A 58-year-old woman had opsoclonus and signs of cerebellar disease in association with carcinoma of the breast. The case is the first recorded with this abnormal ocular movement and neuroanatomic changes restricted to the cerebellum. Necropsy revealed typical changes of parenchymatous degeneration: absence of Purkinje cells, diffuse and focal gliosis, and neuronal loss in the granular layer and dentate nuclei. Opsoclonus differs clinically from other abnormal, conjugate movements of the eyes because it is spontaneous, irregular, multidirectional, and most severe at the onset of attempts to change fixation. Opsoclonus may occur in patients with encephalitis, polymyoclonia, and neoplastic disease, particularly neuroblastoma.
Ellenberger C, Netsky MG. Anatomic Basis and Diagnostic Value of Opsoclonus. Arch Ophthalmol. 1970;83(3):307-310. doi:10.1001/archopht.1970.00990030309007