We treated two patients with partial. oculomotor paresis who had pupil
lary mydriasis, marked inferior rectus muscle weakness, and medial rec
tus 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 a
nd suggest that fascicular medial rectus and inferior rectus muscle fi
bers are adjacent to each other.