Small Fiber Peripheral Neuropathy is a disease which primarily affects the terminal end-branches of peripheral nerves. The net result is the disintegration of the nerve fiber cytoskeleton, and eventually complete nerve loss.
Symptoms often manifest as pain, tingling, or numbness in a stocking and/or glove distribution.
Epidermal Nerve Fiber Density Analysis (ENFD) is a test which allows direct visualization of; small nerve fibers, changes indicative of degeneration and structural integrity.
ENFD testing provides patients with a definitive diagnosis of small fiber peripheral neuropathy and an assessment of its degree of severity. When clinically indicated, dietary supplementation may be provided to both diminish the symptoms of neuropathy, and to improve overall epidermal nerve health.
Peripheral neuropathy affects roughly 15-20 million persons over the age of 40 in the United States
What is small fiber peripheral neuropathy (SFPN)?
• Small fiber peripheral neuropathy is a disease which primarily affects the terminal end-branches of peripheral nerves
• The net result is disintegration of the nerve fiber cytoskeleton, and eventually complete nerve loss
• Often manifests as pain, tingling, or numbness in a stocking and/or glove distribution
• Usually not identified by large nerve fiber tests such as nerve conduction studies
Conditions which may cause small fiber peripheral neuropathy (SFPN)
• Metabolic causes such as diabetes mellitus, metabolic syndrome, hyperlipidemia
• Inherited causes such as Fabry’s disease, Tangier’s disease, familial amyloid polyneuropathy
• Toxic causes such as chemotherapy, alcoholism, solvent exposure.
• Autoimmune causes such as Sjogren’s syndrome, vasculitis/polyarteritis nodosa
• Amyloidosis (non-inherited forms of amyloidosis, e.g. lymphoma or plasma cell dyscrasias
• Infection (HIV, Hepatitis C, Lyme disease)
• Idiopathic (For a relatively large percentage of cases, there is no identifiable cause of SFPN)
What is Epidermal Nerve Fiber Density analysis (ENFD)?
• Epidermal Nerve Fiber Density analysis is a test which allows direct visualization of small nerve fibers.
• Small nerve fibers are assessed for structural integrity, and counted
• Changes indicative of degeneration are predictive of future disease
• A diminished number of small nerve fibers are indicative of established disease; the lower the count, the more severe the disease state
How is ENFD analysis performed?
• Anesthesia is applied around the biopsy site located 10cm proximal to the lateral malleolus
• A 3mm punch biopsy is performed taking care not to crush the surface epithelium
• The biopsy is either placed in Zamboni’s fixative overnight, rinsed, and mailed; or placed in Zamboni’s fixative and mailed immediately