About Neuropathy
Neuropathy, also called peripheral neuropathy, occurs when nerve cells regulating movement and bodily sensations stop functioning properly. It typically affects nerves in the hands and feet, but other nerves are occasionally involved. Neuropathy can develop as a side effect of chemotherapy and other medical treatment for cancer, including for brain and spinal tumors.
People with neuropathy may lose some sense of touch in their fingertips. Their fingers or toes may go numb or tingle, a feeling sometimes described as “pins and needles.” These sensations may also occur in the throat or other areas of the body.
Although some signs of neuropathy may appear suddenly, changes in sensation usually build gradually and may worsen with repeated doses of chemotherapy.
Neuropathy is usually the most severe right after undergoing chemotherapy, with a tendency to lessen before the next dose. Symptoms usually peak about 3 to 5 months after the last treatment.
If neuropathy does settle down after its peak, it is a gradual process that typically lasts several months. While the abnormal sensations may disappear completely, they may also only partially ease up. In some cases, neuropathy is irreversible and never diminishes in intensity. Your doctor will work with you to manage symptoms if they are present.
Symptoms of neuropathy
Neuropathy symptoms vary by the type of nerve affected, with 3 types of nerves controlling different functions in the body.
- Sensory nerves
- Motor nerves
- Autonomic nerves
Because neuropathy may involve damage to more than 1 type of nerve, you may experience a combination of symptoms.
The 3 types of nerves and their symptoms that cause symptoms of neuropathy are:
- Motor nerves: If neuropathy affects these nerves, symptoms include:
- Muscles that twitch or cramp
- Weak or achy muscles
- Swallowing or breathing difficulties (nerves that help the muscles move in your throat and chest)
- Sensory nerves: If neuropathy affects these nerves, symptoms include:
- Numbness
- Tingling sensation
- Burning sensation
- Sensitivity to touch
- Autonomic nerves: If autonomic nerves are affected, the symptoms include:
- Heat intolerance
- Excessive sweating
- Bowel, bladder or digestive problems
- Changes in blood pressure that can cause dizziness
Risk factors for neuropathy
Several risk factors can lead to neuropathy, including treatment with certain chemotherapy drugs and other prescription medications. Nerve damage may also result from conditions such as diabetes or from the development of tumors, especially in the brain or along the spinal cord.
Diagnostic tests for neuropathy
Diagnosing neuropathy involves several steps. Your doctor typically starts by asking about your medical history, including any previous illnesses that might have weakened your immune system or involved radiation therapy. Your doctor will also ask about your family history, your habits, and your lifestyle.
Doctors use a neurological exam to diagnose neuropathy. During this exam, your doctor looks for changes to your vision, hearing, balance, coordination, strength, and reflexes. These changes can identify which nerves may be affected.
Imaging tests that take pictures of your brain also help diagnose neuropathy. Doctors use a variety of imaging technologies, each offering different insights on structures that may be affecting nerve function. Your doctor may also order a nerve function test to evaluate nerve damage.
CT scan
Computed tomography (CT) scans combine multiple x-rays and enable doctors to see structures in the brain that may affect nerve function.
MRI
Magnetic resonance imaging (MRI) uses radio waves and magnets to create images of brain structures. A technologist or nurse may perform this scan by injecting contrast dye into your arm to illuminate changes in soft tissue that may relate to your symptoms.
Nerve conduction study (NCS)
An NCS uses electrical impulses to evaluate how well your nerves carry instructions to your muscles. It also assesses your sense of touch and ability to feel vibrations, cold, and heat. To start the test, a member of your care team places 2 electrodes on your skin over the targeted nerve. One electrode stimulates the nerve with a mild electrical impulse while the other records how fast the impulse moves through the nerve.
Current as of: 2/2020
Stanford Health Education, 2020