Objective: This study evaluates effect of medication and stimulation on transfers and gait in people with PD post STN-DBS using an automated, quantitative assessment involving body-worn inertial sensors.
Background: The Timed Up and Go (TUG) is a physical performance test in which the ability to stand, walk 3meters, turn, walk back and sit down is timed. It is correlated with functional mobility2 and may more accurately predict falls than the pull test1. The QTUG uses body-worn inertial sensors for quantitative gait and mobility assessment via the TUG test. This is an automated assessment of axial features which is poorly served by the current gold standard assessment, i.e. the 4 axial elements of the UPDRS III, used to determine candidacy and outcomes of DBS.
Method: Assessments were completed using the QTUG 6 to 36 months post STN-DBS in 4 conditions: Stimulation ON/Medication OFF(ON/OFF), Stimulation OFF/Medication OFF(OFF/OFF), Stimulation OFF/Medication ON(OFF/ON) and Stimulation ON/Medication ON(ON/ON). Twenty-one participants (16 males, 5 females, aged 59+6 years, disease duration 155+58 months) were included. Data was analysed using repeated measures ANOVA and pairwise comparisons.
Results: There was an improvement in TUG record time, transfer score and turn score from OFF/ON to ON/ON (p<0.05). There was an improvement in TUG time and average double support from OFF/OFF to ON/ON (p<0.05). Stride length improved from OFF/OFF to OFF/ON (p<0.05). There were no significant differences in other temporal or spatial gait parameters analysed.
Conclusion: Significant changes in TUG record time and composite transfer and turn scores indicate a positive effect of stimulation on functional mobility and relative reduction in falls risk, both independently and in combination with medication. There is potential to add this quantitative, automated gait assessment to a wider suite of automated assessments to remove bias, inter and intra-rater variability when selecting DBS candidates and evaluating their outcomes.
References: 1. Foreman KB, Addison O, Kim HS, Dibble LE. Testing balance and fall risk in persons with Parkinson disease, an argument for ecologically valid testing. Parkinsonism Relat Disord. 2011;17:166–171. doi: 10.1016/j.parkreldis.2010.12.007
2. Viccaro LJ, Perera S, Studenski SA. Is timed up and go better than gait speed in predicting health, function, and falls in older adults? J Am Geriatr Soc. 2011;59:887–892. doi: 10.1111/j.1532-5415.2011.03336.x.
To cite this abstract in AMA style:
F. Ruggieri, E. Reynolds, C. O'Keeffe, J. Inocentes, M. Kelly, E. Donlon, M. Garvey, N. Austin, C. Fearon, C. Moran, R. Walsh. Evaluation of Effects of Levodopa and Subthalamic Nucleus Stimulation (STN-DBS) on Gait using Quantified Timed Up and Go Test in People with Parkinson’s Disease (PD) [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/evaluation-of-effects-of-levodopa-and-subthalamic-nucleus-stimulation-stn-dbs-on-gait-using-quantified-timed-up-and-go-test-in-people-with-parkinsons-disease-pd/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/evaluation-of-effects-of-levodopa-and-subthalamic-nucleus-stimulation-stn-dbs-on-gait-using-quantified-timed-up-and-go-test-in-people-with-parkinsons-disease-pd/