Isolate unilateral oculomotor palsy after mild traumatic brain injury.

Isolated traumatic oculomotor nerve (ON) palsy is an uncommon clinical presentation of mild traumatic brain injury (TBI). There are very few cases in which it has been possible to demonstrate the isolated damage of the ON by avulsion of the roots, accompanied with traumatic axonal injury and intraneural microhemorrhage. We present a 23-year-old female who, after mild TBI, began to experience right ptosis, binocular diplopia, and photophobia. Clinical examination showed a complete ophthalmoparesis of the right ON, without other neurological deficits. Neuroimaging studies demonstrated no structural compressive damage of the right ON. Magnetic resonance imaging (MRI) with Gradient-echo and T1 weighted post-gadolinium was made, demonstrating signs of intraneural hemorrhage of the right ON, in addition to traumatic axonal injury extending from the right cerebral peduncle to the orbital fissure. Specific MRI protocols contribute as evidence of an isolated lesion to the ON.