A rare cause of reversible unilateral third nerve palsy

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.

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.