(2) OAS can lead to dysfunction of the ophthalmic branch of the trigeminal nerve (cranial nerve V1), oculomotor nerve (cranial nerve III), trochlear nerve (cranial nerve IV
), abducens nerve (cranial nerve VI), and optic nerve (cranial nerve II).
A section of cranial nerve IV
showed mononuclear lymphocytic infiltrate and mild myelin loss, while sections of the sciatic nerve showed inflammation-associated myelin loss.
Pupil-sparing oculomotor nerve palsy was seen in the right eye, but the trochlear nerve (cranial nerve IV
) and the abducens nerve (cranial nerve VI) were both intact (figure 1).
* Cranial nerve IV
is the only cranial nerve to emerge from the dorsal aspect of the brain.
The physical examination at admission was notable for dilated, asymmetric (5 mm on the right and 4 mm on the left), sluggishly reactive pupils; cranial nerve IV
palsy; bilateral proptosis (right more than left); bilateral peripheral facial weakness; and proximal left upper extremity weakness.