Neuropathy describes damage to the peripheral nervous system; motor, sensory, or autonomic nerves which move information from the brain and spinal cord to every other part of the body.
Peripheral nerve fibers are classified according to size and correspond with myelination: Large nerve fibers are heavily myelinated A-alpha fibers that control motor strength, and A-beta fibers, which control touch sensation. Medium-sized fibers, known as A-gamma fibers, are also myelinated and carry information to the stretch receptors in your muscles. Small fibers include myelinated A-delta fibers and unmyelinated C fibers, which supply skin (somatic fibers) and involuntary muscles (autonomic fibers). They work together to control pain, sense of temperature, and autonomic function.
When people talk about peripheral neuropathy, they most often are referring to small fiber neuropathy. Small fiber neuropathy is a disorder of the peripheral nerves that may affect either small somatic fibers, autonomic fibers, or both. Degeneration will lead to sensory changes and autonomic dysfunction when both types of fibers are involved.
The symptoms of small fiber neuropathy typically start with burning feet and numb toes. These symptoms will progress to weakness, numbness, and tingling. This may travel upward at which time your hands and finger will also become involved.
When autonomic fibers become affected, patients may experience dry eyes, dry mouth, orthostatic dizziness or orthostatic hypotension, constipation, bladder incontinence, sexual dysfunction, trouble regulating temperature (excessive or inadequate sweating) or red or white skin discoloration.2
Exercise intolerance may result if your heart rate stays the same instead of adjusting in response to your activity level. Your ability to digest food may become impaired; feeling full after a few bites of food, loss of appetite, abdominal bloating, nausea, vomiting, difficulty swallowing and heartburn.
Superficial Siderosis patients with small fiber neuropathy require chronic pain management.
Updated: June 18, 2018