Metabolic neuropathies are nerve disorders that occur with diseases that disrupt the chemical processes in the body. Nerve damage can be caused by many different things such as:
- A problem with the body's ability to use energy, often due to a lack of enough nutrients (nutritional deficiency).
- Dangerous substances (toxins) that build up in the body.
Diabetes is one of the most common causes of metabolic neuropathies, but some metabolic disorders are inherited while others will develop overtime due to various diseases.
Common symptoms of metabolic neuropathy include:
- Initial symptoms begin insidiously and are most prominent distally in the lower extremities. Sensory disturbances exhibit a typical "length related pattern," with involvement of the toes that advances to the feet and legs.
- The upper limbs are affected more rarely; however, when upper limbs are involved, symptoms develop in the same pattern, with involvement of the fingers spreading to the hands and forearms in a glovelike pattern.
- In advanced stages, sensory symptoms may involve the anterior part of abdomen and trunk (hence the term "trunk neuropathy"), leading sometimes to the erroneous diagnosis of myelopathy. In extreme cases, the head may be affected.