Nervous system paraneoplastic syndrome

Introduction to the paraneoplastic syndrome of the nervous system Paraneoplastic syndrome (PNS) occurs in patients with certain malignant tumors. In the absence of tumor metastasis, it has developed a disease that affects distant organs and causes dysfunction. The affected distant organs are, for example, in the nervous system, also known as the neurological paraneoplastic syndrome. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious complication:

Nervous system paraneoplastic syndrome etiology

(1) Causes of the disease

The etiology of paraneoplastic syndrome is not well understood. It was previously thought that cancer may secrete certain substances that directly damage the nervous system, such as hormone-like substances and cytokines. The substance can cause hypercalcemia, weakness and behavioral abnormalities. The ectopic ACTH produced by the tumor can often cause Cushing's syndrome and behavioral abnormalities. Interleukin-1 and tumor necrosis factor can cause muscle atrophy and weakness. At present, the cause of paraneoplastic lesions is more likely to be autoimmune reactions caused by systemic or potential tumors.

(two) pathogenesis

Exploring the pathogenesis helps to elucidate the pathogenesis of autoimmune diseases and tumor immunology. The current pathogenesis has the following hypothesis:

1. Antibody-Mediated Theory Wilkinson (1964) describes the presence of autoantibodies in the serum of patients with neuromuscular disease. It has been confirmed that myeloma-like polyneuropathy, Lambert-Eaton syndrome, etc. are all related to antibody-mediated immune responses. Immunization of animals with paraneoplastic antigens or passive input of tumor antibodies replicates animal models that are identical to human paraneoplastic lesions and clinical manifestations.

2. Cellular immune mechanism in patients with tumor tissue and CNS pathological sections can be found, perivascular CD4+ T cells and CD19/20 B cells inflammatory infiltration, interstitial CD8 T cells, monocytes and macrophage infiltration; The peripheral blood lymphocyte phenotype of patients with -Hu antibody-positive PNS was significantly increased compared with anti-Hu antibody-negative patients and normal controls, and CD4 CD45 RO+ helper T lymphocytes were significantly increased. These cells secreted IFN-, suggesting specificity. Th1 helper cell subtype response, Th2 subtype hyperplasia is not obvious.

3. Genetic factors specific HLA-I or II gene products can present tumor antigens, but whether specific HLA haplotypes can cause paraneoplastic syndrome is still unclear, human HLA-B8, HLA-DQ and HLA-DR It is closely related to autoimmune diseases, but so far no specific HLA serotypes have been found in anti-Hu autoantibody carriers. The correlation between PNS and genetic factors needs to be confirmed.

Nervous system paraneoplastic syndrome prevention

Early detection, early treatment.

Nervous system paraneoplastic syndrome complications Complication

Paraneoplastic syndrome can affect many tissues and organs in the body, causing corresponding clinical manifestations such as arthritis, rash, endocrine dysfunction and the like.

Symptoms of the para -neoplastic syndrome of the nervous system Common symptoms, weakness, reflex, extensor, vertigo, diplopia, strabismus myoclonus

1. Paraneoplastic lesions may involve any part of the nervous system such as the brain, spinal cord, peripheral nerves, nerve-muscle joints and muscles. The paraneoplastic syndrome can be divided into more than 10 kinds, which are different clinical symptoms according to the damaged part. Signs, paraneoplastic syndrome can be divided into:

(1) involving the central nervous system: including cerebellar degeneration (PCD), paraneoplastic encephalomyelitis (PEM), paraneoplastic strabismic cerebral palsy-myoclonus (POM) and myelitis.

(2) involving peripheral nerves: rare, less than 1% of cancer patients have PNS involving peripheral nerves, including subacute sensory neuron disease (SSN), subacute motor neuropathy (SMN), sensory-motor or autonomic neuron disease, etc. .

(3) involving nerve-muscle joints and muscles: such as Lambert-Eaton myasthenic syndrome (LEMS), dermatomyositis, polymyositis and necrotizing myopathy.

2. Common clinical features of paraneoplastic syndrome

(1) Most patients with PNS symptoms appear before the tumor, and the primary tumor can be found several years later.

(2) Subacute onset, the symptoms develop to a peak in a few days to several weeks, and the symptoms and signs can be fixed at the same time. There are many severe dysfunctions or loss of working ability when the patient visits.

(3) The characteristic symptoms of PNS include cerebellar degeneration, marginal lobe encephalitis, etc., all suggesting paraneoplastic, cerebellar degeneration in patients with dizziness, diplopia and ataxia, mild sputum reflex.

(4) The number of cerebrospinal fluid cells increased, protein and IgG levels increased, and electrophysiological examination showed corresponding peripheral nerve or muscle lesions.

3. Five major antibodies related to this syndrome can be detected in patients' serum and CSF.

(1) Anti-Hu antibody (anti-neuron antibody), associated with paraneoplastic encephalomyelitis.

(2) Anti-Yo antibody, which is a specific anti-Purkinje cell antibody (APCA), which is associated with paraneoplastic cerebellar degeneration and reproductive or gynecological tumors.

(3) Anti-Ri antibody (anti-neuronal cytoskeletal antibody), associated with paraneoplastic strabismic eye myoclonus - myoclonus and breast cancer.

(4) Cancer-related retinopathy (CAR) antibodies.

(5) Anti-voltage-gated calcium channel antibodies, found in LEMS and patients with stiff syndrome (SMS), the first three antibodies have considerable specificity, can confirm the existence of cancer, so that doctors can check the relevant organs.

Examination of the paraneoplastic syndrome of the nervous system

1. Serum and CSF immunological examination.

2. Regular examination of hematuria.

3. Neurological CT, MRI examination.

4. Neuromuscular electrophysiological examination.

Diagnosis and differentiation of paraneoplastic syndrome of nervous system

Paraneoplastic syndrome is mainly based on the patient's clinical manifestations and related antibody tests. No primary tumors are easily misdiagnosed. Patients with persistent neurological symptoms are difficult to explain when they should be suspected of PNS. Neurologists have this syndrome. Vigilance is especially important.

Some patients with PNS have characteristic manifestations, such as PCD, POM and Lambert-Eaton syndrome, which are often associated with tumors. If no cancer is found in the system, regular review is needed. Cerebrospinal fluid and electrophysiological examination are helpful for diagnosis, serum or CSF-specific autoantibodies can confirm PNS and suggest potential tumor properties.

Pay attention to the identification of primary diseases of the nervous system.

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