Pain in the foot of the elderly. Symptoms of peripheral neuropathy. Most symptoms are numbness in the fingertips and foot.

Neuropathy is probably one of the biggest misunderstood areas of medicine. Partially because neuropathy does not fall under one medical speciality and partially because the term neuropathy encompasses many different illnesses.  

I find that the easiest way to explain the types of neuropathy is to group the neuropathies by what is happening to the nerve:

Axonal Nerve Damage (Damage to the wire)

If you have a problem with the long part of the nerve that sends the information, kind of like having a problem with the telephone line it is called axonal neuropathy.  The reason it is called axonal is because the neuropathy is caused by the long part of the nerve known as an axon being damaged.  The best way to think about this is to think of wire where parts of the wire has been damaged.  Kind of like an old cellphone charger where you have to place the cord “just right” for it to charge your phone.  

The following illnesses cause “axonal neuropathy” (wire damage neuropathy)

• Diabetes

• Critical illness

• Longstanding HIV infection

• End-stage kidney disease (aka “Uremic polyneuropathy”)

• Amyloidosis

• Hypothyroidism

• Vitamin deficiencies

• Lyme disease

• Toxic — due to alcohol, chemotherapy exposure, and most heavy metals

Demyelinating Nerve Damage (Damage to the insulation around the wire)

Other illnesses cause “demyelination” the best way to think of this form of nerve damage is like a wire where the insulation surrounding the wire has been damaged:

This type of nerve damage is usually caused by:

• Autoimmune illnesses (for example Guillain-Barré syndrome*)

• n-hexane exposure

Environmental (physical damage to the wire due to the environment)

The third type of nerve damage is environmental meaning the nerves were damaged by something in the environment.   Environmental factors can also impact nerve health in many ways. 

Environmental nerve damage has been caused by:

• Vibration-induced nerve damage 

• Prolonged cold exposure

• Low oxygen supply 

Each of these types of neuropathy can be determined with some testing.  Once you determine what type of nerve injury you have there are many ways to go about fixing the problem.

First step is to control the pain — we will often use a small device that can generate an energy field around a nerve or a set of nerves while we treat the nerve.  Chronic pain isn’t a joke as anyone who suffers from it will tell you and getting out of pain is the first step to healing.  There are many reasons why but one of the most important is that if you are in chronic pain the pain causes release of flight or fight chemicals called catecholamines.  These are the chemicals that get released if you are suddenly startled or are in physical danger like before a fight.  These chemicals cause your heart to beat faster and shift blood flow away from organs that don’t need it and towards the muscle to get your body ready to either fight or take flight (run away). Being in this state will likely stop any healing process. 

So what do you do to stop the pain and then heal the nerve?

There is now technology that can turn off pain from nerves.  This technology is call a neural stimulator (not to be confused with tens units or shock like devices).  The neural stimulator generates an energy field around the nerve or group of nerves and can interrupt painful patterns.  It is kind of like a remote control for your pain.  It essentially allows you to turn off your pain and replace it with a pleasant sensation.  For most patients, once the pain is controlled then sleep cycles return to normal blood pressure often will level out and blood pressure medications are often decreased.  Once the body is in the state there are several ways to heal the damaged nerves which we will cover in our next post.