Electronic Thesis and Dissertation Repository


Master of Science


Physiology and Pharmacology


Jog, Mandar


Subthalamic (STN) deep brain stimulation (DBS) is an established treatment to alleviate the appendicular motor symptoms of Parkinson's Disease (PD). Current steering during DBS allows the unequal fractionation of current between two electrodes on the lead, resulting in a non-spherical electrical field. It is hypothesized that the way the electrical field is shaped will affect a patient’s upper limb symptom alleviation. Seven PD patients who underwent bilateral STN-DBS were tested over four weeks post-operation. 16 current fractionation settings were tested each week at an amplitude that increased weekly. Optimal setting was defined as the setting that provided the best symptom improvement based on kinematic data detected by a motion capture system and the Unified Parkinson's Disease Rating Scale. Results assessing right and left upper limb symptoms gave 14 optimal settings in seven patients, of which eight settings employed current steering either unilaterally or bilaterally, and six settings employed bilateral monopolar stimulation. Thus, the use of current steering was patient-dependent and limb-dependent; factors contributing to this finding include differences in lead placement, symptom heterogeneity, and possible differences in STN functionality.