Third nerve palsy with contralateral ocular torsion and binocular tilt of visual vertical, indicating a midbrain lesion

Abstract

The authors describe the case of a 77-year-old diabetic woman presenting with acute and painful onset of an ‘isolated’ pupil-sparing left-sided third nerve palsy which was suggestive for a diabetic mononeuropathy. Neuro-ophthalmologic investigation including measurements of ocular torsion and perception of verticality showed involvement of both eyes with binocular tilts to the contralateral right side thereby indicating a left-sided midbrain lesion which included the fascicle of the third nerve as well as supranuclear integration centers for torsional eye movements, the interstitial nucleus of Cajal, and the rostral interstitial nucleus of the medial longitudinal fasciculus. MRI confirmed a paramedian rostral midbrain infarction most likely caused by biopsy-proven giant cell arteritis.

Key Words:

• Third nerve palsy
• midbrain infarction
• giant cell arteritis