Paraneoplastic neurologic syndromes. Diagnostic and pathogenetic significance of autoantibodies

Abstract

Paraneoplastic neurologic syndromes (PNS) are rare disorders of the nervous system that cannot be ascribed to metastases or to destruction of vital systemic organs by the tumor or its treatment. Most frequently, PNS occur in association with small-cell lung, breast or ovarian carcinomas. The most frequent PNS is Lambert-Eaton myasthenic syndrome, which at the same time has the highest predictive value concerning an underlying carcinoma. PNS have been classified mostly under anatomical aspects but now are increasingly categorized according to specific antibodies. In certain neurologic syndromes (sensible and autonomic neuropathy, cerebellitis, limbic encephalitis, Opsoclonus-Myoclonus syndrome, Stiff-man syndrome, neuromyotonia, subacute amaurosis) specific autoantibodies are highly predictive for a neoplasm. Pathogenic relevance of these autoantibodies has been demonstrated only for antibodies against (1) voltage gated calcium channels (VGCC) in Lambert-Eaton myasthenic syndrome, (2) voltage gated potassium channels (VGKC) in neuromyotonia, and (3) recoverin in cancer associated retinopathy. The present article deals with the neurological symptoms of PNS, associated tumors, and the relevance of specific antibodies for the diagnosis and pathogenesis of PNS.