Cognitive dysfunction in acromegaly: a clinical study in 55 patients

Background: Pleiotropic effects of GH and IGF-1 on the brain have been described. We recently reported an increase in grey and white matter volumes in acromegalic patients as well as elevated rates for mental disorders such as dysthymia and depression. However, it is not clear whether acromegalic patients also suffer from cognitive dysfunction. Objective: To determine if cognitive impairments in patients with acromegaly exist, which domains are affected, and whether such impairments are associated with psychopathologic symptoms, and biochemical and MRI-abnormalities. Design and Setting: This is a clinical cross-sectional study conducted at the Endocrine Outpatient Unit of the Max Planck Institute of Psychiatry in cooperation with the Department of Internal Medicine of the Ludwig Maximilians University in Munich, Germany. Patients: Between April 2006 and September 2007, 55 patients with biochemically confirmed acromegaly aged 18 years and older were enrolled. Main outcome measures: Main outcome measures were percentage ranks in speed of information processing, attention, verbal memory and verbal fluency, and visual problem solving. A percentage rank of <16% of normal performance was considered as cut off value.

Results: Between 37 and 67.3% of patients failed to reach the level of normal performance in at least one cognitive test, with the highest percentages in attention (information processing speed) and long-term verbal memory. Conclusion: Cognitive impairments mainly in the domains of information processing/attention, verbal memory and executive function were present in our acromegalic patient sample indicating dysfunction in multiple cognitive domains. Thus, neuropsychological testing should be part of the comprehensive diagnostic assessment of these patients both before and after hormone substitution and therapy.