Directional Lead: Investigation of Rotational Current Steering, Ease of Use of Clinical Effects Map, and Therapeutic Outcomes of Deep Brain Stimulation

This study will compare various program settings for the bilateral stimulation
of the subthalamic nucleus using the Boston Scientific's implantable Vercise*
PC Deep Brain Stimulation System for the treatment of levodopa-responsive,
moderate to severe idiopathic PD. The Vercise* PC System is capable of
delivering stimulation similar to other commercially available DBS systems.
However, the Vercise* PC System combined with the directional lead also
features an expanded parameter range when compared to commercially available
conventional cylindrical electrodes, including the ability to shape stimulation
in the plane orthogonal to the long axis of the lead ("directional
stimulation"), and at settings that utilize independent current sources for
multiple contacts (*current steering*).
This study aims to characterize the effects of directional stimulation in
subjects implanted with this novel technology.

The primary objective is to characterize the programming effects of Boston
Scientific Vercise* PC System using the Deep Brain Stimulation Directional Lead
for bilateral subthalamic nucleus DBS for the treatment of Parkinson*s disease
in acute and chronic settings.
The exploratory objectives are to evaluate the directional marker, changes in
impedance over time, collect induced field potentials and to explore
sensitivity to current steering settings. In addition, to assess use and
usefulness of the Vercise* Navigator Steering mode controls and Clinical
Effects Scores capture in the Directional Lead Clinical Effect Maps on the
Vercise* Programmer.

Prospective, multi-center, open label study with double-blinded exploratory and
crossover phases. This is a post CE-mark study within the indications for use.

Routine implantation of Boston Scientific's Vercise* PC Deep Brain Stimulation
System with the directional lead

Patients who have DBS for Parkinson*s disease but are not in this study share
similar risks associated with the implant procedure and deep brain stimulation
therapy.
The following risks maybe associated with patients* participation in the
clinical study:
• Subjects may find it difficult, uncomfortable, or tiresome to complete study
visits, study-diaries and questionnaires.
• Subjects may experience various symptoms related to the temporary withdrawal
of Parkinson medications and withdrawal of neurostimulation, which is a
condition required of specific study visits. Symptoms may include, but are not
limited to, worsening of Parkinson*s disease signs, apathy, anxiety,
disturbance in cognition, or changes in sleep. In addition, the discontinuation
of Parkinson medications is associated with a remote risk of developing a
life-threatening condition known as neuroleptic malignant syndrome.
• As various deep brain stimulation settings are tested, subjects may
experience side effects including, but not limited to, a sensation of tingling,
muscle spasm, change in speech, mood, vision, cognition, disturbance of
balance, coordination, tremor, dizziness.
• Subjects with postural instability or gait disturbances either due to their
Parkinson*s disease or as a side effect of DBS may be at a risk of falling
while completing motor tasks as required for certain study assessments.

To complete the study measurements, subjects will spend additional time at the
hospital and/or doctor's office including some visits that may not be per
center's standard of care.

As the potential benefit for the study subject, the study doctor might get
extra insights from the study-related measurements that can be used to optimize
the stimulation settings for subject's therapy, potentially resulting in
improved clinical outcomes and/or reduced side effects.