Parinaud's syndrome - A rare presentation of clinically isolated syndrome.

We present a 26 year old Pakistani lady with first presentation of a demyelinating event, presenting as Parinaud's syndrome. The video demonstrates a convergence-retraction nystagmus on upgaze and failure of accommodation, and her brain imaging confirms a corresponding pre-tectal contrast enhancing T2 hyperintense lesion suggestive of demyelination. A review of the literature is presented.