The purpose of this study is to assess the effect of vibration of the plantar surface of the foot on peripheral neuropathy.

Background: Peripheral neuropathy has a prevalence approaching 10% in the general population. The pathophysiology of peripheral neuropathy is poorly understood or undetermined. While many causes of peripheral neuropathy are known, a significant number of cases are idiopathic. The most common cause of neuropathy relates to glucose intolerance or overt diabetes. Exogenous factors such as smoking constrict small cutaneous blood vessels, thereby inhibiting small nerve fiber nutrition. Symptoms of neuropathy include numbness, pain, difficulty with balance, lack of temperature perception, and weakness which can lead to significant disability. Classification of neuropathies can be made based on nerve fiber size: large fiber, small fiber and mixed large and small fiber types. Plantar vibration which affects large fibers has been demonstrated to enhance peripheral and systemic blood flow, peripheral lymphatic and venous drainage (Stewart, Karman, Montgomery, & McLeod, 2005). Since fluid retention in axons, nerve sheaths and surrounding connective tissues may contribute to neuropathy, it is hypothesized that plantar vibration may repair the small peripheral fibers, thereby improving the symptoms of neuropathy.

Purposes:

1. To assess the effect of plantar vibration on regeneration of small peripheral nerve fibers, peripheral neuropathy and quality of life in patients with diagnosed peripheral neuropathy.
2. To assess the correlation of health history, demographic variables, diet, alcohol and smoking history with small fiber neuropathy analysis by skin biopsy and plantar vibration.

Design: The study will employ a cross-over experimental design with subjects acting as their own controls. Independent variables are the plantar stimulation (intervention), and the characteristics of the subjects that include health history, demographic variables, self reported diet, alcohol, and smoking history, as well as urinary cotinine (a quantitative measure of smoking history). The dependent variables are the assay of intraepidermal nerve fibers in small-fiber neuropathy, clinical assessment of peripheral neuropathy, serum levels of Hgb A1C, and quality of life measurement.

Inclusion Criteria:

• Clinical evidence of neuropathy
• Normal to moderate evidence of neuropathy on nerve conduction studies

Exclusion Criteria:

• Currently on medications with a known risk of neuropathy
• Pregnant
• Evidence of peripheral vascular disease