What are paraneoplastic syndromes of the nervous system?
Paraneoplastic syndromes of the nervous system are a group of conditions that affect the nervous system (brain, spinal cord, nerves and/or muscles) in patients with cancer. The term “paraneoplastic” means that the neurological syndrome is not caused by the tumor itself, but by the immunological reactions that the tumor produces.
It is believed that the body’s normal immunological system interprets the tumor as an invasion. When this occurs, the immunological system mounts an immune response, utilizing antibodies and lymphocytes to fight the tumor.
The end result is that the patient’s own immune system can cause collateral damage to the nervous system, which can sometimes be severe. In many patients, the immune response can cause nervous system damage that far exceeds the damage done to the tumor. The effects of paraneoplastic syndromes of the nervous system can remit entirely, although there can also be permanent effects.
How common are paraneoplastic syndromes of the nervous system?
In general, paraneoplastic syndromes of the nervous system are considered rare disorders. However, some paraneoplastic syndromes of the nervous system such as the paraneoplastic neuropathies are relatively frequent, affecting approximately 10% of patients with some cancers of the immunological system.
Paraneoplastic syndromes of the nervous system affect males and females in equal numbers. In general paraneoplastic syndromes of the nervous system are more common in older patients as they more frequently develop those cancers associated with paraneoplastic syndromes of the nervous system.
However, paraneoplastic syndromes of the nervous system can occur in children and teenagers and as noted above there are some paraneoplastic syndromes of the nervous system (e.g., paraneoplastic anti-NMDAR encephalitis) that more commonly affect younger patients.
Please discuss with your doctor for further information.
What are the symptoms of paraneoplastic syndromes of the nervous system?
The common symptoms of paraneoplastic syndromes of the nervous system are:
- Difficulty walking
- Difficulty maintaining balance
- Loss of muscle coordination
- Loss of muscle tone or weakness
- Loss of fine motor skills, such as picking up objects
- Difficulty swallowing
- Slurred speech or stuttering
- Memory loss and other thinking (cognitive) impairment
- Vision problems
- Sleep disturbances
- Unusual involuntary movements
Signs and symptoms of paraneoplastic syndromes of the nervous system can develop relatively quickly, often over days to weeks. Signs and symptoms of paraneoplastic syndromes of the nervous system often begin even before a cancer is diagnosed.
Types of paraneoplastic syndromes
Examples of paraneoplastic syndromes of the nervous system include:
- Cerebellar degeneration. This is the loss of nerve cells in the area of the brain that controls muscle functions and balance (cerebellum). Signs and symptoms may include unsteady or impaired walking, lack of muscle coordination in your limbs, inability to maintain your trunk posture, dizziness, nausea, involuntary eye movement, double vision, difficulty speaking, or difficulty swallowing.
- Limbic encephalitis. This is inflammation affecting a region of the brain known as the limbic system, which controls emotions, behaviors and certain memory functions. People with this disorder may experience personality changes or mood disturbances, memory loss, seizures, hallucinations, or drowsiness.
- This syndrome refers to inflammation of the brain and spinal cord. There may be a wide variety of symptoms and signs depending on the area affected.
- Opsoclonus-myoclonus. This syndrome is due to dysfunction of the cerebellum or its connections. It can cause rapid, irregular eye movements (opsoclonus) and involuntary, chaotic muscle jerks (myoclonus) in your limbs and trunk.
- Stiff person syndrome. Previously called stiff man syndrome, this syndrome is characterized by progressive, severe muscle stiffness or rigidity, mainly affecting your spine and legs. It may also cause painful muscle spasms.
- This term refers to a syndrome of injury limited to the spinal cord. Depending on the level of spinal cord injury, you may have changes in bowel and bladder function, and severe weakness and numbness up to a certain level in your body. If the level of injury includes your neck, you can have severe disability affecting all four limbs.
- Lambert-Eaton myasthenic syndrome. This is a syndrome caused by disrupted communication between nerves and muscles. Signs and symptoms include pelvic and lower extremity muscle weakness, fatigue, difficulty swallowing, difficulty speaking, irregular eye movement, and double vision. Autonomic nervous system problems can include dry mouth and impotence. When it occurs as a paraneoplastic syndrome, Lambert-Eaton myasthenic syndrome is typically associated with lung cancer.
- Myasthenia gravis. Myasthenia gravis is also related to disrupted communication between nerves and muscles and also characterized by weakness and rapid fatigue of any of the muscles that are under voluntary control, including muscles in your face, eyes, arms and legs. The muscles involved in chewing, swallowing, talking and breathing may be affected as well. When myasthenia gravis occurs as a paraneoplastic syndrome, it is typically associated with cancer of the thymus gland (thymoma).
- Neuromyotonia — also known as Isaacs’ syndrome — is characterized by abnormal impulses in nerve cells outside the brain and spinal cord (peripheral nerve hyperexcitability) that control muscle movement. These impulses can cause twitching, muscle rippling that looks like a “bag of worms,” progressive stiffness, muscle cramps, slowed movement and other muscle impairments.
