Evaluation of the glymphatic system in patients with bipolar disorder using the DTI-ALPS method

Motivation: Our previous study revealed abnormalities in aquaporin 4, which works at the cerebrospinal–interstitial fluid exchange in the postmortem brains of patients with bipolar disorder (BP). However, glymphatic system (GS) alterations in BP are still unclear. Goal(s): This study aims to assess GS function in BP patients. Approach: We used diffusion tensor image analysis along the perivascular space (DTI–ALPS) method in BP subjects and healthy controls (HCs). Results: The ALPS index of BP subjects was significantly lower than that of HCs. We also found associations between the ALPS index and BP risk. Thus, per our findings, BP patients could have GS dysfunction. Impact: This study suggests the potential for GS dysfunction in BP patients. Our findings could support the fact that BP patients are more likely to experience dementia since they have an Alzheimer’s disease-like pathology that causes amyloid β accumulation.