Paraneoplastic neurological syndromes: diagnosis and treatment

The most relevant advances in the field of paraneoplastic neurological syndromes are described, with special emphasis on particular clinical-immunological associations and practical issues for the diagnosis and treatment of these disorders.

Paraneoplastic neurological syndromes may present with classical neurological symptoms or less frequently with symptoms that do not initially raise suspicion of these disorders. Recent examples include patients who present with epilepsia partialis continua or frontal disequilibrium associated with Hu antibodies, hypersommnia and anti-Ma2 antibodies, Devic's syndrome and CV2/CRMP5 antibodies and a syndrome characterized by psychiatric features and central hypoventilation in young women with anti-N-methyl-D-aspartate receptor antibodies. The cause of the neuronal damage is still open to debate. The recent description of antibodies against membrane proteins in opsoclonus or encephalitis associated with teratoma strongly suggests that antibodies may be responsible for the clinical features in some cases. Early diagnosis and effective treatment of the tumor remain the best options to improve or stabilize the syndrome. Immunotherapy, including rituximab, seems effective in those cases associated with functional damage.

Neurologists must be aware of neurological syndromes that may have a paraneoplastic origin. Detection of onconeural antibodies is crucial to make the correct diagnosis. Immunotherapy should be used, although the impact of the treatment is unclear in cases with irreversible neuronal damage.