The Experts below are selected from a list of 2007 Experts worldwide ranked by ideXlab platform

Juliane Leger - One of the best experts on this subject based on the ideXlab platform.

R Brauner - One of the best experts on this subject based on the ideXlab platform.

Paul Czernichow - One of the best experts on this subject based on the ideXlab platform.

F. Severi - One of the best experts on this subject based on the ideXlab platform.

  • 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
    Clinical Endocrinology, 1996
    Co-Authors: Mohamad Maghnie, A. Villa, L. Spagnolo, R. Campan, Eugenio Annibale Genovese, F. Severi
    Abstract:

    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. PATIENTS Eighteen patients (13 males, 5 females) aged 10–26.4 years with unidentified Pituitary Stalk at first MRI study were evaluated. Eight had isolated GH deficiency (IGHD), and 10 had multiple Pituitary hormone defect (MPHD) with the progression to complete anterior Pituitary deficits seen by the age of 15 years in 8 patients (1 had GH and FSH–LH deficiency and 1 had GH, TSH and FSH–LH deficiency). RESULTS The MRI revealed a very thin Pituitary Stalk in 7 patients (38.8%), 6 with IGHD (75%) and 1 (10%) with MPHD (GH and FSH-LH deficiency), after Gd-DTPA administration. Reassessment of anterior Pituitary function showed that the thyroid, adrenal and gonadal functions were intact in the 6 patients with IGHD and Pituitary Stalk identified by Gd-DTPA as well as in one IGHD patient with no evidence of Pituitary Stalk. In one 10-year-old with IGHD at the time of presentation (6 years) and no Pituitary Stalk seen after Gd-DTPA, subclinical hypothalamic hypothyroidism and suspected hypogonadotropic hypogonadism were documented. Partial ACTH deficiency was recorded In the patient with TSH and FSH–LH deficiency with no Pituitary Stalk. After Gd-DTPA, patients with absent Pituitary Stalk had a risk of developing MPHD 27 times greater than had those with an identified Pituitary Stalk (relative risk r=27, 95% confidence interval 1.9–368.4, Fisher’s exact test P=0.009). Dynamic MR images obtained every 4.6 s revealed rapid enhancement of hypothalamic-Pituitary structures and allowed the determination of the times to initial enhancement of ectopic posterior Pituitary and hypoplastic anterior Pituitary which ranged between 9.2 and 18.4 s, and that of complete anterior Pituitary (32.2–41.4 s). The time to maximum enhancement of anterior Pituitary was significantly longer than in controls (35.5±3.8 s vs 25.2±1.6 s, P<0.0001). CONCLUSIONS MRI with Gd-DTPA proved more sensitive in identifying the vascular component of Pituitary Stalk and added new information about the partial preservation of hypothalamo-hypophyseal portal vessels. The vascular Pituitary Stalk is easily recognized after Gd-DTPA in most IGHD patients, but exceptionally in MPHD; this sheds light on the possible normal course of affected patients. The neural component of the Pituitary Stalk is lacking regardless of whether patients have IGHD or MPHD, indicating that the term congenital agenesis of the neural Pituitary Stalk is more appropriate than Pituitary Stalk interruption. The times to enhancement of ectopic posterior Pituitary and residual anterior Pituitary obtained by the fast-framing MRI technique disclose dynamic changes in regional blood supply which appear direct, arterial and mainly independent of the portal system

  • 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.
    1996
    Co-Authors: Mohamad Maghnie, E. Genovese, A. Villa, L. Spagnolo, R. Campan, F. Severi
    Abstract:

    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.Eighteen patients (13 males, 5 females) aged 10-26.4 years with unidentified Pituitary Stalk at first MRI study were evaluated. Eight had isolated GH deficiency (IGHD), and 10 had multiple Pituitary hormone defect (MPHD) with the progression to complete anterior Pituitary deficits seen by the age of 15 years in 8 patients (1 had GH and FSH-LH deficiency and 1 had GH, TSH and FSH-LH deficiency).The MRI revealed a very thin Pituitary Stalk in 7 patients (38.8\%), 6 with IGHD (75\%) and 1 (10\%) with MPHD (GH and FSH-LH deficiency), after Gd-DTPA administration. Reassessment of anterior Pituitary function showed that the thyroid, adrenal and gonadal functions were intact in the 6 patients with IGHD and Pituitary Stalk identified by Gd-DTPA as well as in one IGHD patient with no evidence of Pituitary Stalk. In one 10-year-old with IGHD at the time of presentation (6 years) and no Pituitary Stalk seen after Gd-DTPA, subclinical hypothalamic hypothyroidism and suspected hypogonadotropic hypogonadism were documented. Partial ACTH deficiency was recorded in the patient with TSH and FSH-LH deficiency with no Pituitary Stalk. After Gd-DTPA, patients with absent Pituitary Stalk had a risk of developing MPHD 27 times greater than had those with an identified Pituitary Stalk (relative risk = 27, 95\% confidence interval 1.9-368.4, Fisher's exact test P = 0.009). Dynamic MR images obtained every 4.6 s revealed rapid enhancement of hypothalamic-Pituitary structures and allowed the determination of the times to initial enhancement of ectopic posterior Pituitary and hypoplastic anterior Pituitary which ranged between 9.2 and 18.4 s, and that of complete anterior Pituitary (32.2-41.4 s). The time to maximum enhancement of anterior Pituitary was significantly longer than in controls (35.5 +/- 3.8 s vs 25.2 +/- 1.6 s, P < 0.0001).MRI with Gd-DTPA proved more sensitive in identifying the vascular component of Pituitary Stalk and added new information about the partial preservation of hypothalamo-hypophyseal portal vessels. The vascular Pituitary Stalk is easily recognized after Gd-DTPA in most IGHD patients, but exceptionally in MPHD; this sheds light on the possible normal course of affected patients. The neural component of the Pituitary Stalk is lacking regardless of whether patients have IGHD or MPHD, indicating that the term congenital agenesis of the neural Pituitary Stalk is more appropriate than Pituitary Stalk interruption. The times to enhancement of ectopic posterior Pituitary and residual anterior Pituitary obtained by the fast-framing MRI technique disclose dynamic changes in regional blood supply which appear direct, arterial and mainly independent of the portal system

