Glymphatic dysfunction in trigeminal neuralgia: A multimodal MRI study.

Area of Science:

• Neuroscience
• Radiology
• Biomedical Engineering

Background:

• Trigeminal neuralgia (TN) traditionally linked to peripheral neurovascular compression.
• Emerging evidence suggests central mechanisms play a role in TN pathogenesis.
• Investigating glymphatic system function in TN is crucial for understanding disease mechanisms.

Purpose of the Study:

• To investigate glymphatic system dysfunction in patients with classical trigeminal neuralgia (TN).
• To assess the contribution of glymphatic system impairment to TN pathophysiology.
• To explore the relationship between glymphatic function and clinical features of TN.

Main Methods:

• Cross-sectional study of 71 TN patients and 52 healthy controls.
• Multimodal MRI including diffusion tensor imaging along perivascular spaces (DTI-ALPS) and free water fraction (FWF) mapping.
• Deep learning segmentation for choroid plexus (CP) volumetry and perivascular space (PVS) burden quantification.

Main Results:

• TN patients showed reduced DTI-ALPS indices and increased FWF, indicating glymphatic dysfunction.
• No significant differences in PVS burden or CP volumes between TN patients and controls.
• Glymphatic dysfunction correlated with age, but not with pain intensity or disease duration.

Conclusions:

• Trigeminal neuralgia is associated with functional glymphatic system impairment.
• The findings highlight a dissociation between functional and structural glymphatic measures in TN.
• This suggests underrecognized central mechanisms contributing to TN pathophysiology.