Effect of Transcranial Direct Current Stimulation on Peripheral Neuropathy

Effect of Transcranial Direct Current Stimulation on Proprioceptive and Vibratory Sensation: Potential Benefit for Patients With 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 direct transcranial cortical stimulation (dTCS) over sensory and motor cortices. Subjects will be asked to participate in 2 sessions.

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.

Patient will receive dTCS 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) or Sham stimulation.

Direct current (DC) (maximum of 2 mA) stimulation delivered through surface electrodes. One electrode will be positioned above the left or right primary motor cortex, the other electrode over the forehead.

Vibration is measured by reading in Rydel Seiffer tuning fork that ranges between 0-8 and is a standard tool fro measuring vibration sensation at the toes. A reading of 0 means absent vibration. A reading of more than 4 at the toes are considered normal. Change between assessment at 20 minutes and 10 minutes at the toes will be assessed. A recording of less than 4 indicates an abnormal results and a lower number means worse neuropathy. For example, reading of 0 means absent vibration feeling which indicates worse neuropathy than a reading of 2.

Inclusion Criteria: Peripheral Neuropathy Walking independently but with problems with balance Exclusion Criteria: Prominent weakness at the ankle Not able to walk independently History of Seizure Cardiac Pacemaker Metal implants in the head Increased intracranial pressure Pregnancy