Small Fiber Neuropathy
The pain and discomfort associated with SFN may be devastating to many suffers. Often, simply walking may become a nearly impossible task. In addition, though medications may offer partial relief from pain symptoms, side-effects may often be equally difficult to tolerate. Patients should strive to work with their healthcare providers, including neurologists and mental health professionals, to improve quality of life by carefully balancing medical interventions. Any barriers to transportation, employment, and healthcare treatment should be identified and addressed.
SFN is a disorder of nerve conduction that affects an estimated 15 to 20 million Americans over the age of 40. It typically affects the small, unmyelinated (uncoated) nerves in a person’s limbs, hands, and feet. The nerves that are generally involved carry sensation to our brain about temperature and pain. The nerves that carry messages from our brains to muscles in the other direction (those that affect muscle control) are typically myelinated and therefore unaffected. Additionally, some patients may experience automatic disregulation.
Generally the longest nerves are affected first with progressively shorter nerves coming later and over time. This means that effects of SFN are usually first felt in the feet and hands. The rate of loss in sensation is variable but is generally progressive and permanent.
Signs and Symptoms
Damage to or loss of small nerve fibers commonly results in pain, burning, tingling, or numbness that is usually first felt in the feet. Rarely, symptoms may occur in the the arms, face, or chest. Though symptoms may begin slowly and gradually get worse, a burning sensation usually develops and is almost universally reported. Symptoms are usually worse at night, often affecting sleep.
Importantly, motor strength, tendon reflexes, and proprioception are preserved because they are functions of large nerve fibers.
Other common signs and symptoms:
- vague dulled sensation in one or both feet
- wooden quality in sensation of feet
- numbness in toes
- feeling as if one is walking on sand, pebbles, or golf balls
- aching pains in feet and hands
- electric shock-like or pins-and-needles sensations
- cramping of the feet and calves
- reduced pinprick and thermal sensation in the affected ares
- vibratory sensation can be mildly reduced at the toes
Signs of autonomic dysregualtion:
- dry eyes
- dry mouth
- orthostatic dizziness
- bladder incontinence
- sexual dysfunction
- trouble sweating
- red or white skin discoloration
Living with Small Fiber Neuropathy
Unfortunately, though many patients with SFN will eventually come in to see a physician, they are often told there is nothing that can be done for them. Often, only pain managment is offered to help moderate the pain. In fact, some patients are told that the pain is psychological. People who are suffering with the pain of SFN often feel hopeless, and without options for treatment. These can lead to feelings of isolation and depression that are often associated with an increased sensitivity to pain.
Often, family members and friends doubt the validity of the symptoms that the patients express. Unfortunately, doctors may also fail to appreciate how real the symptoms are as well. In fact, low patient and physician awareness of the signs and symptoms of SFN may lead to delayed diagnosis of this disorder.
The strategy in treating SFN usually first focuses on treating the underlying condition. Often due to the high rate of co-occurring type II diabetes, diet, exercise, and glucose control are stressed. Treatment of small fiber neuropathy targets the underlying cause and neuropathic pain. Secondarily, if an underlying condition cannot be identified or treated, symptom management is employed. Unfortunately for many suffers, there may be no absolute cure for their illness. This is just one of the facts about people who live with small fiber neuropathy
Symptom management may include:
- topical anesthetics
- narcotic and non-narcotic analgesics
- transcutaneous electrical nerve stimulation (TENS)
- heat, ice, and massage of painful areas
Commonly used prescription medications for neuropathic pain (may be used alone or in combination):
- gabapentin (Neurontin)
- pregabalin (Lyrica)
- amitriptyline (Elavil)
- nortriptyline (Aventyl)
- 5% lidocaine patch (Lidoderm)
- tramadol (Ultram)
- Tavee J, Zhou L. Small fiber neuropathy: A burning problem. Cleveland Clinic Journal of Medicine. 2009; 76:297-305
- Medscape (2010). “Psychogenic Pain or Peripheral Neuropathy?” Retrieved August 31. 2010. from https://www.medscape.com/viewarticle/709201