Axonopathy is a type of polyneuropathy, which
is a diffuse peripheral nerve disorder that is not restricted to the
distribution of a single nerve or a single extremity, and generally is
relatively symmetrical on both sides. Neuropathy results from damage the
covering on your nerves or the blood vessels that bring oxygen and nutrients to
your nerves. Damaged nerves may stop sending messages, or may send messages
slowly or at the wrong times.

Axonopathies are usually distal; they may be
symmetric or asymmetric.

Symmetric axonopathies result most often from
toxic-metabolic disorders. Common causes include the following

• Diabetes mellitus: in diabetic individuals, blood
sugar would be too high. With time, this can harm the covering on your nerves
or the blood vessels that bring oxygen to your nerves, and they will start to
“malfunction”. This damage is called diabetic neuropathy. More than half of
people with diabetes get it. Symptoms may include

o Numbness in your hands, legs, or feet

o Shooting pains, burning, or tingling



• Chronic renal insufficiency (due to chronic kidney
disease; with elevated creatinine in the blood and abnormal electrolytes) can
induce damage in the nerves

• Adverse effects of chemotherapy drugs (eg, vinca
alkaloids)

• Guillain Barré syndrome: a disorder in which the
body's immune system attacks part of the peripheral nervous system. Weakness,
tingling, and abnormal sensations that starts in the legs and progresses
quickly upwards are typical. It usually occurs after a viral illness.



Axonopathy may result from nutritional deficiencies
(most commonly, of vitamins B1, B6, B12, or E) or from excess intake of vitamin
B6 or alcohol.

Less common metabolic causes include hypothyroidism
(poor thyroid gland function), porphyria (porphyrias are a group of genetic
disorders caused by problems with how your body synthesizes a substance called
heme; heme is found especially in the red blood cells and bone marrow, where it
carries oxygen), sarcoidosis (a disease that causes inflammation, usually in
the lungs, skin, or lymph nodes. It starts as tiny, grain-like lumps, called
granulomas. It can affect any organ in your body), and amyloidosis (occurs when
abnormal proteins called amyloids accumulate and form deposits, which can
reside in organs such as the kidney and heart. This can cause the organs to
become stiff and unable to function properly).

Other causes include certain infections (eg, Lyme
disease; uncommon in our part of the world, more commonly seen in America),
drugs (eg, nitrous oxide), and exposure to certain chemicals (eg, Agent Orange,
n-hexane) or heavy metals (eg, lead, arsenic, mercury). 

When the axon (please refer to my previous answer for
the definition of axon) is not functioning as it should, there will be
neuropathy distally (at the ends of the arms and/or legs) which is distributed
in a symmetric fashion. A “stocking-glove distribution” is characteristic, with
abnormal sensation on the hands and feet, as if you’re wearing gloves and
stocking; it evenly affects the legs before the arms and progresses
symmetrically from distal (ends) to proximal areas.