Partial Oculomotor Nerve Palsy due to Different Fascicular Involvements in Recurrent Midbrain Infarctions

ABSTRACT

We experienced a patient with partial oculomotor palsy who had initially manifested pupillary mydriasis and inferior rectus palsy which were attributed to an ipsilateral fascicular lesion in midbrain. She developed ipsilateral ptosis and monocular elevation palsy due to a new lesion on MRI one month later. This case could be the first neuroimaging evidence which support the hypothesis that fascicles of the oculomotor nerve for inferior oblique, superior rectus, and levator palphebrae muscle fibers are located more laterally and caudally than fascicles for pupil and inferior rectus muscle within midbrain tegmentum.