© Borgis - Postępy Nauk Medycznych 11/2013, s. 762-768
*Izabella Czajka-Oraniec, Maria Stelmachowska-Banaś, Wojciech Zgliczyński
Obrazowanie okolicy przysadkowo-podwzgórzowej przy użyciu rezonansu magnetycznego u pacjentów z moczówką prostą pochodzenia centralnego
Magnetic Resonance Imaging of the Pituitary-Hypothalamic Region in the Patients with Central Diabetes Insidpidus
Department of Endocrinology, Medical Center of Postgraduate Education, Bielański Hospital, Warszawa
Head of Department: prof. Wojciech Zgliczyński, MD, PhD
Wstęp. Moczówka prosta (MP) pochodzenia centralnego jest chorobą charakteryzującą się poliurią i polidypsją, do których prowadzi nieprawidłowa synteza lub wydzielanie wazopresyny na skutek różnych stanów chorobowych uszkadzających podwzgórze, tylny płat przysadki lub szypułę. Postawienie prawidłowej diagnozy i określenie etiologii MP bywa trudne, zatem pomocne może być posłużenie się badaniem rezonansu magnetycznego (MR).
Cel pracy. Celem pracy była ocena częstości występowania i etiologii moczowki prostej wśród pacjentów hospitalizowanych w Klinice Endokrynologii CMKP w Szpitalu Bielańskim w ostatnim roku oraz analiza wynikow wykonanych u nich badań MR okolicy podwzgórzowo-przysadkowej.
Materiał i metody. Retrospektywne badanie obejmowało analizę dokumentacji medycznej. Wyszukano pacjentów hospitalizowanych w Klinice Endokrynologii CMKP w Szpitalu Bielańskim w ostatnim roku. Wyszukano pacjentów z rozpoznaniem moczówki prostej i zebrano dane dotyczące wieku, płci, przyczyn choroby i czasu jej trwania, wyników badań biochemicznych i hormonalnych oraz stosowanego leczenia. Analizowano również wyniki MR okolicy przysadkowo-podwzgórzowej.
Wyniki. U 37 spośród 1724 (2,15%) pacjentów hospitalizowanych w Klinice rozpoznano MP, natomiast tylko 9 pacjentów miało świeże objawy poliurii i polidypsji wymagające ustalenia rozpoznania (0,5%). U większości pacjentów (67,5%) stwierdzano towarzyszącą niedoczynność przedniego płata przysadki. Najczęstszą przyczyną MR była przebyta operacja guza śród- lub okołosiodłowego. Idiopatyczną MP rozpoznano tylko w 2 przypadkach. Najczęstszą zmianą stwierdzaną w MR był brak świecenia tylnego płata przysadki. Poza tym często spotykanymi nieprawidłowościami były: pogrubienie szypuły, guzy i puste siodło.
Wnioski. Moczówka prosta była rzadkim rozpoznaniem u pacjentów Kliniki. W większości przypadków szczegółowe wywiady, badanie fizykalne i badanie MR okolicy przysadkowo-podwzgórzowej pozwalały na określenie etiologii MP. Obserwowaliśmy mniej przypadków MP idiopatycznej niż opisywano w literaturze, a większość pacjentów miało MR wtórną do leczenia neurochirurgicznego dużych śród- i okołosiodłowych guzów.
Introduction. Central diabetes insipidus (DI) is a disease characterized by polyuria and polydipsia resulting from various pathologic processes and lesions destroying hypothalamus pituitary stalk or neurohypophysis that impair vasopressin synthesis or secretion. Making the proper diagnosis and finding the DI etiology is sometimes challenging and magnetic resonance (MR) evaluation could be a helpful tool.
Aim. We intended to investigate the prevalence and causes of DI and to analyse the MRI results in patients hospitalized at the Department of Endocrinology in Bielański Hospital during last year.
Material and methods. We performed a retrospective review of the medical data of patients hospitalized in the Department of Endocrinology in Bielański Hospital during last year searching for those with the diagnosis of DI. We collected data on the age, sex, causes of DI, disease duration, results of hormonal and biochemic tests and applied treatment and we evaluated the results of pituitary-hypothalamic region.
Results. Among 1724 patients hospitalized in our Department, 37 (2.15%) had DI and only 9 patients had new-onset polyuria and polydipsia (0.5%). Majority of patients had concurrent hypopituitarism (67.5%) and the most frequent cause of DI was prior surgical treatment for large sellar or parasellar tumours. Idiopatic DI was found only in 2 cases. The most consistent finding on MR images was the loss of posterior pituitary bright spot. Other abnormalities such as pituitary stalk thickening, tumours and empty sella were commonly detected.
Conclusions. DI was a rare clinical condition in our patients. In most cases detailed medical history, physical examination and MR of pituitary-hypothalamic region allowed to find its etiology. We observed less cases of idiopathic DI than it was described in the literature and majority of studied group had DI secondary to prior neurosurgical treatment for large sellar and parasellar tumours.
