Objective: To determine which factors contribute to a poor outcome at 1 year after Deep Brain Stimulation (DBS) of the Subthalamic Nucleus (STN).

Background: The efficacy of STN-DBS for advanced Parkinson’s disease (PD) has been consistently demonstrated. Yet, despite accurate selection and electrode positioning, a few patients report unsatisfactory outcome.

Methods: We conducted a retrospective analysis of prospectively acquired data at University of Turin DBS Centre. Out of 203 consecutive PD patients treated with STN-DBS, we identified those with available UPDRS II scores before surgery (T0) and at 1-year follow-up (T1) respectively in the OFF medication and in the OFF medication/ON stimulation condition. We defined as “Poor DBS Responders (Poor-DBS)” those who had <20% of improvement at UPDRS-II OFF MED/ON STIM at T1. “Poor” and “Good DBS responders (Good-DBS)” were compared for demographical, clinical, cognitive and affective variables at T0 and T1. We included in the analysis: demographical and clinical variables, Schwab-England Scale (SE), UPDRS-III (in the practically defined OFF state (OFF MED) at T0 and in OFF MED/ON STIM at T1). Psychiatric assessment included Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI-X1 and X2).

Results: We retrieved baseline UPDRS II data in OFF MED from 126 subjects (Poor-DBS = 35, Good-DBS = 91). At T0 UPDRS II, UPDRS III and axial UPDRS III were significantly less impaired in poor-DBS. Motor fluctuations were also less severe in this group. UPDRS III improved at T1 in both Poor-DBS and Good-DBS (p <0.0001). UPDRS II, SE, UPDRS axial score, dyskinesia score, OFF score significantly improved at T1 compared to T0 in Good-DBS. In Poor-DBS, UPDRS II significantly worsened at T1 (p= 0.0001), SE remained unchanged (p=0.7), Axial motor UPDRS score tended to decrease but not significantly (p= 0.06), OFF time score was not modified (p=0.17). Only dyskinesia score and total UPDRS IV were improved at T1 in poor-DBS (respectively p = 0.0025 and p= 0.0055). Depression by BDI decreased only in Good-DBS (p<0.01) whereas it remained unchanged in poor-DBS. STAI-X1 and X2 did not differ between groups.

Conclusions: Our data suggest that poor outcome on activity of daily living after STN DBS in PD might be caused by mild improvement of axial symptoms and of OFF time score, despite improvement of UPDRS-III in OFF MED/ON STIM.

« Back to 2018 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/poor-responders-to-stn-dbs-in-parkinsons-disease-1-year-follow-up-study/