Effects of Growth Hormone Substitution Therapy on Cognitive Functioning in Growth Hormone Deficient Patients: A Functional MRI Study

Vol. 83, No. 1, 2006

Free Abstract Article (Fulltext) Article (PDF 266 KB)

Original Paper

Effects of Growth Hormone Substitution Therapy on Cognitive Functioning in Growth Hormone Deficient Patients: A Functional MRI Study
Lucia I. Arwert^a, Dick J. Veltman^b, Jan Berend Deijen^c, P. Sytze van Dam^d, Madeleine L. Drent^a

^aDepartment of Endocrinology and
^bPET Center, VU University Medical Center, and
^cDepartment of Clinical Neuropsychology, Free University, Amsterdam, and
^dDepartment of Endocrinology, University Medical Center Utrecht, Utrecht, The Netherlands

Address of Corresponding Author

Neuroendocrinology 2006;83:12-19 (DOI: 10.1159/000093337)

Key Words

Growth hormone deficiency
Insulin-like growth factor I
Functional magnetic resonance imaging
Working memory
Cognition
Mood

Abstract

Patients with childhood-onset growth hormone (GH) deficiency (GHD) show impairments in mood and cognitive functioning which may resolve following GH substitution. Brain functional magnetic resonance imaging (fMRI) during performance of a memory task was used to assess the cerebral activity of such patients. Thirteen childhood-onset GHD patients (mean age 27.3 ± 6.9 years) were included in a double-blind, placebo-controlled study. The effects of 6 months of GH replacement or placebo therapy were studied using neuropsychological tests and fMRI. One patient was excluded from the study due to noncompliance with the protocol. Six months of GH substitution in these GHD patients resulted in improved memory functioning, both for long-term and working memory. fMRI showed activations during the working memory task in prefrontal, parietal, motor, and occipital cortices, as well as in the right thalamus and anterior cingulate cortex. Decreased activation in the ventrolateral prefrontal cortex was observed after GH treatment as compared with placebo treatment, indicating decreased effort and more efficient recruitment of the neural system involved. It can be concluded that GH treatment for 6 months improved the long-term as well as the working memory in patients with GHD, and this was associated with decreased brain activation in the ventrolateral prefrontal cortex. GH substitution in GHD patients is beneficial for cognitive functioning, the effects of which can be visualized by means of neuroimaging.

Author Contacts

Lucia I. Arwert
Department of Endocrinology, VU University Medical Center
PO Box 7057
NL-1007 MB Amsterdam (The Netherlands)
Tel. +31 20 444 2799, Fax +31 20 444 0502, E-Mail l.arwert@vumc.nl

Article Information

Received: January 23, 2006
Accepted after revision: April 13, 2006
Published online: May 15, 2006
Number of Print Pages : 8
Number of Figures : 4, Number of Tables : 3, Number of References : 35

Medline Abstract (ID 16707911)

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