Microvascular changes associated with epilepsy: A narrative review

Area of Science:

• Neuroscience
• Vascular Biology
• Epilepsy Research

Background:

• The blood-brain barrier (BBB) is crucial for brain function and is known to be compromised in temporal lobe epilepsy (TLE).
• Microvascular alterations are suspected to contribute to the pathophysiology of TLE, but a comprehensive understanding is lacking.

Purpose of the Study:

• To review current knowledge on microvascular changes in epilepsy, integrating clinical and preclinical findings.
• To explore the roles of angiogenesis, barriergenesis, and microcirculatory alterations in epilepsy.
• To highlight the involvement of vascular endothelial growth factor (VEGF) in epilepsy-associated vascular pathology.

Main Methods:

• Review of anatomical studies in rodent epilepsy models and human TLE patient biopsies.
• Analysis of preclinical evidence on seizure-induced angiogenesis and barriergenesis.
• Examination of clinical data on microvascular and BBB changes in TLE.

Main Results:

• Rodent models show increased microvascular density and BBB leakage in epilepsy-affected brain regions.
• Human TLE exhibits decreased afferent vessels, abnormal vessel morphology, and thickened endothelial basement membranes.
• VEGF is implicated in endothelial cell proliferation, barriergenesis imbalance, and subsequent neurovascular decoupling, hypoperfusion, and seizures.

Conclusions:

• Epilepsy, particularly TLE, is characterized by disturbed cerebral microvasculature with a significant role for VEGF.
• Abnormalities in basement membranes, like string vessels, indicate a breakdown in endothelial cell regulation.
• Further patient data is needed to confirm findings from preclinical models and biopsy studies.