Traumatic 3rd Nerve Palsy with Aberrant Regeneration

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This is a 20-yo-woman who experienced severe head trauma and diplopia upon awakening from a coma several weeks after the injury. She had a partial left 3rd nerve palsy (adduction spared), and when she looked to the right and down, her mildly ptotic lid elevated. Aberrant regeneration of CN 3 occurs mainly with trauma or with compressive lesions (eg, PCOM aneurysm, meningioma). The elevation in right gaze is explained by fibers intended to go to the left MR get misrouted to the left levator, while the elevation in down gaze is explained by fibers intended to go to the left IR get misrouted to the left levator causing levator activation and lid elevation. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This is a 20-year-old woman who suffered a traumatic brain injury and experienced diplopia upon awakening from a coma several weeks after the injury. She had a partial left 3rd nerve palsy (adduction spared), and when she looked to the right and down, her mildly ptotic lid elevated. Aberrant regeneration of CN 3 occurs mainly with trauma or with compressive lesions (e.g., posterior communicating aneurysm, meningioma). The elevation in right gaze is explained by the fact that fbers that originally innervated the lxviii medial rectus get misrouted to the left levator palpebrae, while the elevation in down gaze is explained by the fact that fbers that originally innervated the left inferior rectus get misrouted to the left levator causing levator activation and lid elevation. https://collections.lib.utah.edu/ ark:/87278/s6cc48cg