Small fibre neuropathy is diagnosed from burning pain and altered temperature sensation with a normal nerve conduction study, since standard testing assesses large fibres only. Skin biopsy measuring nerve fibre density is the confirmatory test where one is needed.
Small fibre neuropathy is diagnosed from burning pain and altered temperature sensation with a normal nerve conduction study, since standard testing assesses large fibres only. Skin biopsy measuring nerve fibre density is the confirmatory test where one is needed.
This is the crux of it and the source of most frustration. Nerve conduction studies assess large myelinated fibres, which carry vibration, position sense and motor signals. Small unmyelinated fibres carry pain and temperature, and they are invisible to that test. So someone with genuine, severe burning pain can have a completely normal electrodiagnostic study. A normal result does not mean nothing is wrong; it means the problem is not in the fibres that test examines.
Burning, prickling or electric pain, usually starting in the feet and often worse at night, is characteristic. Altered temperature sensation is common, as is allodynia, where light touch such as bedsheets becomes painful. Autonomic symptoms may accompany it: dry eyes and mouth, altered sweating, light-headedness on standing, and bowel or bladder changes. Strength, reflexes and vibration sense are typically preserved on examination, which can wrongly suggest nothing is wrong.
Skin biopsy measuring intraepidermal nerve fibre density is the usual confirmatory test, arranged externally. Quantitative sensory and autonomic testing may contribute. The cause search matters as much as the confirmation: glucose and HbA1c, since impaired glucose tolerance short of diabetes is a recognised cause, plus thyroid function, B12, vitamin B6 which causes neuropathy in excess as well as deficiency, autoimmune screening, and a medication review. A proportion remain idiopathic.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.