Glymphatic System Dysfunction and Altered Brain Connectivity in Medication Overuse Headache: A 7-Tesla MRI Study

Motivation: The glymphatic system (GS) and brain function are involoved in Medication overuse headache (MOH) pathophysiology. Goal(s): To investigate differences in GS and brain function in MOH versus episodic migraine (EM) and healthy controls (HCs), and correlations between GS, brain function, and clinical parameters in MOH. Approach: We evaluated the analysis along the perivascular space (ALPS) index, mean amplitude of low-frequency fluctuations (mALFF) and regional homogeneity (Reho) in 49 MOH patients, 54 EM patients, and 45 HCs using 7T. Results: MOH patients showed a lower ALPS index, higher mALFF, and altered FC, with ALPS index correlating with FC, pain degree, and duration in MOH. Impact: The ALPS index and functional changes may serve as a sensitive neuroimaging biomarker for predicting the progression from EM to MOH. And they may interact with each other in the pathogenesis of patients with MOH, collectively influencing the disease mechanism.