Lianping Zhao1, Ying Wang1, Yanbin Jia1, Shuming Zhong1, Yao Sun1, Zhifeng Zhou1, and Li Huang1,2
Depression in
the context of bipolar disorder (BD) is often misdiagnosed as unipolar
depression (UD), leading to mistreatment and poor clinical outcomes. However,
little is known about the similarities and differences in cerebellum between BD
and UD. Patients with BD (n = 35) and UD (n = 30) during a depressive episode
as well as 40 healthy controls underwent diffusional kurtosis imaging (DKI) and
three dimensional arterial spin labeling (3D ASL). The DKI parameters including
mean kurtosis (MK), axial kurtosis(Ka), radial kurtosis (Kr),fractional
anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da) and radial
diffusivity (Dr) and 3D ASL parameters (i.e. cerebral blood flow) was measured
by using regions-of-interest (ROIs) analysis in the superior cerebellar
peduncles(SCP), middle cerebellar peduncles (MCP) and dentate nuclei (DN) of
cerebellum. Patients with UD exhibited significant differences from controls
for DKI measures in bilateral SCP and MCP and cerebral blood flow (CBF) in
bilateral SCP and left DN. Patients with BD exhibited significant differences
from controls for DKI measures in the right MCP and left DN and CBF in the left
DN. Patients with UD showed significantly lower MD values compared with
patients with BD in the right SCP. Correlation analysis showed there were
negative correlations between illness duration and MD and Dr values in the
right SCP in UD, and negative correlations between illness duration and CBF in
bilateral SCP in BD. Our findings provide new evidence of microstructural
changes in cerebellum in BD and UD. The two disorders may have overlaps in
microstructural abnormality in MCP and DN during the depressive period.
Microstructural abnormality in SCP may be a key neurobiological feature of UD.
