Neurologic Paraneoplastic Syndrome

Paraneoplastic syndromes (PNS) occur in some malignancy patients when, without tumor metastasis, distant self-organs are affected and develop functional disturbance. When the affected distant organ is the nervous system, it is called neurologic paraneoplastic syndrome.

Common Symptoms

Weakness; diplopia; myoclonus; strabismus; vertigo; extensor plantar response

Causes and Pathogenesis

(A) Etiology: PNS cause is not fully clear. Previously thought due to cancer secreting substances directly damaging the nervous system, e.g. hormone-like substances and cytokines: hormone-like substances cause hypercalcemia, weakness, behavioral abnormality; ectopic ACTH causes Cushing's syndrome and behavioral abnormality; IL-1 and TNF cause muscle atrophy and weakness. Current view favors systemic or occult tumor triggering autoimmune reaction. (B) Mechanism: Mechanistic studies help clarify autoimmune disease and tumor immunology. Hypotheses: 1. Antibody-mediated theory: Wilkinson (1964) described autoantibodies in tumor patients with neuromuscular disease; proven for myelomatous polyneuropathy and Lambert-Eaton syndrome. Immunizing animals with paraneoplastic antigens or passive transfer of tumor antibodies reproduces human-like lesions. 2. Cellular immunity: tumor and CNS sections show perivascular CD4+ T and CD19/20 B-cell inflammatory infiltrates, with interstitial CD8 T cells/monocytes/macrophages; anti-Hu-positive PNS patients have significantly increased CD4 CD45RO+ helper T cells secreting IFN-γ, indicating Th1-subtype response with little Th2 proliferation. 3. Genetic factors: specific HLA class I/II gene products present tumor antigens, but whether specific HLA haplotypes cause PNS is unclear. HLA-B8/DQ/DR relate to autoimmune disease, but no specific HLA serotype has been found in anti-Hu carriers; PNS-genetics correlation needs further study.

Treatment

Surgery, supportive therapy

Preventive Measures

Early detection, early treatment.

Department to Visit

It is recommended to visit the Medical Oncology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.