PARANEOPLASTIC CEREBELLAR SYNDROME AND OPTIC NEURITIS WITH ANTI-CV2 ANTIBODIES - CLINICAL-RESPONSE TO EXCISION OF THE PRIMARY TUMOR

Objective: To describe a patient with a paraneoplastic cerebellar synd rome and optic neuritis with circulating anti-CV2 antibodies and clini cal improvement after excision of a small cell lung carcinoma. Design: Report of a case. Setting: A 62-year-old man simultaneously developed a severe cerebellar syndrome and a bilateral optic neuritis predomina ntly in the left eye (visual acuity, 20/25 in the right eye; <20/400 i n the left eye; and bilateral swelling of the optic discs). Main Outco me and Results: Anti-CV2 antibodies, recently described as associated with paraneoplastic neurological syndrome, were detected in the patien t's serum sample. These antibodies were demonstrated to react with the cytoplasm of a subpopulation of oligodendrocytes in the white matter of rat brain in the cerebellum, brainstem, spinal cord, and optic chia sm. The patient was found to have a small cell lung carcinoma, which w as removed. After excision of the tumor, the cerebellar syndrome impro ved dramatically and the papilledema disappeared despite aftereffects of the optic neuritis. Conclusions: These findings were consistent wit h the diagnosis of a paraneoplastic neurological syndrome, although bo th optic neuritis and remission of the cerebellar syndrome are uncommo n patterns of paraneoplastic syndromes. CV2 antigen expression by the oligodendrocytes of the cerebellum, brainstem, spinal cord, and optic chiasm correlated with the clinical syndrome observed in our patient. However, the precise pathophysiological role of anti-CV2 antibodies is still unknown.