Central diabetes insipidus (DI) is an inherited or most commonly acquired multifactorial disease characterized by the excertion of the large volume of diluted, hypotonic urine and as a consequence excessive thirst and fluid intake (polyuria and polydipsia) (1). Vasopressin insufficiency is the reason of above symptoms. It results from inadequate synthesis or secretion of arginine vasopressin (AVP) or antidiuretic hormone (ADH) which is a peptide hormone synthesized by neuronal bodies that form supraoptic and paraventricular nuclei of the hypothalamus. Once synthesized and packed in neurosecretory granules, AVP is transported along axons through the stalk to the posterior pituitary (neurohypophysis), where it is stored for further secretion. Various pathologic processes and lesions that destroy the sites of vasopressin synthesis, transport or storage (hypothalamus, pituitary stalk or neurohypophysis) could lead to the symptoms of diabetes insipidus. The known causes include sellar and suprasellar tumours (the most commonly craniopharyngioma), granulomatous diseases such as Langerhans cell histiocytosis and sarcoidosis, trauma from neurosurgery or accidents, inflammatory and autoimmune diseases such as lymphocytic infundibulo-hypophysitis. In up to 50% of patients, particularly children and young adults the etiology of DI remains unknown and in such cases DI is termed idiopathic (2).
Magnetic resonance imaging (MRI) is the best and the most precise method for imaging the pituitary gland and hypothalamus and the endocrine diseases originating in that region (3). MR images of the pituitary gland show not only detailed anatomy of anterior and posterior pituitary lobes (adenohypophysis and neurohypophysis), pituitary stalk and infundibulum but they allow to conclude on the posterior pituitary function as well. The normal content of vasopressin packed in neurosecretory granules and stored in neurohypophysis is responsible for the high signal intensity of the posterior pituitary gland in pre-contrast T1-weighted MR images (4). Therefore, in most cases of normal posterior pituitary function the hyperintense signal in the posterior part of the sella turcica is present (called posterior pituitary bright spot). On the other hand, in most cases of central diabetes insipidus the bright spot is absent (5).
The aim of the study was to retrospectively review the cases of the central diabetes insipidus among the patients hospitalized at the Department of Endocrinology of The Centre of Postgraduate Medical Education in Bielański Hospital during last year. We evaluated the prevalence and causes of the disease, with a detailed analysis of the magnetic resonance imaging of the pituitary-hypothalamic region results.
Material and methods
We retrospectively reviewed the electronic medical records of patients hospitalized at the Department of Endocrinology in Bielański Hospital during last year (between September 2012 and September 2013) searching for the patients with the ICD-10 codes: D35.2 (benign neoplasm of pituitary gland) and E23. That included patients with following codes: E23.0 (hypopituitarism), E23.1 (iatrogenic hypopituitarism), E23.2 (diabetes insipidus), E23.6 (other disorders of pituitary gland). We searched electronic and paper documentation of those patients (n = 300) to find the cases with the diagnosis of diabetes insipidus (DI). Then, in that selected group of patients (n = 37) we collected data on the age, sex, causes of DI, disease duration, results of hormonal and biochemic tests and applied treatment. The results of current magnetic resonance imaging of pituitary-hypothalamic region, available in 32 cases, were analysed. We investigated the presence or absence of posterior pituitary bright spot on pre-contrast T1-weighted sagittal MR images, we looked for sellar or parasellar tumours and estimated the pituitary height and pituitary stalk thickness.
Additionally we analysed the presence or absence of the posterior pituitary hyperintensity on the MRI scans performed in 38 consecutive patients admitted to the Department of Endocrinology with no symptoms of diabetes insipidus.
During last year (from September 2012 to September 2013) one thousand seven hundred twenty four (1724) patients with numerous endocrine disorders were hospitalized at the Department of Endocrinology in Bielański Hospital. Among them 37 patients had the diagnosis of diabetes insipidus, which was 2.15% of all hospitalized patients in the Department of Endocrinology. The mean age was 43.2 ± 17.1 years (range from 18 to 80 years). There were 25 (67.6%) females and 12 (32.4%) males. Only nine patients with DI (24.3% of DI patients and 0.5% of all patients) have been hospitalized because of the symptoms of DI that had appeared recently (less than half a year before hospitalization) and the new diagnosis of DI has been established or the suspicion has been confirmed in all but one patient. Diagnoses in most cases were based on symptoms (hypotonic polyuria and polydipsia > 4 liters/24 h) and decreased urine osmolality, that resolved following desmopressin administration, if diabetes mellitus, hypercalcemia, hypokaliemia and renal disease were excluded.
Majority of patients (75.7% of DI patients) had well controlled permanent diabetes insipidus that lasted for years (on average for 7 years, approximately) and the reason for hospitalization was to assess the progress of the underlying disease and to control efficiency of treatment. Duration of the disease varied from couple of weeks to 21 years; between half a year and one year in four patients, between one year and five years in six patients, between five and ten years in three patients, between ten and twenty years in ten patients and longer than twenty years in three patients. One patient had transient postoperative DI that resolved in 3 months, and a patient with gestational diabetes insipidus had a spontaneous remission after delivery.
