Effect of Transcranial Direct Current Stimulation on Peripheral Neuropathy

This study will be performed in patients with peripheral neuropathy who are walking independently, but have complains of balance problems such as recent falls or difficulty walking and show reduced vibratory and proprioceptive sensation during routine neurologic examination. These patients will be tested for proprioceptive and vibratory threshold at the toes and ankles before, during and after receiving anodal transcranial direct current stimulation (tDCS) over sensory and motor cortices. Subjects will be asked to participate in 2 sessions. In one of the sessions, decided randomly, the stimulation will be applied on the right side and in the second session it will be on the left. The tDCS portion of the experiment will begins with direct current (maximum of 2 mA) stimulation delivered through surface electrodes (TransQE from IOMED®, surface area: 25 cm2) using a Phoresor® II Auto (Model No. PM850, IOMED®, Salt Lake City, Utah 84120, USA). One electrode will be positioned above the left or right primary motor cortex, the other electrode over the forehead.