Wallerian degeneration of the middle cerebellar peduncles secondary to pontine infarction, case report, and review of literature

Wallerian degeneration (WD) is a process of axonal degradation that occurs downstream from a primary injury site and is often seen after strokes affecting the brainstem. This case report documents WD of the bilateral middle cerebellar peduncles (MCPs) in an 81-year-old woman following chronic left paramedian pontine infarction (PPI). An ischemic stroke affecting the pons can trigger downstream axonal degeneration, known as Wallerian degeneration, which involves the structural breakdown of axons distal to the injury site. In this patient, magnetic resonance imaging (MRI) revealed symmetrically increased T2 signal intensity in the MCPs, indicative of WD associated with a known PPI. Although uncommon, it is essential to recognize WD in this location to distinguish it from new ischemic lesions. While the WD of MCPs has not been strongly linked to specific deficits, this phenomenon advances our understanding of the secondary effects of pontine strokes (PS). Detailed documentation of such cases helps improve diagnostic accuracy and prevents misinterpretation of expected postinfarct changes in neuroimaging. This report provides a valuable example of increasing awareness of WD involving MCPs due to PPI.