Microangiopathy in temporal lobe epilepsy with diffusion MRI alterations and cognitive decline

Area of Science:

• Neurology
• Neuroscience
• Pathology

Background:

• White matter microvascular alterations in temporal lobe epilepsy (TLE) may contribute to neurodegeneration and cognitive impairment.
• Understanding these changes is crucial for managing TLE-associated cognitive decline.

Purpose of the Study:

• To quantify microvascular changes, myelin, axonal, glial, and extracellular-matrix alterations in TLE white matter.
• To correlate these pathological findings with in vivo MRI diffusion measurements and cognitive function.

Main Methods:

• Analysis of surgical resections from 44 TLE patients and controls.
• Quantification of microvascular markers (collagen-4, PDGF-Rβ, SMA), myelin (MAG, PLP), and glial cells (Olig2, Iba1).
• Comparison with pre-operative MRI diffusion data and neuropsychological assessments.

Main Results:

• TLE showed increased arteriolosclerosis, reduced mean vascular size, and increased pericyte coverage compared to controls.
• Reduced myelin and increased glial numbers were observed, particularly in deep white matter.
• Microvascular changes correlated with MRI diffusivity, white matter abnormalities, and cognitive decline, especially increased perivascular space.

Conclusions:

• Acquired microangiopathic changes, including vascular sclerosis and altered small vessel function, are present in TLE.
• These pathological findings correlate with white matter diffusion MRI alterations.
• The observed microvascular changes may underlie cognitive decline in TLE patients.