Differential glymphatic dysfunction and memory correlation in temporal lobe epilepsy subtypes.

Area of Science:

• Neuroimaging
• Epilepsy Research
• Cerebrovascular Biology

Background:

• The glymphatic system (GS) facilitates waste clearance in the brain.
• Dysfunction of the GS is implicated in various neurological disorders.
• Temporal lobe epilepsy (TLE) is often associated with cognitive deficits, particularly memory impairment.

Purpose of the Study:

• To evaluate glymphatic system (GS) function in different temporal lobe epilepsy (TLE) subtypes using diffusion tensor imaging analysis along the perivascular space (DTI-ALPS).
• To explore the correlation between GS function, clinical factors, and memory performance in TLE patients.

Main Methods:

• Diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) was performed on 112 TLE patients with hippocampal sclerosis (TLE-HS), 73 TLE patients with no lesions (TLE-NL), and 55 healthy controls.
• Memory performance was assessed using the Wechsler Memory Scale-Revised.
• Statistical analyses compared DTI-ALPS indices among groups and explored relationships with clinical data and memory outcomes.

Main Results:

• The TLE-HS group showed significantly lower DTI-ALPS indices in both hemispheres compared to controls.
• The TLE-NL group exhibited reduced DTI-ALPS indices in the ipsilateral hemisphere only.
• In TLE-HS patients, the DTI-ALPS index positively correlated with memory performance, and was a significant predictor of memory quotient.
• Focal to bilateral tonic-clonic seizures in TLE-NL were associated with reduced DTI-ALPS indices in both hemispheres.

Conclusions:

• Distinct patterns of glymphatic system impairment exist between TLE-HS and TLE-NL.
• Glymphatic dysfunction is associated with memory deficits in TLE, particularly in TLE-HS.
• Targeting the glymphatic system may offer a novel therapeutic strategy for memory enhancement in epilepsy.