A group of rare diseases that appear in people with cancer are known as Paraneoplastic syndromes of the nervous system. These diseases can also negatively affect some organ systems (such as joints, blood, skin, and hormones). Paraneoplastic syndromes usually appear when antibodies that fight against cancer also attack their organs such as the brain, spinal cord, peripheral muscles, or nerves.
These syndromes usually provoke problems with muscle movement, coordination, sensory perception, memory, sleep, or thinking abilities. It depends on the part where diseases occur. In some cases, damage to the nervous system (NS) can be reversed using specific therapies for cancer and the immune system. In other cases, these syndromes can lead to permanent damage to the NS.
Cancer treatment and other procedures can help to prevent future damage and improve quality of life and symptoms.
Symptoms
The symptoms commonly appear suddenly within a few days after the cancer is diagnosed. They depend on the body part that is affected. Examples include:
- Weakness
- Loss of muscle tone, coordination, or fine motor skills
- Slurred speech
- Swallowing problems
- Balance and walking issues
- Stuttering
- Vision changes (such as blurred vision)
- Sleeping disturbances
- Hallucinations
- Uncontrolled movements
- Seizures
- Memory loss
If you notice any of the previous symptoms, seek medical care immediately.
Paraneoplastic Syndromes Types
Cerebellar ataxia (also called cerebellar degeneration)
In such cases, nerve cell loss happens in a certain area of the brain known as the cerebellum. It is responsible for controlling muscle functions and balance. The most common symptoms include walking problems, lack of coordination in the legs and arms, poor posture, and dizziness. Some people may also experience uncontrolled movement of the eye, double vision, difficulty swallowing, nausea, and others.
Limbic encephalitis
A syndrome that affects the limbic system of the brain provoking swelling (inflammation) is known as limbic encephalitis. This part of the brain helps to control emotions, behaviors, and memory functions. Mood changes, memory problems, seizures, hallucinations, drowsiness, or personality changes usually happen in people with this syndrome.
Encephalomyelitis
This condition causes brain and spinal cord inflammation.
Opsoclonus-myoclonus
This is a health problem, in which the cerebellum or its connections do not work as should. It commonly leads to abnormal eye movements and muscle jerks in the trunk, legs, and arms.
Stiff Person Syndrome
Serious muscle stiffness (rigidity) and painful muscle spasms occur in people with this syndrome. Commonly it impacts the legs and spine.
Myelopathy
Injury to the spinal cord occurs in people with this syndrome. Bowel and bladder function changes, weakness, and numbness are the most common symptoms.
Lambert-Eaton Myasthenic Syndrome
The communication between muscles and nerves is interrupted in those who suffer from this syndrome. The symptoms that usually appear include muscle weakness, difficulty speaking and swallowing, extreme tiredness, abnormal eye movement, double vision, and in some cases erectile dysfunction (ED).
Myasthenia Gravis
This syndrome also causes problems between nerves and muscles. Symptoms of this condition include quick fatigue, weakness, involuntary muscle movements, and breathing problems.
Isaac’s Syndrome (Neuromyotonia)
When an excess of nerve impulses that control movements appear it is known as neuromyotonia. Another name for this condition includes peripheral nerve hyperexcitability. Excess nerve impulses usually provoke muscle twitching, rippling, and cramps.
Peripheral Neuropathy
A disease in which damage occurs in the nerves that send signals between the brain and the whole body.
Dysautonomia
The common symptoms that occur in people with dysautonomia include hypotension (low blood pressure), abnormal heartbeats, and shortness of breath. This is a health problem in which damage happens to the nerves that are responsible for regulating involuntary body functions. Experts call it the autonomic nervous system and it is responsible for controlling heart rate, blood pressure, sweating, bowel and bladder functions, and others.
If you experience any paraneoplastic syndrome symptoms, immediately visit a doctor.
Causes
These syndromes are not provoked by cancer cells themselves or by their spreading (metastasis). Complications (including infections) or adverse reactions from the treatment also cannot lead to the syndromes listed above. However, paraneoplastic syndromes of the NS happen due to the body’s defense activation.
