Impaired glymphatic system for upper limb motor dysfunction in patients with acute ischemic stroke

Area of Science:

• Neuroscience
• Medical Imaging
• Cerebrovascular Disease Research

Background:

• Acute ischemic stroke (AIS) impairs brain perfusion and waste clearance, potentially affecting the glymphatic system.
• Investigating glymphatic activity is crucial for understanding stroke pathophysiology and recovery.
• The diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) method offers a way to assess glymphatic function.

Purpose of the Study:

• To evaluate glymphatic activity in AIS patients using the DTI-ALPS method.
• To correlate glymphatic function with upper limb motor deficits in AIS.
• To identify factors associated with changes in glymphatic activity post-stroke.

Main Methods:

• Prospective enrollment of 59 AIS patients and 29 healthy controls (HCs).
• Assessment of glymphatic function using the ALPS index derived from DTI-ALPS.
• Correlation analysis between ALPS index and clinical variables (FMA-UE, NIHSS, time since onset, infarct volume).
• Follow-up MRI scans for 18 patients to assess changes in ALPS index over 2 months.

Main Results:

• AIS patients exhibited significantly lower ALPS index values in both ipsilateral and contralateral hemispheres compared to HCs.
• The ALPS index positively correlated with upper limb motor function (FMA-UE) and negatively with stroke severity (NIHSS).
• A significant increase in ALPS index was observed from baseline to 2-month follow-up in AIS patients.

Conclusions:

• Reduced ALPS index in AIS patients signifies impaired glymphatic function, linked to upper limb motor dysfunction.
• The ALPS index is associated with stroke severity and may serve as a neuroimaging biomarker.
• Glymphatic function shows potential for recovery in AIS patients within 2 months post-stroke.