Corneal Anesthesia and Brun's Nystagmus Following Resection of Pilocytic Astrocytoma at the Inferior Cerebellar Peduncle

A 7-year-old girl initially presented with headaches and vomiting and was diagnosed with a right inferior cerebellar peduncle pilocytic astrocytoma with mild local mass effect on the medulla and right cerebellum. Six months following subtotal resection, she developed large amplitude right beating nystagmus in right gaze and fine left beating torsional nystagmus resembling Brun's Nystagmus and adopted a right head turn to minimize oscillopsia. Her neurological exam also revealed mild difficulties with tandem gait. Prisms were used to shift the null point and minimize her head turn in anticipation of future strabismus surgery. She later developed neurotrophic keratopathy and corneal ulceration from corneal anesthesia as well as a non-healing right sided nasal wound from trigeminal trophic syndrome. She was managed with tarsorrhaphy and corneal neurotization.