Superior oblique muscle paralysis in the CREST syndrome.

A 54 year old male with the CREST (Calcinosis, Raynauds, Esophageal hypomotility, Sclerodactyly, Telangiectasia) variant of progressive systemic sclerosis (PSS) presented with vertical diplopia diagnosed as a left superior oblique muscle paralysis. Although cranial nerves abnormalities have been reported in PSS, to our knowledge this is the first report of the CREST syndrome in association with a IV nerve palsy in whom no other etiology could be found.