aberrant regeneration
Abnormal regrowth of damaged cranial nerve fibers, resulting in inappropriate innervation and paradoxical eye movements.
Full Definition
Aberrant regeneration occurs when damaged cranial nerve fibers regrow incorrectly, creating inappropriate neural connections. Most commonly seen with third nerve palsies, it manifests as lid elevation with attempted downgaze, pupil constriction with adduction, or globe retraction with vertical eye movements. This phenomenon suggests previous nerve damage rather than acute injury and is pathognomonic for compressive lesions such as aneurysms or tumors. Aberrant regeneration does not occur with microvascular ischemic palsies. Recognition of these signs is crucial for determining etiology and guiding further investigation.
Usage
Usage note: Always document specific patterns of aberrant regeneration as they provide diagnostic clues.
In Context
- "Aberrant regeneration of the third nerve was evident by lid elevation during attempted downgaze." — Clinical examination
- "The presence of aberrant regeneration ruled out diabetic third nerve palsy." — Differential diagnosis