Aberrant Regeneration of the 3rd Nerve

Aberrant regeneration in two patients: 1) a young woman with a right cavernous sinus meningioma with subsequent development of aberrant regeneration demonstrated by eyelid elevation OD in attempted downgaze (i.e., some fibers that were supposed to innervate the right IR were misrouted to the right levator), and 2) a woman with a traumatic 3rd nerve palsy OS demonstrating two features of aberrant regeneration - a. LID - eyelid elevation OS in adduction and depression (i.e., some fibers that were supposed to innervate the left IR and MR were misrouted to the left levator), and b. MOTILITY - adduction OS with attempted upward and downward saccades (i.e., some fibers that were supposed to innervate the left SR and IR were misrouted to the left MR). These findings were particularly apparent when using an optokinetic stimulus. Aberrant regeneration of the 3rd nerve should raise one's suspicion for a mass lesion (e.g., PCOM aneurysm, meningioma) or can be seen post-trauma. It does NOT occur following a vasculopathic injury. Video shows two cases of aberrant regeneration demonstrating involvement of the eyelid and motility.