Memory complaints in patients with normal cognition are associated with smaller hippocampal volumes

Abstract

We aimed to investigate volumetry of the medial temporal lobe in patients with subjective memory complaints without any cognitive impairment. This study included 20 patients with subjective memory complaints and normal cognitive function and 28 controls without memory complaints. Volumes of the hippocampus and parahippocampal gyrus (PHG) were measured using coronal T1-weighted MR images. Cognitive functions were assessed using the Cambridge Cognitive Examination. Depressive symptoms were assessed using the Geriatric Depression Scale. Differences between groups were analysed using t-tests. Patients with subjective memory complaints had a higher education and more depressive symptoms than controls ( p < 0.01). Moreover, they had smaller left hippocampal volumes than controls ( p < 0.01). There were no differences between groups in the volume of the right hippocampus or PHG. There was a moderate association between the volume of left hippocampus and left PHG and memory-score (r = 0.32, p = 0.03; r = 0.34, p = 0.02). We concluded that memory complaints in patients without any cognitive impairment were associated with smaller left hippocampal volumes and more depressive symptoms. These preliminary results suggest that memory complaints may reflect minimal brain deficits associated with impending dementia, depression or a combination of both disorders.