Objective: To evaluate which approach patients with Parkinson’s disease (PD) choose when they change direction of walk and if L-dopa and subthalamic nucleus deep brain stimulation (STN-DBS) may inuence this feature. Background: Two main strategies are known for turning while walking: step strategy (the direction change is performed with 3 steps or more without pivoting) and spin strategy (turning on one foot or both feet simultaneously). Overall turning strategies have rarely been studied in PD although this phase of walking is particularly risky with regard to falls. Method: The video-recordings of 171 PD patients that completed 180-degree turn-tasks were analyzed by two blinded raters before and on average one year after DBS-implantation both off and on L-dopa and off and on stimulation. The turning strategies were classied into three categories: 1) spin turn strategy, 2) step turn strategy, and 3) mixed strategy (spin plus step), the turn is accomplished with 1-2 steps and a pivot. The characteristics of the patients with different strategies were compared. Results: In evaluating a video-based turning strategy, two raters had almost perfect agreement (k=0.894). The strategy preference was different based on treatment condition (untreated, treated with L-dopa or with L-dopa plus stimulation), X2(4) =67.2, p<0.0001. The spin turn was found in 12% of patients in drug-Off, 28% in drug-ON at baseline and in 44% in drug-ON/stim-ON condition at follow-up. In the three treatment conditions patients with spin turns have signicantly lower UPDRS III scores compared to step turn patients (p<0.004, p<0.0001, p<0.002); step turn patients have poorer postural and gait control (PIGD) scores (p<0.0005, p<0.001, p<0.017). Conclusion: The spin turn is associated with improving the patients’ motor conditions. It may well serve as a simple motor parameter but still needs prospective testing. Since improvements in motor score in patients with uctuation are also associated with behavioral and particularly need changes we cannot exclude that this also represents a feature of psycho-motor interaction. To cite this abstract in AMA style: O. Gavriliuc, S. Paschen, A. Andrusca, C. Schlenstedt, G. Deuschl. Spin turns and step turns in advanced Parkinson’s disease: a new clinical gait sign? [abstract]. Mov Disord. 2019; 34 (suppl 2). https://www.mdsabstracts.org/abstract/spin-turns-and-step-turns-in-advanced-parkinsons-disease-anew-clinical-gait-sign/. Accessed December 4, 2023. MDS Abstracts - https://www.mdsabstracts.org/abstract/spin-turns-and-step-turns-in-advancedparkinsons-disease-a-new-clinical-gait-sign/