Small Fiber Neuropathy Dysfunction of Small Nerve Fibers Welcome Welcome to the University Hospital Maastricht (azM/MUMC+). You have been referred by your GP or specialist to the neurology outpatient clinic because you have symptoms typical of small fiber neuropathy. What is a small fiber neuropathy? Small fiber neuropathy is a form of polyneuropathy. The word ‘poly’ originates from Greek and means “many”. Neuropathy originates from the Latin and translates as “nerve disorder”. Polyneuropathy is essentially a disorder where a considerable number of nerves malfunction. In the case of small fiber neuropathy, it is the small nerve terminals located under the skin surface that are specifically affected. These small nerve fibers are responsible for pain and temperature sensation, and for autonomic functions (functions that take place unconsciously). Symptoms Symptoms of small fiber neuropathy may include: • Burning, sharp or shooting pain • Reduced sensation in relation to temperature sensitivity (warm/cold) or pain • Gastric or bowel complaints • Fluctuations in blood pressure • Palpitations • Increased or decreased sweating • Dry eyes or dry mouth • Symptoms relating to sexual function, which may include impotence Diagnosis When your doctor believes you are suffering from polyneuropathy, usually electrodiagnostic studies (EMG) are performed. However, with this examination small nerve fibers cannot be tested. Therefore, EMG studies are unable to reveal small fiber abnormalities. In order to diagnose small fiber neuropathy, additional investigations must be performed. These include: • Examination of temperature sensation (temperature threshold testing) • Examination of the conductivity of heat stimuli (contact heat evoked potentials) • Skin biopsy Skin biopsy is an easy and minimally invasive technique, which permits the examination of the small sensory nerves in the skin. The skin biopsy allows for the identification of these nerves. In small fiber neuropathy, the number and shape of the nerves is abnormal. This can be recognized under the microscope. Causes There are numerous underlying causes for small fiber neuropathy: • Diabetes mellitus • Impaired glucose tolerance • Inflammatory diseases, e.g. sarcoidosis or vasculitis (inflammation of blood vessels) • Coeliakie (gluten intolerance) • HIV • Certain medications • Alcohol abuse • Certain vitamin lack or excess • Certain hereditary diseases Treatment If possible, the underlying cause of the small fiber neuropathy should be treated. However, this is often impossible. Treatment will then focus on pain reduction. There are three groups of neuropathic pain drugs: • Antidepressants • Antiepileptic drugs • Opioids Contact If you have any questions after reading this information, please consult your doctor. More information: www.smallfiberneuropathy.info Visiting Address: P. Debeyelaan 25, wijk 29, Maastricht Post Address: Postbus 5800 6202 AZ Maastricht T: 043-‐387 65 43 I: www.azm.nl