Author response: Pearls & Oy-sters: Isolated oculomotor nerve palsy due to pituitary apoplexy missed on CT scan

We appreciate Dr. Pollak's comments about our paper.1 Indeed, although our patient's pupil ipsilateral to his third nerve palsy seemed briskly reactive at the bedside, this does not mean the parasympathetic pathway was intact. The anisocoria that we reported—with the right pupil larger than the left, especially in bright light—indicated parasympathetic pupillary dysfunction—i.e., failure of the right pupil to constrict appropriately to bright light—with this function being mediated by the parasympathetic fibers of the oculomotor nerve.2 This was exactly why we did not call this a pupil-sparing third nerve palsy. We agree with Dr. Pollak that the pupillary finding was not explained by physiologic anisocoria owing to the difference in bright vs dim light. There were no signs of trigeminal ophthalmic branch involvement in our patient.