Jung and Kim Dovepress Figure 1 Nine cardinal directions of gaze showing exodeviation, limitation of adduction, and infraduction in the right eye at initial visit. findings were unremarkable, with the exception of positive rheumatoid factor (titer 1:320) and antinuclear antibody (mitotic spindle fiber type, titer 1:620). Brain magnetic resonance imaging with gadolinium enhancement revealed no abnormal findings. We believed that the patient had pupil-sparing incomplete third nerve palsy (mainly involving the inferior division) related to autoimmune disease, so admitted her and treated her with intravenous methylprednisolone 250 mg four times daily for three days, and tapered the steroid thereafter. Her extraocular movements resolved completely at two weeks after steroid pulse therapy. The last follow-up visit was per- formed six weeks after the initiation of steroid pulse therapy. During the follow-up period, she manifested no significant neurological sequelae. Discussion Anti-MSA antibodies are not associated with a defined auto- immune pathology, but some studies have reported anti-MSA in the sera of patients with connective tissue diseases, infec- tions, autoimmune hepatitis, vasculitis, primary antiphospho- lipid syndrome, malignancy, and fever of unknown origin.4,5 The aforementioned autoimmune diseases are well associated with oculomotor nerve palsy. However, the present report is 550 submit your manuscript | www.dovepress.com Dovepress the first reported case of a patient with isolated oculomotor nerve palsy associated with anti-MSA. The mitotic spindle apparatus is a unique structure of microtubules and associated proteins involved in the segregation and reorganization of chromosomes during cell division. Anti-MSA is identified during the immunofluorescent detection of antinuclear anti- bodies, which are associated with autoimmune diseases.6,7 There are two possible mechanisms related to this cranial neuropathy with autoimmune diseases, namely “vascular” (due to damage of the vasa nervorum) or an “immunologic cause” (due to lymphocytic infiltration of the nerve).8 The patient had an excellent and rapid response to intravenous methylprednisolone treatment and completely recovered two weeks after the start of steroid pulse therapy. Therefore, lymphocytic infiltration or autoantibodies to components of the cranial nerves might play an important role. Lui et al2 also reported on a patient with unilateral oculomotor nerve palsy and Sjogren’s syndrome who experienced an almost complete recovery of both ptosis and diplopia after two weeks of treatment, and an immunologic neuropathic process was thought to be the cause. In conclusion, although oculomotor nerve paralysis is usually believed to be self-limiting, steroid pulse therapy should be considered in cases of ocular paralysis when Clinical Ophthalmology 2011:5