To study the impact of deep brain stimulation surgery on gait parameters in Parkinson Disease population using 3D motion analysis and kinematic software.

Deep brain stimulation (DBS) of Globus Pallidus internus (GPi) and Subthalamic Nucleus (STN) improves several symptoms in patients with Parkinson Disease (PD) such as tremor, bradykinesia and helps to reduce the burden of drug related side effects such as dyskinesia. There is no clear consensus on the impact of DBS on gait.

Three dimensional motion analysis (MA) is performed routinely at our center pre and post DBS.  We randomly selected 10 PD patients who were treated with DBS with lead placement in either GPi or STN. Four patients had bilateral GPi lead placement. One patient had bilateral STN lead placement. Remainder of the patients had unilateral lead placements (2 patients in STN and 3 patients in GPi location). All patients completed pre-surgical and post-surgical MA. Kinematic gait parameters were measured in the “on” state and included step length, stride length, forward velocity, cadence, total support time, swing phase, initial double support, single Support time and step width. Paired T-test for the pre and post-surgical kinematic data of each limb was conducted.

Forward velocity as well as cadence speed were decreased post DBS surgery.  Average decrease in forward velocity was 17.9 cm/s (Standard Deviation (SD): 23.85 cm/s; p= 0.041) on the right side and 17.36 cm/s (SD: 23.93 cm/s; p=0.047) on the left side. Cadence decreased on average by 10.1565 steps per minute (SD: 12.74 steps/min; p=0.032) on the right side and 9.80 steps per minute (SD: 12.89; p=0.039) on the left side.

DBS was associated with decreased gait velocity and cadence in the “on” state, which likely hampers the overall agility of the individual. Future plans include comparing site dependent (GPi vs STN) differences with gait parameters.