Retrograde Degeneration

**Definition:** Pathologic changes that occur in the axon and cell body of a neuron proximal to an axonal lesion. The process is characterized by central chromatolysis which features flattening and displacement of the nucleus, loss of Nissl bodies, and cellular edema. Central chromatolysis primarily occurs in lower motor neurons.

**Tree numbers:** - C23.550.737.500

**Synonyms:** - Axon Reaction - Axonal Reaction - Nissl Degeneration