Isolated Superior Divisional Oculomotor Nerve Palsy and Nystagmus Following Mild Trauma.

Traumatic isolated divisional oculomotor nerve palsy has not been reported following mild head injury. We present an interesting case of a 10-year-old male boy who presented with right-sided ptosis, upgaze palsy, and horizontal nystagmus following a mild head trauma. Magnetic resonance imaging showed right superior rectus muscle atrophy. After observing for 6 months, right inferior rectus recession was done. The abnormal head posture and diplopia got corrected, but nystagmus persisted, although with appreciably decreased amplitude. We here report a rare case of an isolated superior divisional oculomotor nerve palsy following mild head trauma. Nystagmus accompanying a divisional oculomotor nerve palsy has never been reported before, making this case more unique. A critical step-wise approach to the case with possible mechanisms are discussed.