Glymphatic System Dysfunction and DTI along the Perivascular Space in Traumatic Brain Injury: A Systematic Review and...

Area of Science:

• Neuroscience
• Radiology
• Biomarker Discovery

Background:

• The glymphatic system is crucial for brain homeostasis and waste clearance.
• Traumatic brain injury (TBI) disrupts glymphatic function, necessitating reliable assessment methods.
• Diffusion tensor imaging along the perivascular space (DTI-ALPS) shows promise for quantifying glymphatic dysfunction.

Purpose of the Study:

• To systematically review and quantify differences in DTI-ALPS values between TBI patients and healthy controls (HCs).
• To evaluate the potential of DTI-ALPS as a biomarker for glymphatic impairment post-TBI.

Main Methods:

• A comprehensive literature search was conducted across major databases (PubMed, Embase, Scopus, Web of Science).
• Eleven studies with 694 TBI patients and 503 HCs were included in a random-effects meta-analysis.
• Standardized mean differences (Hedges' g) were calculated, and heterogeneity was assessed using I² statistics.

Main Results:

• DTI-ALPS values were significantly lower in TBI patients compared to HCs (Hedges' g = -0.77).
• A significant long-term decrease in DTI-ALPS values was observed in TBI patients over time.
• No significant correlation was found between DTI-ALPS and age or Glasgow Coma Scale scores.

Conclusions:

• Reduced DTI-ALPS values are a significant indicator of glymphatic impairment following TBI.
• DTI-ALPS shows potential as a biomarker for assessing glymphatic dysfunction, particularly in long-term TBI recovery.
• Methodological standardization and longitudinal studies are crucial for establishing the clinical utility of DTI-ALPS.