Nervous System Side Effects in Childhood Cancer

central-nervous-system-diagram-flowchart-5510e01aa4d7f

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.

Nervous system side effects from cancer and cancer treatments are very common. The nervous system is made up of two parts:

  • The Central Nervous System (CNS) which consists of the brain and spinal cord; and
  • The Peripheral Nervous System (PNS), which are the nerves outside of the CNS that convey information back and forth between the body and the brain and control movement, the senses (touch, hearing, sight, taste, and smell) and the functioning of the internal organs (stomach, lungs, and heart).

 

Symptoms

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 as well as any changes in symptoms with their Oncology Team, so that they can work out a regimen of palliative or supportive care for them.

Nervous System side effects caused by cancer or cancer treatments include:

  • Balance, Dizziness, Nausea, and Vertigo problems
  • Cognitive/ Thought-Process Changes including decreased memory, problem solving, and calculation
  • Coordination and Movement problems, including problems with holding objects, posture, or walking
  • General Weakness that causes an overall lack of strength; weakness on one side of the body, or drowsiness
  • Hearing Loss and/or a ringing in the ears (tinnitus)
  • Organ Function changes such as Constipation; Incontinence (not being able to control the flow of urine); or Impotence
  • Pain from a tumour pressing on the nerves or damage to the nerves from treatment
  • Paralysis of different parts of the body; this can range from one side of the body to a smaller area like the muscles in the face.
  • Peripheral Neuropathy (damage or irritation to the peripheral nerves)
  • Seizures 
  • Slurred Speech or difficulty expressing oneself or understanding speech
  • Swallowing Difficulties 
  • Taste and Smell changes
  • Vision Loss and/or blurred or double vision

 

Causes

Nervous system side effects can occur as a result of the cancer itself, the cancer treatments, other medications, or other disorders.

The above symptoms could lead to a cancer diagnosis, appear soon after treatment, or may even only appear several years after treatment.

Possible causes of nervous system problems include:

  • Cancers that affect the nervous system, such as brain cancer and sarcomas of the nerves (e.g. Neurofibrosarcoma, Malignant Peripheral Nerve Sheath Tumour, and Peripheral Primitive Neuroectodermal Tumour).
  • Cancers that have spread to the brain or spinal cord
  • Tumours growing in other parts of the body that press on nerves
  • Chemotherapy – Some types of chemotherapy (e.g. chemotherapy injected directly into the spine) may cause Peripheral Neuropathy.  Other types of chemotherapy may cause other nervous system side effects.
  • Radiation Therapy – especially radiation to the head and neck, radiation to the spine, or whole-body radiation treatment
  • Surgery – Sometimes nerves are damaged during surgery to remove a tumour or to perform a biopsy
  • Specific Medications – Some anti-nausea drugs, Opioid pain killers and Anticonvulsants can cause nervous system problems
  • Infections causing swelling or inflammation of the brain, spinal cord, or inner ear
  • Conditions or Symptoms related to cancer or cancer treatments, including Anaemia, Dehydration, Fatigue, Stress, or Depression
  • Other Conditions or Disorders not related to cancer, including Diabetes, Vitamin deficiency, Thyroid dysfunction, Human immunodeficiency virus (HIV), Stroke, Alzheimer’s disease, Multiple sclerosis, or Nerve injury

 

There is a network of nerves running across each and every part of the body carrying signals back and forth. What are they all connected to? The brain and the spinal cord. Nervous system is chiefly made of the brain, spinal cord and wide network of nerves.

 

Management/Treatment

Nervous system side effects can make it difficult for individuals to complete their usual daily activities, even for children at play.

Some of the symptoms caused by cancer treatment will disappear once treatment ends, but some may be ongoing. Although nerve damage and nervous system side effects may not be preventable, most are manageable if found early enough.

Once diagnosed, treatment or management of nervous system side effects will depend on the type of problem and the cause. There are several ways in which to treat or manage nervous system problems, including:

  • Medicines to prevent nausea and vertigo
  • Antibiotics to treat infections
  • Corticosteroids to reduce inflammation and swelling
  • Pain Medications, including opioids
  • Antidepressants
  • Medications to treat peripheral neuropathy
  • Nerve Blocks and Transcutaneous Electric Nerve Stimulation (TENS), for pain relief
  • Occupational Therapy to maintain motor skills needed for daily activities
  • Physical Therapy, to improve physical strength, balance, coordination, and mobility
  • Speech Therapy, to improve speech and learn ways to change speech as needed
  • Neuropsychological Evaluation to check cognitive function
  • Changes to the Home Environment to increase safety, such as installing handrails in the bathroom; non-skid rugs; extra lighting, and checking water temperature with an elbow instead of the hands

It is critical to your child’s well-being and future that you report any nervous system side effects to their doctor or healthcare team as soon as you notice them so that treatment can begin as soon as possible, as well as to prevent the symptoms from worsening.