Brain Tissue Pulsatility is Increased in Midlife Depression: a Comparative Study Using Ultrasound Tissue Pulsatility Imaging.

Cerebrovascular disease (CVD) is consistently associated with late-life depression but poorly documented in midlife depression. It can be hypothesized that the relatively low sensitivity of conventional neuroimaging techniques does not allow the detection of subtle CVD in midlife depression. We used tissue pulsatility imaging (TPI), a novel ultrasound (US) neuroimaging technique that has demonstrated good sensitivity to detect changes in the pulsatility of small brain volumes, to identify early and subtle changes in brain vascular function in midlife depression. We compared the maximum and mean brain tissue pulsatility (MaxBTP and MeanBTP), as identified by TPI, between three groups of middle-aged females matched for age: patients with depression (n=25), patients with remitted depression (n=24) and community controls (n=25). MRI arterial spin labeling, white matter hyperintensities (WMHs) and transcranial doppler (TCD) were used as control conventional markers for CVD. We found no difference in the MRI and TCD measures among the three groups. In contrast, depressive patients showed an increased BTP related to the mean global brain pulsatility (MeanBTP) and no change related to large vessels (MaxBTP) in comparison with the remitted and control groups. US neuroimaging is a highly accurate method to detect brain pulsatility changes related to cerebrovascular functioning, and TPI identified an increased BTP in midlife depressed patients, suggesting early and subtle vascular impairments in this population at risk for CVD such as stroke or WMHs. Because high pulsatility could represent prodromal cerebrovascular changes that damage the brain over time, this paper provides a potential target for blocking the progression of CVD.