To compare active contact location between novel segmented leads and traditional ring leads used in subthalamic nucleus deep brain stimulation (STN DBS) for the treatment of Parkinson’s disease (PD). Additionally, utilization of directional stimulation was assessed in patients implanted with segmented leads.

We reviewed programming data from PD patients implanted with STN DBS at Emory University Hospital from 2017-2019. Narrow-spaced leads from three FDA-approved manufacturers were used (proximal contact targeted above the dorsal STN border). Active (negative) contact(s) for each patient were extracted at the 12-month follow-up (if not available, then 6-month). AC-PC coordinates were determined from postoperative CT using CranialVault software. The active contact(s) were classified as dorsal or ventral based on its position on the lead (proximal or distal two, respectively), or depth (averaged if multiple) with respect to the AC-PC plane (above or below -3 mm, respectively). Among patients using segmented leads, stimulation was further classified as ring or directional. Chi-square was used for statistical analysis.

The analysis included 54 patients (29 ring, 25 segmented) and 102 leads. By the position on the lead, the percentage of dorsal/ventral/both contacts was 32%/59%/9% for ring and 47%/43%/9% for segmented leads. AC-PC-based classification indicated dorsal/ventral as 66%/34% for ring and 64%/36% for segmented leads. The active contact location did not vary by lead type and was more likely dorsal by AC-PC classification (p=0.003). Among patients using segmented leads, ring stimulation was more common than directional (74%/26%; p=0.001). 

In accordance with previous work, dorsal stimulation is preferred for traditional ring leads, as well as for novel segmented leads. Directional stimulation is utilized in a minority of patients.