Stephanie Chen - One of the best experts on this subject based on the ideXlab platform.

  • growth hormone deficiency with ectopic neurohypophysis anatomical variations and relationship between the visibility of the Pituitary Stalk asserted by magnetic resonance imaging and anterior Pituitary function
    The Journal of Clinical Endocrinology and Metabolism, 1999
    Co-Authors: Stephanie Chen, Juliane Leger, Catherine Garel, Max Hassan, Paul Czernichow
    Abstract:

    In GH-deficient children showing ectopic posterior Pituitary hyperintense signal (EPP), the anatomical details of the Pituitary-hypothalamic region and the relationship between the visibility of the Pituitary Stalk and anterior Pituitary function were studied by magnetic resonance imaging (MRI). The absence or presence of the Pituitary Stalk was recorded by MRI before and after the injection of gadolinium in 25 children with GH deficiency and EPP at the age of 8.7 ± 5.0 yr (16 males and 9 females). Patients were classified into 2 groups according to the presence (group 1; n = 14), or the absence (group 2; n = 11) of Pituitary Stalk visibility after gadolinium injection. Most patients in group 1 (12 of 14) demonstrated isolated GH deficiency, whereas all but 1 patient in group 2 showed multiple anterior Pituitary hormone deficiency. The prevalence of a normally sized adenohypophysis was higher in group 1 than in group 2 (50% vs. 9%; P < 0.05). Although the EPP was found at the median eminence in all group ...

  • growth hormone deficiency with ectopic neurohypophysis anatomical variations and relationship between the visibility of the Pituitary Stalk asserted by magnetic resonance imaging and anterior Pituitary function
    The Journal of Clinical Endocrinology and Metabolism, 1999
    Co-Authors: Stephanie Chen, Juliane Leger, Catherine Garel, Max Hassan, Paul Czernichow
    Abstract:

    In GH-deficient children showing ectopic posterior Pituitary hyperintense signal (EPP), the anatomical details of the Pituitary-hypothalamic region and the relationship between the visibility of the Pituitary Stalk and anterior Pituitary function were studied by magnetic resonance imaging (MRI). The absence or presence of the Pituitary Stalk was recorded by MRI before and after the injection of gadolinium in 25 children with GH deficiency and EPP at the age of 8.7+/-5.0 yr (16 males and 9 females). Patients were classified into 2 groups according to the presence (group 1; n = 14), or the absence (group 2; n = 11) of Pituitary Stalk visibility after gadolinium injection. Most patients in group 1 (12 of 14) demonstrated isolated GH deficiency, whereas all but 1 patient in group 2 showed multiple anterior Pituitary hormone deficiency. The prevalence of a normally sized adenohypophysis was higher in group 1 than in group 2 (50% vs. 9%; P<0.05). Although the EPP was found at the median eminence in all group 2 patients, it was visualized in group 1 at different levels of the Pituitary Stalk in 60% of cases (8 of 14; at the proximal end of the Pituitary Stalk, n = 4; in the middle of the Pituitary Stalk, n = 2; at the distal end of the Pituitary Stalk, n = 2). This demonstrates that the ectopic posterior Pituitary migration abnormality may be complete or partial. In conclusion, although the pathogenesis of GH deficiency with EPP remains unclear, these results suggest that in cases of GH deficiency associated with ectopic posterior Pituitary hyperintense signal, patients with no visible Pituitary Stalk on MRI after gadolinium injection present a more severe form of the disease in childhood associated with multiple anterior Pituitary hormone deficiency, whereas visibility of the Pituitary Stalk is related to isolated GH deficiency. Nevertheless, careful follow-up of these latter patients is necessary, as the natural history of the disease is not established until adulthood.