Purpose: To establish the contemporary aetiology of adult superior oblique palsy (SOP).
Materials and methods: A retrospective consecutive case series of 150 persons diagnosed with SOP between 1 January 1999 and 31 May 2005 at a neuro-ophthalmology centre in the West Midlands, the United Kingdom. Interrogating two different hospital databases identified all cases. A case note review was performed on all participants to determine demographics and aetiology based on diagnostic criteria, neuroimaging used, and outcome.
Results: We identified 133 unilateral isolated, 7 unilateral associated with other cranial nerve involvement, and 10 bilateral cases of SOP. Eighty-six were acquired, 51 congenital, and 13 undetermined. Of the unilateral isolated cases, 38.3% were considered to be congenital, 29.3% followed trauma, 23.3% were presumed to be vasculopathic in origin, and no cause could be established in 7.5%. All presumed microvascular-associated palsies resolved within 6 months of presentation. Unilateral SOPs associated with other cranial nerve palsies were commonly caused by trauma (71.4%), followed by tumour and undetermined causes (both 14.3%). Trauma was the most frequent cause of bilateral SOP (50%), followed by tumours and undetermined causes (both 20%), with congenital causes being uncommon (10%).
Conclusion: We present a contemporary aetiological spectrum for adult SOP, with the lowest incidence of undetermined cases published in the medical literature. Neuroimaging did not change the management for the vast majority of cases and should be prompted by atypical presentations.