Background: In acromegaly, few in vivo data exist on changes of the brain parenchyma as a pathology caused by systemically elevated levels of GH and IGF-1. This is in contrast to neuropsychiatric symptoms such as depression, cognitive impairment, personality changes and pain syndromes that accompany the condition. We aimed at measuring brain tissue volumes and white matter pathology in acromegaly.
Methods: Forty-three patients (age 54±14 years, 54% female, age at diagnosis 46.9±14 years) and age/gender matched, neuropsychiatrically healthy controls (medical comorbidities tolerated) underwent high resolution clinical MRI. Total volumes of grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) were calculated using SPM5. Raw volumes and volumes normalized to total inracranial volume were compared. Focal white matter lesions (WMLs, mainly reflecting gliosis) were rated on fluid attenuated inversion recovery (FLAIR) and T2-weighted images, employing a classification into grades 0: no WMLs, I: 15, II: 620, III: 2140, IV: >40 WMLs.
Results: Patients showed larger absolute (627±79 vs. 604±85 ml, P=0.076) and normalized GM volumes (42.1±2.9% vs. 41.5±3.1%, P=0.099) and WM volumes (460±64 vs. 435±61 ml, P=0.090), and 30.8±29.8%, P=0.043). Absolute and relative CSF was decreased in patients (403±74 vs. 416±70 ml, P=0.029; 27.1±4.2% vs. 28.7±4.5%, P=0.018). The proportion of patients with intact WM was lower (18.6% vs. 39.5%, P=0.028) with most prominent shifts to WML grade I changes (44.2% vs. 30.2%).
Discussion: We provide evidence of increased GM and WM volumes at the expense of CSF in acromegaly. These changes may relate to the chronic exposure to GH and IGF-1 and its trophic effects. The reported WM pathology likely reflects the increased prevalence of vascular and metabolic comorbidities. These changes might contribute to an altered pattern of neuropsychiatric comorbidities in this patient group.
03 - 07 May 2008
European Society of Endocrinology