Paraneoplastic neurological syndromes (PNS) are diseases of the central and peripheral nervous system that occur in direct relation to tumour development. However, these are not caused directly by the tumour, by its metastases or by any side-effects from therapy using cytostatic drugs or radiation treatment. PNS occur in approximately 15% of malignant diseases, particularly in lung tumours.

Depending on the type of tumour, tumour cells express antigens, e.g. amphiphysin, CV2/CRMP5, PNMA2 (Ma2/ Ta), Ri, Yo, Hu, ZIC4 or Tr (DNER) which can induce the formation of specific autoantibodies. These autoantibodies bind to the respective antigens localised in the nervous tissue and can thus cause neurological disorders.

In the literature two types of nomenclature are used for PNS-specific autoantibodies. One is based on the first two letters of the index patient's name (e.g. Hu for Hull, Yo for Young, Ma for Margret), the other on the initial letters of the immunohistochemical staining (ANNA = anti-nuclear neuronal antibodies). We use the nomenclature of Posner (anti-Hu, -Yo, -Ma etc.), since this is antigen-based and independent of the test procedure.