Paraneoplastic Neurologic Syndromes (PNS) are remote effects of malignancy involving the nervous system not related to tumor invasion, compression, or metastasis. These syndromes are rare, with approximately 1% of adults with cancer having an associated PNS. They are immunologic in origin where malignancy triggers production of autoantibodies against various antigens of the nervous system, as antigens located on the tumor mimic those of the nervous system.