Altered cerebral perfusion in bipolar disorder: A pCASL MRI study

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Neurovascular abnormalities are implicated in bipolar disorder (BD) pathophysiology.
• Previous cerebral blood flow (CBF) studies in BD are limited and inconclusive.
• Understanding CBF in BD is crucial for assessing brain function.

Purpose of the Study:

• To compare cortical gray matter CBF (GM-CBF) between individuals with BD and healthy controls (HC).
• To investigate the relationship between GM-CBF and cognitive or clinical measures in BD.

Main Methods:

• Cortical GM-CBF maps were generated using Pseudo-Continuous Arterial Spin Labeling (pCASL) in 109 participants (61 BD, 48 HC).
• Non-parametric voxel-wise two-sample t-tests (SnPM13) compared CBF between groups.
• Multiple linear regression analyzed relationships between GM-CBF and clinical/cognitive data, with corrections for multiple comparisons.

Main Results:

• BD patients exhibited increased GM-CBF in the left lateral occipital cortex and decreased CBF in the right occipital, angular, and middle temporal gyri compared to HCs.
• Higher GM-CBF in the left lateral occipital cortex was linked to poorer working memory, verbal memory, attention, and processing speed.
• Decreased thalamic and cerebellar CBF, and increased right fronto-limbic CBF, correlated with impaired working memory.

Conclusions:

• Cortical GM-CBF alterations are evident in bipolar disorder.
• These CBF changes are associated with cognitive impairments.
• Findings suggest neurovascular unit dysfunction as a potential mechanism in BD pathophysiology.