What is neuropathy?
Motor nerves carry commands from the central command center (the brain and spinal cord) to the end point, the muscles that carry out the commands: the muscles of our arms and legs, muscles in our face, and throat.
Sensory nerves carry sensation back to the command center, and carry the sensation of hot and cold, and pain. When there is damage to the sensory nerves, this changes the level of sensation. Sometimes, this causes numbness; other times, pain.
In non-cancer situations, arthritis and vertebral discs pressing on the nerves exiting or entering the spinal column can impinge on the nerves. Nerves in the hand are impinged on as they pass through the narrow wrist canal, causing Carpal Tunnel Syndrome.
Diabetes can cause neuropathy, when it is uncontrolled. The elevated blood sugars change the conduction function of the nerves that we don’t fully understand.
In cancer related neuropathy, the common causes include
-The tumor itself, pressing on the nerves around it.
-The surgery, which damages the nerves as the tumor and surrounding lymph nodes are removed
-Radiation treatment, which can cause scarring in the region being radiated, trapping nerve tissue in the scar
-Some chemotherapy drugs, which have known side effects. Some of that neuropathy is initially transient, and a decision is made as to whether that drug is necessary for curing that cancer, or can be reasonably switched out to an alternate drug. If the same drug is continued, the nerve toxicity can become cumulative and permanent.
What can you do for cancer related neuropathy?
-Relieve pressure on the nerves, when feasible. E.g. if a collapsing vertebra is causing pressure on a nerve, a procedure called vertebroplasty can strengthen and prop up the vertebra, and relieve the pressure.
-steroid injections near the root of the nerve can decrease local inflammation.
-recognize the side effects of the chemotherapy drugs and switch when appropriate.
-Medicines to change nerve conduction, e.g. gabapentin, or amitriptyline.
-Pain medications to control the pain
-Acupuncture and other complementary therapies.