[Diagnosis of paraneoplastic neurological syndromes]

Paraneoplastic neurological syndromes are rare non-metastatic manifestations of malignancy. They are differentiated from side effects of tumor therapy, tumor-associated coagulopathy, infections, metabolic, and nutritional disorders. In the majority of cases neurological symptoms precede diagnosis of associated malignancy. Detection of anti-neuronal antibodies suggests a paraneoplastic mechanism.

To summarize syndromes, diagnostic steps, and currently available diagnostic possibilities.

Serum and/or cerebrospinal fluid is analysed using indirect immunfluorescence and Western blotting. The pattern of immunoreactivity suggests the type of antibody. Anti-Hu antibody immunolabels predominantly nuclei, and less the cytoplasm of central and peripheral nervous system neurons. Anti-Yo shows cytoplasmic immunoreactivity primarily of cerebellar Purkinje cells, while anti-Ri is somewhat similar to anti-Hu except that peripheral nervous tissue lacks immunoreactivity. Examination of non-neural tissue allows exclusion of nuclear immunostaining caused by other antinuclear antibodies. Western blot examination specifies the anti-neuronal antibody.

1. Paraneoplastic neurological syndromes may occur without defined malignancy. 2. Clinical diagnosis is supported by immunofluorescent/Western blot/ELISA detection of antibodies. 3. Knowledge of antibody may suggest the origin of malignancy. 4. Tumor and immunomodulatory therapy may be considered, however, prognosis is different in distinct tumors and syndromes.