See-Saw Nystagmus

7-year-old female whose mother noticed her eyes “bouncing“ for 2 months. Visual acuity 20/70 OD and 20/40 OS, reduced color vision OU, and no afferent pupillary defect. See-saw nystagmus documented with videography. Manual perimetry revealed a complete right homonymous hemianopia. MRI revealed a large, enhancing, heterogeneous mass in the hypothalamic region. Images shown are sagittal and coronal T1 images with contrast. Biopsy was consistent with a juvenile pilocytic astrocytoma. The patient underwent chem