Table 2.

Data from the PROGRESS study

Device	Abbott St. Jude Infinity™ IPG system
Enrollment	234 patients with PD (157 male; 77 female)
Demographics	Age 61.7 ± 8.4 years PD duration since onset 11.7 ± 7.6 years PD duration since diagnosis 10.2 ± 7.4 years
Number of centers	37 centers, from 7 countries
Lead configuration	2 central segmented contacts (3 segments each), 1 proximal and 1 distal ring contacts; 1-3-3-1
Clinical setting	Prospective, blinded subject, blinded observer, crossover study of directional versus non-directional stimulation
Study endpoints	Primary endpoint  Superiority benchmark: at least 60% of patients at 3 months have wider TW with directional stimulation when compared to non-directional stimulation in a randomized evaluation Secondary endpoints  Non-inferiority benchmark: 40–60% of patients at 3 months have wider TW with directional stimulation when compared to non-directional stimulation in a randomized evaluation  Comparison of UPDRS III at 3 months on non-directional stimulation versus at 6 months after switching to directional stimulation Descriptive endpoints  Patient and clinician preference at 6 months between directional and non-directional stimulation  Comparison of TW and TCS amplitudes between directional and non-directional stimulation  Device-related adverse events
Primary endpoint results	In 90.6% of patients (183/202), TW was wider with directional stimulation as compared to non-directional stimulation; primary endpoint superiority exceeded (p < 0.001)

DBS deep brain stimulation, PD Parkinson disease, TCS therapeutic current strength, TW therapeutic window