Glymphatic Dysfunction Reflects Post-Concussion Symptoms: Changes Within 1 Month and After 3 Months

Area of Science:

• Neuroscience
• Radiology
• Neurology

Background:

• Mild traumatic brain injury (mTBI) is common, but its effects on the brain's waste clearance system, the glymphatic system, are not fully understood.
• The progression and variability of glymphatic dysfunction after mTBI require further investigation.

Purpose of the Study:

• To examine glymphatic function using diffusion tensor image analysis along the perivascular space (DTI-ALPS) within one month and at three months post-mTBI.
• To determine if variations in glymphatic function are associated with post-traumatic symptom severity.

Main Methods:

• DTI-ALPS was measured in 39 mTBI patients and 35 controls at baseline and follow-up.
• Linear mixed-effects models analyzed differences in ALPS indices and associations with symptom severity (RPCSQ).
• Patients were subgrouped based on ALPS changes (increasing vs. decreasing) to analyze symptom trajectories.

Main Results:

• Glymphatic function (ALPS index) was not different at baseline but was significantly lower in mTBI patients at follow-up.
• Longitudinal changes in ALPS were significantly associated with symptom severity scores.
• Individuals with decreasing ALPS showed more severe symptoms and slower recovery.

Conclusions:

• Glymphatic dysfunction, indicated by the ALPS index, may be linked to persistent post-traumatic symptoms after mTBI.
• A time-dependent assessment of glymphatic biomarkers, considering individual recovery, is vital for mTBI evaluation.