A Case of Pupil-Sparing Oculomotor Nerve Palsy due to Midbrain Infarction in Diabetic Patient

BACKGROUND: In general, vasculopathic oculomotor nerve palsy with pupil-sparing implied a lesion in the subarachnoid space or the cavernous sinus; however, it has been reported that similar findings can be produced by fascicular lesion. CASE: A 48-year-old woman with diabetes mellitus complained of diplopia and right ptosis. Examination revealed a complete oculomotor nerve palsy of the right eye with sparing of the pupil. The MRI revealed a infarction in the fascicular portion of the oculomotor nerve. CONCLUSION: It is emphasized that the intraaxial lesion should be ruled out using the sophisticated study in patients with pupil-sparing vasculopathic oculomotor nerve palsy.