Retinal disease masquerading as spasmus nutans.

Two children with congenital stationary night blindness were originally diagnosed as having spasmus nutans. Both children had the typical features of spasmus nutans including asymmetric nystagmus, head shaking, and torticollis. The diagnosis of congenital stationary night blindness was established only after each child underwent electroretinography. The nystagmus associated with retinal disease can mimic many of the features of spasmus nutans. Children suspected of having spasmus nutans should undergo complete ophthalmologic examination and electroretinography if they are myopic.