Paraneoplastic syndromes of the nervous system are a group of rare disorders that develop in some people who have cancer. Paraneoplastic syndromes of the nervous system are the most commonly reported paraneoplastic syndromes, but these syndromes can also affect other organ systems including hormone (endocrine), skin (dermatologic), blood (hematologic) and joints (rheumatologic). Paraneoplastic events may also in part explain some of the most common symptoms of cancer, such as fatigue, loss of appetite for food (anorexia) and weight loss. Paraneoplastic syndromes of the nervous system occur when cancer-fighting agents of the immune system also attack parts of the brain, spinal cord, peripheral nerves or muscle.
Signs and symptoms of paraneoplastic syndromes of the nervous system usually develop relatively quickly, often over days to weeks. Signs and symptoms vary depending on the body part being injured.
Cerebellar degeneration. This is the loss of nerve cells in the area of the brain that controls muscle functions and balance (cerebellum).
Limbic encephalitis. This is inflammation affecting a region of the brain known as the limbic system, which controls emotions, behaviors and certain memory functions.