Wallerian degeneration
Pronunciation: wall-EER-ee-an
Anterograde degeneration of axons and myelin sheaths distal to a site of injury, visible on advanced MRI.
Full Definition
Wallerian degeneration is a well-characterized process of anterograde axonal degeneration that occurs distal to the site of axonal injury or cell body death. In neuroimaging, this process can be detected using diffusion tensor imaging, which shows decreased fractional anisotropy and increased mean diffusivity in affected white matter tracts weeks to months after the initial insult. Common causes include stroke, traumatic brain injury, or surgical intervention. Understanding this process is important for predicting long-term functional outcomes and monitoring disease progression.
Usage
Usage note: Specify timing relative to initial injury; distinguish from other degenerative processes.
In Context
- "DTI revealed evidence of Wallerian degeneration in the corticospinal tract three months post-stroke." — Follow-up diffusion tensor imaging report
- "The pattern of signal change was consistent with Wallerian degeneration rather than primary demyelination." — Advanced imaging interpretation