Multiple sclerosis presenting as Parinaud syndrome.

The authors report a patient presenting with a 1-week history of paresis of upward gaze as his initial manifestation of demyelinating disease. They stress that: 1) multiple sclerosis can present as Parinaud syndrome (paralysis of upward gaze); and 2) it is important to rule out a non-contour-deforming intraaxial midbrain lesion if a posterior third ventricle or pineal region mass is not identified on screening studies in these patients.