Therapy for Paraneoplastic Nervous System Syndromes

Whereas idiopathic OM often resolves, spontaneously or after administration of intravenous immunoglobuline or corticosteroids [58], the outcome of paraneoplastic OM is more variable and depends on the tumor response to therapy. Children with paraneoplastic OM frequently respond to chemotherapy, adrenocorticotropic hormone, or immunomodulation [223], The response to immune therapy in adults with paraneoplastic OM is very modest, but prompt tumor therapy, immunomodulation, and depletion of IgG may be of some benefit [62, 224], Without antineoplastic therapy, the prognosis is usually poor, and symptoms often progress, ultimately causing death [62], 

The evidence of an autoimmune pathogenesis supports the use of immunomodulatory therapy in PNS. If therapy is started at an early stage of the disease, the chances of neurological improvement are better, both with intravenous immunoglobuline alone [225] and with plasmapheresis and chemotherapy in combination even if no tumor has been diagnosed [226]. 

As a general rule, patients with PNS of the neuromuscular junction benefit considerably from cancer therapy. Immunotherapy of paraneoplastic LEMS, such as prednisone or plasmapheresis, can improve the symptoms for a while as the pathogenic VGCC antibodies are removed, but effective treatment of the underlying tumor is the cornerstone of therapy [201, 231], 

Some PNS cases run an indolent natural course [232], or the PNS may improve spontaneously [233]. Spontaneous remission should always be considered when patients seem to improve by oncological therapy or immunomodulation. 

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