An In-vitro Study of Electrodes Impedance in Deep Brain Stimulation

The success of Deep Brain Stimulation (DBS) therapy in movement disorders is highly reliant on the number of electric charges delivered to the brain through the implanted contact electrodes. A high electrode impedance will count the flow of these changes, affecting the clinical benefit of the treatment. DBS patients show impedance variation, and many of them lose therapeutic benefits after a while because of high impedance. The aim of study is to reveal the effect of long-term electric stimulation on the impedance of the electrical electrodes of DBS lead contacts in vitro. This study is conducted from March 2019 to November 2019 in the Department of Physiology and Medical Physics at the College of Medicine, Al-Nahrain University. The electric impedance of DBS electrodes is measured regularly for nine months in vitro. These measurements are conducted using two pairs of lead DBS electrodes: one inserted in normal saline impregnated with a carbidopa-levodopa pill and activated by a DBS electric pulses generator, and another pair as the control without stimulation. The recorded data shows an increase in the impedance of DBS electrodes over long-term electric stimulation and reversing the polarity of the stimulation may cause the impedance of the electrodes to decrease.