Peripheral Neuropathy in Childhood Cancer
Symptom Management, Palliative Care, or Supportive Care to relieve side-effects is an important part of cancer care and treatment and should always form part of the overall treatment plan.
Peripheral Neuropathy occurs when the nerves outside of the brain and spinal cord (Peripheral Nervous System), are damaged. Peripheral nerves carry information back and forth between your brain and spinal cord, called the Central Nervous System (CNS), and the rest of the body.
Peripheral Neuropathies can be classified according to the type of nerve predominantly involved, or by the underlying cause.
Depending on which nerves are affected, you may notice a change in sensation, especially in your child’s hands and feet, such as numbness, tingling, or pain. Your child may also experience muscle weakness (myopathy); and changes in organ function, resulting in constipation or dizziness.
Peripheral Neuropathy can occur in relation to diseases, such as cancer, diabetes, or thyroid disorder; nutritional deficiencies, such as a deficiency in vitamin B12; or inherited conditions, such as Charcot-Marie-Tooth disease.
Cancer treatment may also cause this disorder or make it worse.
Neuropathy symptoms and their severity vary from person to person, depending on which nerves are damaged and how many nerves are affected. Symptoms may develop during cancer treatment or shortly after.
Peripheral Neuropathy can be either Chronic (a long term condition where symptoms begin subtly and progress slowly) or Acute (sudden onset, rapid progress, and slow resolution):
Acute Neuropathies demand urgent diagnosis. There are three types of peripheral nerves that can become damaged, causing a wide range of symptoms; Motor Nerves (control muscles), Sensory Nerves, or Autonomic Nerves (control automatic functions such as heart rate, body temperature, and breathing), can be affected. More than one type of nerve may be affected at the same time.
Motor Neuropathy can cause impaired balance and coordination or, most commonly, muscle weakness. Your child may have trouble walking and moving around; their legs and arms may feel heavy or weak, resulting in balance and coordination problems. It may become difficult for them to use their hands and arms, and they may have trouble with simple everyday tasks, such as brushing their teeth. They may also experience muscle cramps and muscle loss in their hands and feet.
Sensory Neuropathy may cause numbness to touch and vibration, reduced position sense causing poorer coordination and balance, reduced sensitivity to temperature change and pain, spontaneous tingling or burning pain, or skin allodynia (severe pain from normally non-painful stimuli, such as light touch);
It affects one’s sense of touch and feeling in the nerves in the hands and feet. Most individuals with cancer who develop neuropathy experience a tingling, burning, or a buzzing “electrical” sensation, or numbness. It usually starts in the toes and fingers and can continue along the hands and feet toward the centre of the body.
It can also result in a loss of sensation, making it difficult for your child to feel hot and cold temperatures or to know if they have injured themselves.
Autonomic Neuropathy may produce diverse symptoms, depending on the affected glands and organs, but common symptoms are poor bladder control, abnormal blood pressure or heart rate; dizziness or light-headedness; gastrointestinal issues, such as diarrhoea or constipation; trouble swallowing; and reduced ability to sweat normally
Causes of Peripheral Neuropathy can include genetic diseases, metabolic and endocrine diseases, toxins, inflammatory diseases, vitamin deficiency states, physical trauma, chemotherapy, electric shock, HIV, malignant diseases, radiation, shingles, and more.
Cancer-Related Risk Factors
Peripheral Neuropathy is a relatively common side effect of cancer, and although anyone with a cancer diagnosis is at risk for Peripheral Neuropathy, the following factors can increase the risk:
Paraneoplastic disorders (rare disorders triggered by the immune system’s response to cancer cells) may cause peripheral neuropathy, especially in individuals with lung cancer. Shingles, a viral infection that often presents with pain and a rash and can develop in people with weakened immune systems, and may also result in neuropathy.
It is important to let your doctor know if your child already has any symptoms of neuropathy before starting treatment or if they have any of the other risk factors that are associated with peripheral neuropathy such as:
- Chemotherapy: Specific types of chemotherapy, particularly in high doses, can injure the peripheral nerves.
