The Effect of Transcranial Direct Current Stimulation for Chronic Pain on Ophthalmologic Parameters

tDCS is a noninvasive brain stimulation technique that utilizes low amplitude direct currents applied via scalp electrodes to modulate the level of cortical excitability.Several studies have demonstrated that tDCS applied over the sensory-motor cortex has been able to decrease pain sensation and to increase pain threshold in healthy subjects and in chronic pain patients. The aim of this study was to test whether daily sessions of anodal tDCS repeated for 5 consecutive days may be effective in reducing pain in a large number of chronic pain patients. The cathode is usually applied over the right forhead above the eye. The aim of the study is to test whether daily sessions of tDCS repeated for 5 consecutive days will influence on ophthalmologic parametrs.

Patients will recieve tDCS in a 5-day period of treatment. The participants will go through full ophtalmologic examination before and after the treatmnet In addition to the ophtalmologic examination Pain will be measured using visual analog scale (VAS) for pain and the short form McGill questionnaire (SF-MPQ). Disability will be measured using the ( Pain Disability Index (PDI) of Life-54 scale (MSQoL-54). Depressive symptoms and anxiety will also be evaluated using the Center for Epidemiological Studies-Depression Scale and the State-trait Anxiety Inventory (STAI). Cognitive function will be mesured using minimental test.