Conclusion
Our findings suggest that segmental intramyelinic oedema is an early, conspicuous white matter change in CADASIL. Brain white matter intramyelinic oedema is consistently found in patients and mouse models with compromised ion and water homeostasis. These data provide a starting point for novel mechanistic studies to investigate the pathogenesis of SVD-related white matter changes.
Results
The principal cerebral white matter changes in TgPAC-Notch3R169C mice are microvacuoles (≤ 1 μm diameter) in the myelin sheaths associated with focal myelin degradation and occurring in the absence of oligodendrocyte loss. Half the damaged myelin sheaths still contain an apparently intact axon. Clearance of myelin debris appears inefficient, as demonstrated by the significant but mild microglial reaction, with occasional myelin debris either contacted or internalized by microglial cells.