- Peripheral neuropathy. This condition refers to patterns of damage to nerves that transmit messages from the brain or spinal column to the rest of your body. When damage involves only the sensory nerves of the peripheral nervous system, you can have pain and disturbances in sensation anywhere in your body.
- Dysautonomia refers to a wide range of signs and symptoms resulting from injury to the nerves that regulate nonvoluntary body functions (autonomic nervous system), such as heart rate, blood pressure, sweating, and bowel and bladder functions. When this part of the nervous system is affected, common symptoms are low blood pressure, irregular heartbeats and trouble breathing.
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes paraneoplastic syndromes of the nervous system?
The specific cause of paraneoplastic syndromes of the nervous system is unknown. The findings in the serum or cerebrospinal fluid (CSF) of antibodies (onconeural antibodies) to specific malignant tumors suggest that the cause of some paraneoplastic syndromes of the nervous system is the immune response against the tumor being misdirected against the nervous system.
What increases my risk for paraneoplastic syndromes of the nervous system?
Any cancer may be associated with a paraneoplastic syndrome of the nervous system. However, the disorders occur more often in people with cancers of the lung, ovary, breast, testis or lymphatic system.
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How are paraneoplastic syndromes of the nervous system diagnosed?
Patients with a suspected paraneoplastic syndrome should receive a complete panel of laboratory studies, including blood, urine, and CSF. In addition, the use of an MRI, EEG (electroencephalogram), and EMG (electromyogram) can further display abnormalities that help to diagnose paraneoplastic syndromes of the nervous system.
Many (but not all) patients with paraneoplastic syndromes of the nervous system have paraneoplastic antibodies in their blood and/or CSF. If any of these antibodies are identified, then the diagnosis of paraneoplastic syndromes of the nervous system is strongly supported or definite (depending on the type of antibody).
It should be understood that there are three types of antibodies that associate with neurological syndromes. There is one type that associates with specific neurological syndromes but not with cancer. Another type includes antibodies that almost always associate with the presence of cancer. The third type of antibodies includes those that may occur with or without cancer. Therefore, it is important to understand the relative value of each category of antibodies in suggesting that the neurological syndrome is paraneoplastic or not.
Once a diagnosis of or a suspicion of a paraneoplastic syndrome of the nervous system is apparent, other tests are used to identify the location and type of tumor. These include CT scanning (usually of the chest, abdomen, and pelvis), mammography, ultrasound, PET scan, and blood tests for specific tumor markers (such as the CA125, for ovarian cancer). The type of paraneoplastic antibody often helps to direct the search of the tumor to a specific organ (for example, most patients with Hu antibodies have lung cancer).
How is paraneoplastic syndromes of the nervous system treated?
Except for a few paraneoplastic syndromes of the nervous system of the peripheral nerves and neuromuscular junction, there is no general consensus yet for treating many of these syndromes. However, there are several principles in which most investigators agree upon:
The tumor is the main trigger for all paraneoplastic syndromes of the nervous system. Therefore, in general, prompt identification and treatment of the tumor is essential. Thus, the first therapeutic option is usually surgery, radiation, or chemotherapy (singly or in combination).
Because many paraneoplastic syndromes of the nervous system are immune-mediated, immunotherapy should be considered based on the type of antibody involved. Paraneoplastic syndromes of the nervous system in which the antibody attacks the cell-surface of neurons respond better to immunotherapies than paraneoplastic syndromes of the nervous system in which the antibodies react with proteins that are inside the neurons (or intracellular antigens).
The usage, timing, and type of immunotherapy will vary depending on the specific type of paraneoplastic syndromes of the nervous system and/or whether the tumor is being treated at the same time.
In a patient who has been in remission from a cancer treated within the prior five years, symptoms that appear to be a paraneoplastic syndrome of the nervous system imply a high likelihood of tumor recurrence. Repeat cancer screening should be undertaken.
Similarly, a relapse or sudden worsening of neurological symptoms in a patient known to have a paraneoplastic syndrome of the nervous system, but whose cancer was thought to be in remission, should raise a high index of suspicion for cancer recurrence.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage paraneoplastic syndromes of the nervous system?
The following lifestyles and home remedies might help you cope with paraneoplastic syndromes of the nervous system:
Many people with cancer benefit from education and resources designed to improve coping skills. If you have questions or would like guidance, talk with a member of your health care team. The more you know about your condition, the better you’re able to participate in decisions about your care.
Support groups can put you in touch with others who have faced the same challenges you’re facing. If you can’t find an appropriate support group where you live, you might find one on the internet.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: September 14, 2017 | Last Modified: September 14, 2017
Paraneoplastic syndromes of the nervous system. http://www.mayoclinic.org/diseases-conditions/paraneoplastic-syndromes/home/ovc-20315084. Accessed September 14, 2017.
Paraneoplastic Neurologic Syndromes. https://rarediseases.org/rare-diseases/paraneoplastic-neurologic-syndromes/. Accessed September 14, 2017.