- Radiation Therapy: Radiation Therapy may cause nerve injury, although it may take several years for symptoms to appear.
- Surgery: Neuropathy may develop after an operation on the lung or breast or after the amputation of a limb.
- Tumour Location: A tumour pressing on a peripheral nerve or one that grows into a nerve may damage the nerve.
Other factors that may put Children with Cancer at greater risk for developing the disorder, and which are known to cause neuropathy, include pre-existing conditions such as:
- Alcohol Abuse
- Autoimmune Diseases, such as Lupus and Rheumatoid Arthritis
- Extreme Stress
- Hereditary Peripheral Neuropathy Conditions, such as Charcot-Marie-Tooth disease
- Hypothyroidism (an underactive thyroid)
- Infections, such as HIV-AIDS
- Kidney Disease or Kidney Failure
- Lead Poisoning or Pesticides
If your child has symptoms of numbness, tingling, and pain in their feet, doctors may suspect Peripheral Neuropathy. Diagnosis can be confirmed on the basis of symptoms, clinical history, a detailed physical examination and laboratory and other testing.
A physical examination will involve examining the feet for ulceration and testing the deep ankle reflex.
Diagnostic tests used in diagnosis may include Nerve Conduction Studies (NCSs) and Electromyography (EMG). A skin biopsy may also be done to measure the density of nerves in the outer layer of the skin.
Laboratory tests may include a complete blood count; blood tests for vitamin B-12 levels; measurement of thyroid stimulating hormone levels; a comprehensive metabolic panel screening for diabetes and pre-diabetes, and a serum immunofixation test.
Preventing Neuropathy Related to Chemotherapy
There is currently no real evidence of any vitamins, supplements or medications can help one avoid getting neuropathy, although research into this is ongoing.
Relieving side effects is an important part of total cancer care and treatment, which is why you should discuss any symptoms your child is experiencing, new symptoms and changes in symptoms with their Oncology Team so that they can work out a regimen of palliative or supportive care for them.
The treatment used for Peripheral Neuropathy will depend on the cause and associated symptoms. While many individuals do recover fully from the disorder over time, the condition is sometimes more difficult to treat and may require long-term management. Many treatment strategies for peripheral neuropathy are symptomatic.
The following methods of treatment/management may provide some relief:
Although medicines cannot reverse the neuropathy, there are some that may relieve the pain if not the numbness. Medications used to manage neuropathy are related to your child’s specific situation and the cause of their neuropathy.
- Anticonvulsants and Antidepressants are the most commonly used medications to treat neuropathic pain.
- Prescription nonsteroidal anti-inflammatory drugs or very strong painkillers called analgesics may be prescribed for severe pain.
- Topical treatments, such as lidocaine patches and creams, may also help control pain.
Ensuring that your child has a a balanced diet that is also rich in B vitamins (including B1 and B12), folic acid, and antioxidants may help manage their neuropathy.
Physical and/or Occupational Therapy
Physical and/or Occupational Therapy can help to keep your child’s muscles strong and improve their coordination and balance. A therapist may also recommend assistive devices that could help your child more easily complete their usual daily activities. Regular exercise may also help reduce pain.
Massage, Acupuncture, and Relaxation Techniques may help decrease your child’s pain and reduce their mental stress.
Safety at Home
Depending on your child’s symptoms, the following tips may help them avoid injury in your home if you have sensory or motor difficulties:
- Check your child’s bath-water before they bathe to make sure that it is not too hot and they don’t burn themselves.
- Give your child non-breakable dishes and cups to use
- Install grab bars in the shower or handgrips in the tub, and put skid-free mats down.
- Install handrails on both sides of any stairways.
- Make sure that all the rooms, hallways, and stairways in your home are well lit.
- Make sure that any spilled liquid are immediately cleaned up
- Place stress mats for feet in your home and buy your child shoes with a rocker bottom sole.
- Remove small area rugs and any other clutter that could cause your child to trip or slip.
- Your child may find it easier to use a cane or walker when moving from one room to the other.