Twenty five patients with DI (67.6%) had pituitary insufficiency. Among them majority of patients (n = 18) had panhypopituitarism; in 16 patients as a result of pituitary-hypothalamic tumours or past surgery, in one case with limfocytic hypophysitis and in one case with metastatic pituitary lesion. In 7 patients we observed partial deficiency of pituitary hormones: adrenocorticotropic hormone (ACTH) in 3 cases, thyrotropin (TSH) and gonadotropins (FSH and LH) in 2 cases and gonadotropins only in 2 cases. There were 11 patients with normal function of anterior lobe of the pituitary gland. In the group with normal adenohypophysis function there were patients with posttraumatic, idiopathic and gestational DI, patients with encephalitis and meningitis in anamneses, one case of histiocytosis and one patient after two operations of a large sellar tumour.
Seven patients had various visual disturbances following craniotomy for large suprasellar tumours: visual field defects, diplopia and even blindness.
Etiology of diabetes insipidus
The causes of DI in studied group are listed in table 1. In almost two-thirds of our patients, diabetes insipidus was the consequence of prior surgery of the pituitary-hypothalamic tumours or the presence of the tumour itself. The most frequent type of tumours in our group were pituitary adenomas (in 9 cases, 24.3%) but in all these cases the DI was a complication of the surgical treatment not the tumour itself. Similarly, diabetes insipidus appeared usually postoperatively in other patients with pituitary-hypothalamic tumours such as craniopharyngiomas, Rathke’s cleft cysts, meningioma and other not classified tumours, although we had not precise data on the time of DI appearance in each case. Diabetes insipidus was one of the first symptoms of the disease in one patient with Rathke’s cleft cyst and in another with pituitary metastatic lesion.
Table 1. Etiology of diabetes insipidus in 37 patients hospitalized in the Department of Endocrinology between September 2012 and September 2013 with recognized previously central diabetes insipidus (n = 28) or new onset of polydipsia/polyuria syndrome (n = 9).
|Causes of diabetes insipidus||Number of patients||Frequency (%)|
|Pituitary/hypothalamic tumours||Pituitary adenoma||9||24.4|
|Rathke’s cleft cysts||2||5.4|
|Langerhans cell histiocytosis||2||5.4|
|Primary empty sella syndrome ||1||2.7|
|Primary polidypsia (psychogenic)||1||2.7|
Only one third of the studied group suffered from DI not related to the sellar or suprasellar tumours. We found two cases of Langerhans cell histiocytosis, two lymphocytic hypophysites, two posttraumatic and two post-inflammatory DI (meningitis and encephalitis in anamneses). In single cases we identified gestational DI and DI caused by primary empty sella syndrome (PESS). In two patients the cause of the disease remained unknown (diagnosed as idiopathic DI) and in one patient we excluded central DI and diagnosed primary psychogenic polydipsia.
Treatment and disease control
All patients but one with primary psychogenic polydipsia, have been treated with vasopressin analogue – desmopressin (DDAVP) and data on doses used were available for 33 patients. Twenty five patients have been treated with sublingual tablets (Minirin MELT) with the mean daily dose approximately 150 mcg (range from 30 to 480 mcg, 1 to 4 times per day). Eight patients have been taking desmopressin nasally (Minirin) in doses ranging from 10 to 40 mcg daily (mean 23.75 ug, once or twice a day).
In five patients sodium concentration imbalances were present. We observed mild hyponatremia in 3 cases – (Na+): 131-133 mEq/L, moderate in one case – (Na+) = 129 mEq/L, and severe in one case – (Na+) = 121 mEq/L. In two later cases hyponatremia was corrected by reducing desmopressin dose and improving the control of secondary adrenal insufficiency. In the hospitalized group mean sodium concentration (Na+) was 138.3 ± 4.2 mEq/L and mean potassium concentration (K+) was 4.2 ± 0.4 mEq/L.
Magnetic Resonance Imaging results
MRI of pituitary-hypothalamic region was available for evaluation in 32 cases. The posterior pituitary bright spot on T1-weighted images was absent in all but two cases: one patient with psychogenic polydipsia and one patient with transient DI following transsphenoidal surgery for a large inactive adenoma who was examined 3 months after operation when DI symptoms resolved. Another patient with posttraumatic DI had some residual hyperintesity of the posterior pituitary present on the MR images performed 3 days after traffic accident, although he had persistent DI during our evaluation a month afterward. We did not repeat the MR scan then.
Powyżej zamieściliśmy fragment artykułu, do którego możesz uzyskać pełny dostęp.
Płatny dostęp tylko do jednego, POWYŻSZEGO artykułu w Czytelni Medycznej
(uzyskany kod musi być wprowadzony na stronie artykułu, do którego został wykupiony)
Płatny dostęp do wszystkich zasobów Czytelni Medycznej