Fascicular arrangement in partial oculomotor paresis.

We treated two patients with partial oculomotor paresis who had pupillary mydriasis, marked inferior rectus muscle weakness, and medial rectus muscle paresis, which were attributed to an ipsilateral fascicular lesion, demonstrated on neuroimaging studies. These cases support the fascicular proximity of inferior rectus muscle and pupillary fibers and suggest that fascicular medial rectus and inferior rectus muscle fibers are adjacent to each other.