Paraneoplastic syndrome is a set of symptoms that occur as a result of a tumor being present in the body, but not secondary to the cancer itself. Paraneoplastic symptoms occur as a result of the body's immune response to a tumor, or substances secreted by tumor cells. Paraneoplastic syndromes are thought to happen when cancer-fighting antibodies or white blood cells (known as T cells) mistakenly attack normal cells in the nervous system. These disorders typically affect middle-aged to older people and are most common in individuals with lung, ovarian, lymphatic, or breast cancer. Neurologic symptoms generally develop over a period of days to weeks and usually occur prior to the tumor being discovered. These symptoms may include difficulty in walking or swallowing, loss of muscle tone, loss of fine motor coordination, slurred speech, memory loss, vision problems, sleep disturbances, dementia, seizures, sensory loss in the limbs, and vertigo or dizziness.
When present, the tumor and cancer are treated first, followed by efforts to decrease the autoimmune response -- either through steroids such as cortisone or prednisone, high-dose intravenous immunoglobulin, or irradiation.
There are no cures for paraneoplastic syndromes. There are no available treatments to stop progressive neurological damage. Generally, the stage of cancer at diagnosis determines the outcome.