Paraneoplastic cerebellar degeneration.

One of the most dramatic and devastating examples of a remote effect of cancer is paraneoplastic cerebellar degeneration (PCD). There is convincing evidence that this disorder is caused by autoimmunity directed against cerebellar targets. Typically, the neurological presentation antedates the diagnosis of malignancy, and the cancer, when found, tends to be localized and responsive to treatment. Diagnosis depends on clinical suspicion, serology for paraneoplastic antibodies, and a focused search for cancer. Neuronal autoantibody tests facilitate the diagnosis and help direct the search for malignancy. Unfortunately, even with prompt diagnosis, current treatment strategies meet with limited success. Optimum management includes early diagnosis, treatment of cancer to remission, immunosuppression, symptomatic therapies, and compassionate support.