation was performed with the aim to establish physiologic conditions and to prevent postpartum uterine inertia. In this case substitution may have contributed to correct fetal presentation but did not prevent postpartum hemorrhage. Further investigations into both oxytocin-dependent and -independent mechanisms regulating uterine contractions and contractility are necessary to develop strategies for prevention of uterine inertia in oxytocin-deficient pregnancies.

Craniopharyngiomas

Craniopharyngiomas are epithelial tumors arising along the path of the craniopharyngeal duct and presenting with a variety of manifestations. Their optimal management remains a subject of debate. Currently, surgical excision followed by external beam irradiation is the main treatment option. Craniopharyngiomas are associated with significant long-term morbidity and mortality rates.

Disorders of water and salt metabolism associated with pituitary disease

Disorders of water and sodium homeostasis are very common problems encountered in clinical medicine. Disorders of water metabolism are divided into hyperosmolar and hypoosmolar states, with hyperosmolar disorders characterized by a deficit of body water in relation to body solute and hypoosmolar disorders characterized by an excess of body water in relation to total body solute. This article briefly reviews the physiology of hyperosmolar and hypoosmolar syndromes, then focuses on a discussion of the pathophysiology, evaluation, and treatment of specific pre- and postoperative disorders of water metabolism in patients with pituitary lesions.

Risk of diabetes insipidus after pituitary surgery

Diabetes insipidus is a common complication of pituitary surgery, occurring acutely in 18-30% of operations. Most patients recover full posterior function but a minority sustain sufficient damage to vasopressin-secreting neurons to develop permanent diabetes insipidus. The triplephase response, comprising early transient diabetes insipidus, followed by a period of antidiuresis and hyponatremia, before resolving into permanent diabetes insipidus, is an uncommon but important variant. Diabetes insipidus is more common following surgery for craniopharyngioma compared with pituitary adenoma, and craniopharyngioma patients may develop the dangerous complication of adipsic diabetes insipidus. Diabetes insipidus is also more common following pituitary surgery for Rathke's cleft cysts and possible adrenocorticotropic hormone-secreting adenomas. The data on tumor size are conflicting but our own experience would suggest that diabetes insipidus is more common after surgery for large suprasellar tumors, particularly those with hypothalamic extension. The experience and skill of the neurosurgeon also determines the likelihood of developing diabetes insipidus. The diagnosis of postsurgical diabetes insipidus depends on excluding other forms of polyuria, including diabetes mellitus, excess intravenous fluids and therapy with diuretics or mannitol. Treatment with vasopressin analogues is almost always effective in controlling renal water excretion and normalizing plasma sodium concentrations.