ABSTRACT
Objective To investigate the morphological changes of the brainstem in patients with Alzheimer's disease (AD) and their relationship with hippocampal morphological changes.Methods Sixty AD patients (AD group) and sixty age-and gender-matched normal elderly (normal control group) were selected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database.The hippocampus and the brainstem of each subject were segmented and their normalized volumes were calculated.According to the hippocampal volume standard value (Z-score),AD patients were divided into two subgroups (hippocampal atrophy group (n=51) and hippocampal spared group (n=9)).A voxel-based morphology (VBM) study was also performed to investigate the morphological differences of the brainstem between the normal control group and the AD group,as well as between the AD subgroups.Results Compared with the normal control group,the brainstem volume in the AD group decreased significantly (16 741.31±1 739.11 vs 15 609.67±1 451.60,t=3.870,P=0.001).In AD subgroups,the volume of the brainstem in the hippocampal atrophy group was significantly smaller than that in the hippocampal spared group (16 556.30 ± 1 514.86 vs 15 442.62 ± 1 389.05,t=2.189,P=0.033).Pearson correlation analysis showed that Mini-Mental State Examination scores were positively correlated with the hippocampal and the brainstem volumes (r=0.590,P＜0.01;r=0.234,P＜0.05),and there was a positive correlation between the hippocampal and the brainstem volume changes in patients with AD (r=0.315,P=0.014).VBM results showed that both the bilateral midbrain and the bilateral pons in the AD group had significant atrophy compared with the normal control group (P＜0.05).In the AD subgroups,the bilateral midbrain and the left pons in the hippocampal atrophy group were significantly atrophied compared with the hippocampal spared group (P＜0.05).Conclusion The brainstem showed morphological changes in patients with AD,and the morphological changes of the brainstem in AD patients with different degrees of hippocampal atrophy were different,indicating the morphological changes of the hippocampus and the brainstem may have an interrelated relationship.