Definition
Paraneoplastic syndromes of the nervous system are a group of rare disorders that develop in individuals who have cancer. These syndromes are most common among middle to older age individuals with lung cancer, breast cancer or ovarian cancer.
Paraneoplastic syndromes of the nervous system occur when cancer fighting agents of the immune system target and attack parts of the brain, spinal cord, peripheral nerves or muscle. The syndromes can affect any part of the nervous system and in turn cause common symptoms of cancer such as tiredness, inability to eat, loss of muscle coordination, slurred speech, memory loss, vision problems and weight loss.
Treatment for paraneoplastic syndromes typically involves treating the cancer itself, improving symptoms and physical therapy if necessary.
Symptoms
Signs and symptoms of paraneoplastic syndromes of the nervous system vary depending on the location of the damaged body part. Symptoms can develop quickly, often over days to weeks and can include:
- Loss of muscle coordination
- Muscle weakness
- Trouble speaking/swallowing
- Blurred or double vision
- Memory loss
- Seizures
- Difficulty walking/maintaining balance
- Uncontrollable or jerky movements
- Loss of fine motor coordination (grasping objects)
- Sleep problems
Common types of paraneoplastic syndromes include:
- Cerebellar degeneration: A process which leads to loss of nerve cells in the area of the brain that controls muscle coordination and balance. Common symptoms may include muscle weakness, loss of muscle coordination, sickness, dizziness, speech impairment and blurred vision.
- Encephalomyelitis: A disease that causes Inflammation of the brain and spinal cord. Symptoms vary depending on the area affected.
- Limbic encephalitis: A rare disorder that causes inflammation of the limbic system (the area of the brain that controls behavior and memory function). Common symptoms may include mood swings, memory loss, seizures, hallucinations or sleep apnea.
- Stiff person syndrome: A condition that causes severe muscle stiffness which affects the spine and legs. Most common symptoms include painful muscle spasms.
- Opsoclonus-myoclonus: A neurological disorder that causes loss of function in the area of the brain that controls fine motor coordination. Common symptoms may include uncontrollable or jerky movements in the limbs and trunk as well as unusual eye movements (opsoclonus).
- Myelopathy: A nervous system disorder that affects the spinal cord. Common symptoms may include weakness and numbness in the body and changes in bowel and bladder function
- Lambert-Eaton myasthenic syndrome: A rare disorder that causes disruptions among the communication between nerve signals and muscles. Common symptoms may include tiredness, slurred speech, unusual eye movements, double vision, and difficulty swallowing and muscle weakness.
- Neuromyotonia: An inflammatory disorder caused by abnormal nerve impulses outside the brain and spinal cord that control muscle movement. Common symptoms may include muscle cramps, muscle rippling and twitching.
- Peripheral neuropathy: A condition that involves damage to the nerves that transmit messages from the brain to the rest of the body. Common symptoms can include painful instances anywhere in the body.
- Myasthenia gravis: A condition that causes muscle weakness and tiredness under voluntary control, including the muscles in the face, eyes, arms and legs. The muscles involved in chewing, swallowing, talking and breathing may be affected as well.
- Dysautonomia: A wide range of medical conditions that result from damage to the nerves that control bodily functions such as heart rate, blood pressure, bowel and bladder functions, etc. Common symptoms can include hypotension, sickness, and bloating and weight loss.
Causes
Paraneoplastic syndromes occur as a result of cancer in the body that cause the immune system to react. Instead of only attacking cancer cells, the cancer fighting agents of the immune system (antibodies and certain white blood cells) also target and attack the normal cells of the nervous system, thus causing neurological disorders.
Other neurological problems may be related to cancers that develop and affect the brain or spinal cord. These tumors can cause tissue injury that can result in damages to the nervous system. For example; a tumor may put pressure on a nerve or on the spinal cord.
Risk factors
Although any cancer may be associated with a paraneoplastic syndrome of the nervous system, most often individuals with lung cancer, breast cancer or ovarian cancer are at a higher risk of developing the condition. Also, individuals with a personal or family history of autoimmune disease are likely to experience paraneoplastic effects from a cancer.
Treatment
Treatment of neurologicalparaneoplastic syndromes involves treating the cancer and improving symptoms that cause pain and discomfort. Treatment options can include:
- Corticosteriod medications (prednisone) to reduce inflammation
- Immunosuppressants to help slow production of disease fighting white blood cells
- Anti-seizure medications, if necessary, to help control seizures and provide electrical stability in the brain
- Certain medications to enhance nerve to muscle transmission
Other medical procedures may include:
- Plasmapheresis: A method used to remove blood plasma from the body that contains unwanted antibodies by withdrawing blood, separating it into plasma and cells and transfusing the red and white blood cells back into the bloodstream.
- Intravenous immunoglobulin (IVIG): a method that involves injecting high doses of immunoglobulin (healthy antibodies) to help speed up the process of destroying damaging antibodies in the blood.
Other types of therapies that may be helpful if a paraneoplastic syndrome has caused significant disability include:
· Physical therapy: A rehabilitation program that uses specific exercises to help regain muscular function and coordination.
· Speech therapy: A clinical program aimed to help improve speech skills as well as oral motor skills to relearn muscle control.
