Eugenio Genovese

Central diabetes insipidus in children and young adults

BACKGROUND Central diabetes insipidus is rare in children and young adults, and up to 50 percent of cases are idiopathic. The clinical presentation and the long-term course of this disorder are largely undefined. METHODS We studied all 79 patients with central diabetes insipidus who were seen at four pediatric endocrinology units between 1970 and 1996. There were 37 male and 42 female patients whose median age at diagnosis was 7.0 years (range, 0.1 to 24.8). All patients underwent magnetic resonance imaging (MRI) and periodic studies of anterior pituitary function. The median duration of follow-up was 7.6 years (range, 1.6 to 26.2). RESULTS The causes of the central diabetes insipidus were Langerhans-cell histiocytosis in 12 patients, an intracranial tumor in 18 patients, a skull fracture in 2 patients, and autoimmune polyendocrinopathy in 1 patient; 5 patients had familial disease. The cause was considered to be idiopathic in 41 patients (52 percent). In 74 patients (94 percent) the posterior pituitary was not hyperintense on the first MRI scan obtained, and 29 patients (37 percent) had thickening of the pituitary stalk. Eighteen patients had changes in the thickness of the pituitary stalk over time, ranging from normalization (six patients) or a decrease in thickness (one patient) to further thickening (seven patients) or thickening of a previously normal stalk (four patients). Anterior pituitary hormone deficiencies, primarily growth hormone deficiency, were documented in 48 patients (61 percent) a median of 0.6 year (range, 0.1 to 18.0) after the onset of central diabetes insipidus. CONCLUSIONS Most children and young adults with acquired central diabetes insipidus have abnormal findings on MRI scans of the head, which may change over time, and at least half have anterior pituitary hormone deficiencies during follow-up.

Dynamic MRI in the congenital agenesis of the neural pituitary stalk syndrome: the role of the vascular pituitary stalk in predicting residual anterior pituitary function

OBJECTIVE Magnetic resonance imaging (MRI) without contrast medium is unable to give detailed information on the hypothalamic‐pituitary structures. MRI using gadopentetate dimeglumine (Gd‐DTPA), and dynamic MRI, were performed in patients with hypopituitarism previously diagnosed as having anterior pituitary hypoplasia, ectopic posterior pituitary and unidentified pituitary stalk (1) to determine whether Gd‐DTPA improves the delineation of hypothalamic‐pituitary structures; (2) to verify whether, if so, such improvement can be correlated with residual pituitary function in patients subjected to long‐term follow‐up; and (3) to identify the hypothalamic‐pituitary vascular network in such cases.

Role of magnetic resonance imaging in the diagnosis and prognosis of growth hormone deficiency

OBJECTIVE In patients with congenital GH deficiency (GHD), magnetic resonance Imaging (MRI) has revealed morphological abnormalities such as pituitary hypoplasia, absence of the stalk and ectopia of the posterior pituitary (PPE). Our study was aimed at investigating the possible relationship between neuroradioiogical Images and the presence of Isolated GH or multiple pituitary hormone deficiency.

Hypothalamic-pituitary vascularization in pituitary stalk transection syndrome: is the pituitary stalk really transected? The role of gadolinium-DTPA with spin-echo T1 imaging and turbo-FLASH technique.

Abstract We examined 14 patients, aged 10–25 years, with idiopathic hypopituitarism. All presented an ectopic posterior pituitary at the median eminence with a hypoplastic anterior pituitary on magnetic resonance imaging (MRI). Eight patients had isolated growth hormone deficit (IGHD) and six had multiple hormone deficits (MPHD). Unenhanced MRI showed the pituitary stalk, which was extremely thin, in only three patients, while T1-weighted images obtained after intravenous injection of gadopentetate dimeglumine (Gd-DTPA) showed a thin pituitary stalk in seven patients (six with IGHD and one with MPHD), demonstrating a preserved vascular component of the stalk. MRI with Gd-DTPA was more sensitive than unenhanced MRI in detecting the pituitary stalk in patients with hypopituitarism with an ectopic posterior pituitary: the stalk was demonstrated in 50 % of the cases (seven patients), versus 21.4 % (three patients) by unenhanced MRI. The dynamic study of the hypothalamo-hypophyseal axis performed with turbo-FLASH sequences after bolus injection of Gd-DTPA showed the residual anterior pituitary to have arterial enhancement times, which suggests that an arterial system compensates for the absent or diminished blood supply from the portal system, independent of stalk detection.

Central nervous system hyperintensity on magnetic resonance imaging in children with cholestatic liver disease.

Sir: Ballauff et al. [1] described three children with chronic liver disease of different aetiology without hepatic encephalopathy in whom MRI revealed bilateral and symmetrical hyperintensity of the globus pallidus in T~-weighted images. Two patients had an inflammatory liver disease of autoimmune aetiology and one a cryptogenic cirrhosis. The hyperintensity seems to correlate with neither the duration of the liver disease nor the activity, since the serum aminotransferase level was within the normal range in two of the three children. In the patient with auto-immune hepatitis with circulating anti-liver-kidney microsomal antibody, a complete regression of CNS hyperintensity was documented 8 months after the start of an immunosuppressive therapy while in complete remission. We recently observed two patients with a chronic cholestatic disorder and MRI hyperintensity of the basal ganglia; one also showed hyperintensity in the pituitary gland. The first patient is a 15-year-old girl with sclerosing cholangitis and biliary cirrhosis in the context of a Langerhans cell histiocytosis. Biliary cirrhosis was diagnosed at age 6. First MRI performed at age 10 because of central diabetes insipidus evidenced absence of a posterior pituitary bright spot and a thick pituitary stalk with no other pathological findings. MRI follow-up 2 years later, at age 12, revealed normalisation of pituitary stalk size and hyperintensity of both pituitary gland and basal ganglia. In 1994 the hyperintensity of the pituitary gland was still present while the signal of the basal ganglia was increased (Fig. 1). Anterior pituitary function was conserved. Neurological examination and school performance were normal. Liver function evaluation showed a total bilirubin level of 5.5 mg/dl with 3.2 mg/dl of conjugated bilirubin, alanine aminotransferase activity was 4 times the upper limit of normal, y-glutamyl transFig.1 a Sagittal section of hypothalamicpituitary MRI T~-weighted image of patient 1 with sclerosing cholangitis. The hyperintensity involves the whole pituitary gland (arrow). b Coronal section of MRI brain of the same patient revealing bilateral hyperintensity of the basal ganglia (arrows)