The pituitary stalk interruption syndrome: endocrine features and benefits of growth hormone therapy

Childhood anterior-pituitary insufficiency has many causes (malformative, genetic, traumatic, tumoral...). One particular entity can be clearly identified: pituitary stalk interruption syndrome (PSIS). The aim of our study was to analyse the long-term evolution of patients with PSIS.

The records of all the children followed at Dijon University Hospital between 1990 and 2008 who underwent brain magnetic resonance imaging (MRI) and endocrinological evaluation that revealed a growth hormone (GH) deficiency were analysed. We thus selected 14 children diagnosed with PSIS according to the results of MRI. We studied the perinatal characteristics of these patients, then the auxological and the endocrine evolutions, before the initiation of GH therapy and then after 1 and 3 years of treatment and during the last evaluation.

Fourteen children were diagnosed with PSIS at a mean+/-sd age of 3.2+/-3.5 years, five of whom being diagnosed during the first 2 months of life. Growth, as well as other anterior-pituitary deficiencies, was systematically followed up two to four times a year depending on the clinical context. The results in terms of endocrinology were analysed in all 14 children, and with regard to auxology in the 10 children who received GH therapy for at least 12 months, with a mean of 8.3+/-4.2 years and at a mean maintenance posology of 0.22+/-0.02mg/kg per week. Among the 14 children, 12 had complete GH deficiency while two had a partial deficiency. Nine had multiple anterior pituitary deficiencies, diagnosed at the same time or later in five and four of them respectively. A clinical picture of panhypopituitarism was found in the infants who were diagnosed with PSIS in their first months of life. In the 10 children who were treated for at least 12 months, the height before treatment was -3.1+/-0.8 standard deviation score (SDS). At the last consultation, the total gain in height was +2.5+/-0.9 SDS compared to the distance to target height of +2.7+/-0.6 SDS. The height gain after 1 year of treatment corresponded to 60% of the total gain.

In children with PSIS, the other anterior pituitary deficiencies are often associated with GH deficiency and sometimes during the first month of life. These functions therefore require to be carefully followed early, periodically and in the long term. Growth in these children responds particularly well to GH therapy, in particular during the first year.