Some experts think that these syndromes are provoked by antibodies that fight against cancer cells and some white blood cells (T cells). Therefore, the immune system attacks healthy cells instead of cancerous ones.
Risk Factors
All cancer types are associated with paraneoplastic syndromes of the nervous system. However, mostly it happens in people with lung, ovary, breast, testicles, or lymphatic system cancer.
Diagnosis
To diagnose these syndromes, doctors need to perform physical examinations and blood tests usually. However, they can also perform imaging tests or spinal tap (lumbar puncture).
Clinical Examinations
Physicians will perform a physical and neurological examination. Moreover, they will ask you some questions about your symptoms to determine your muscle tone, muscle strength, balance, mood, memory, reflexes, sense of touch, coordination, vision, and hearing.
Laboratory Tests
- Blood tests – Doctors may order you to do blood tests several times to check for antibodies linked with paraneoplastic syndromes of the NS. They can also determine whether you have infections, hormone imbalances, and other metabolic conditions.
- Lumbar puncture (spinal tap) – This is a test in which your doctor will take a sample of cerebrospinal fluid (CSF). It is checked for antibodies that cannot be seen in the blood.
Imaging Tests
The following tests are often used to identify tumors or other symptoms causes. Examples include:
- Computed Tomography (CT)
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET)
Sometimes, it is not possible to find the exact cause of the symptoms. It means that you may have a small tumor and it is difficult to find it. In such cases, doctors recommend getting tested every 3-6 months until the cause of the symptoms is determined.
Treatment
Treating the cancer can help to get rid of paraneoplastic syndromes of the NS. In some cases, to lessen the symptoms, your doctor may prescribe medicines to suppress the immune system. Generally, the treatment you will receive depends on the type of disease you have. Check below some treatment options:
Medicines
The following medications are usually prescribed along with primary cancer treatment (such as chemotherapy) to reduce damage caused by the body’s defense. Examples include:
- Corticosteroids – One of the medicines is Prednisone. It is used to decrease inflammation. However, it is not advised these medications for long periods because they may lead to type 2 diabetes, hypertension, high levels of cholesterol in the blood, osteoporosis, and other health problems.
- Immunosuppressants – This is a group of medications that suppress the immune system, which helps to reduce damage to the nervous system. Physicians often prescribe Azathioprine, Mycophenolate, Rituximab, Cyclophosphamide, Cyclosporine, Methotrexate, Tacrolimus, Ravulizumab, Efgartigimod, Eculizumab.
- Anti-seizure drugs – Usually prescribed by healthcare providers for syndromes linked with abnormal electrical activity in the brain.
- Enhance connection between muscles and nerves medicines – Physicians often prescribe Pyridostigmine. This medicine helps to prevent the breakdown of the chemical messengers that are responsible for carrying signals from nerves to muscles.
Other Treatment Options
- IV immunoglobulin – This procedure gives the patient healthy antibodies from blood donors. It helps to kill damaging antibodies from the blood.
- Plasmapheresis – During this procedure, doctors use a device (blood cell separator) to separate the fluid part of the blood (plasma). Thereafter, they replace the antibodies that provoke your symptoms with other fluids and then return them to the body.
Frequently Asked Questions
What is the most common paraneoplastic syndrome?
However, one of the most common syndromes that happen in people with cancer is peripheral neuropathy. It mostly provokes the following symptoms including weakness, loss of sensory abilities, and reflexes problems.
What are the most common symptoms of the paraneoplastic syndromes of the nervous system?
These include poor posture, dizziness, lack of coordination (often occurring in the legs and arms), and walking problems. If any of the previous symptoms occur, visit a doctor immediately.
Can paraneoplastic syndromes of the NS be cured?
Unfortunately, it is not possible to cure these syndromes. The results of the treatment will depend on the cancer type and stage you experience. Discuss with your healthcare professional for more details.
