Teaching NeuroImages: dorsal midbrain (Parinaud) syndrome with corectopia.

A 13-year-old boy presented with emesis, blurred vision, headache, and vertigo. He showed signs of a dorsal midbrain (Parinaud) syndrome (supranuclear upgaze palsy, convergence retraction nystagmus, Collier sign [lid retraction], pupillary light-near-dissociation)1 and eccentric displacement of the pupils (corectopia; figure 1 and figure e-1 on the Neurology Web site at www.neurology.org). Fundi and visual acuity were unremarkable. Further investigations revealed a germ cell tumor in the pineal region (figure 2). All neuro-ophthalmologic signs resolved under therapy. As in our case, Parinaud syndrome can be accompanied by corectopia, which is considered to be due to unequal inhibition of portions of the Edinger-Westphal nuclei leading to segmental relaxation in the iris sphincters.2