A rare cause of reversible unilateral third nerve palsy.

Case Report: A 59-year-old Chinese male presented in January 2007 with acute left retro-orbital headache, diplopia and left partial ptosis. Isolated left third nerve palsy was diagnosed. Imaging studies and cerebral angiography excluded a posterior communicating artery aneurysm. Anti-nuclear (titre 1/800, speckled pattern), anti-PR3, anti-Ro and anti-La antibodies were present. Sjogren's syndrome (SS) was considered in view of positive anti-Ro and La antibodies, and was confirmed with focal lymphocytic infiltrates on labial salivary gland biopsy and a positive Schirmer's test (6 mm of tear flow over 5 min). Immunosuppressive therapy was started 2 months after his initial presentation and within 2 weeks, the patient experienced an almost complete recovery of both ptosis and diplopia. He has been on tapering doses of prednisolone since and his condition remains stable.

Conclusion: This patient has cranial neuropathy secondary to Sjogren's syndrome. The rapid reversibility of the oculomotor nerve palsy with immunosuppression suggests lymphocytic infiltration or autoantibodies as the cause rather than a vasculitic process, which would have led to irreversible or slowly, partially reversible ischaemic damage.