Paraneoplastic Neurological Syndromes (PNS) are a group of conditions that affect the nervous system in patients with cancer. They arise as a result of cancer-driven immunological reactions, rather than direct tumor invasion, metastasis, or side effects of treatment. The immune system produces antibodies (Ab) and lymphocytes to attack the cancer cells which yield collateral damage to healthy tissues in the nervous system. Paraneoplastic autoantibodies are thought to be surrogate markers of the tumor-associated neurological disease rather than directly pathogenic, as they target intracellular neuronal antigens which are not readily accessible to them.
Symptomology differs depending on the antibodies present and the area of the nervous system affected. Common symptoms include problems with movement and coordination, sensory perception, and memory.
In approximately 60% of patients, PNS symptoms occur before the diagnosis of cancer is made. Therefore early detection is crucial, both to increase the response of the patient to immunotherapy treatments and to permit early detection and excision of the tumor.
Frequently PNS affects only a single area of the nervous system. As the disease progresses, however, autoimmune attack can spread to other areas, meaning repeated neurological examinations must be performed in order to monitor the disease progression.
Testing for paraneoplastic autoantibodies is performed with commercial kits. Sera and cerebrospinal fluid (CSF) from patients are assessed for antibody titer. BC Neuroimmunology offers tests for the following antibodies:
- PNMA2 (Ma2/Ta)
- Tr (DNER)