Amplitude of low-frequency fluctuations on Alzheimer’s disease with depression: evidence from resting-state fMRI

BACKGROUND: The prevalence of Alzheimer’s disease (AD) comorbid with depression is common. However, the mechanisms of AD with depression remain unclear. AIMS: To investigate the regional alterations of brain activity of AD with depression in resting-state functional magnetic resonance imaging (rs-fMRI). METHODS: 154 patients with AD who met the inclusion criteria were recruited from the Zhejiang Provincial People’s Hospital from October 2014 to October 2016. According to whether the core symptoms of depression were present, patients were divided into two groups, 22 patients with AD with depression (AD-D) and 52 patients with AD without depression (AD-nD). The amplitude of low frequency fluctuations (ALFF) was compared between two groups by performing independent-samples t-test. RESULTS: Compared with the AD-D group, increased ALFF values in the bilateral superior frontal gyrus, left middle frontal gyrus and left inferior frontal gyrus were observed in the AD-nD group. The brain activity in the AD-nD group in the bilateral superior frontal gyrus, left middle frontal gyrus and the left inferior frontal gyrus was higher than the AD-D group. CONCLUSIONS: Resting-state brain functional alterations may be closely bound up with the pathophysiologic features of patients with AD with depressive symptoms.