Directional Deep Brain Stimulation Linked to Wider Therapeutic Window in Parkinson Disease
After 3 months of treatment, an overwhelming number of clinicians and patients preferred directional over omnidirectional DBS.
Matthew Brodsky, MD
Data presented at the 2020 MDS Virtual Congress, September 12–16, 2020, from the PROGRESS study (NCT02989610) revealed that 90.6% of patients with Parkinson disease (PD) had a wider therapeutic window (TW) when undergoing treatment with directional deep brain stimulation (DBS) compared with omnidirectional DBS.1
The study included 234 patients (mean age, 62 years [±8]; 33% female) who received subthalamic nucleus (STN) DBS programed with omnidirectional stimulation for 3 months followed by directional stimulation for 3 months.
A blinded, off-medication evaluation of TW for directional vs conventional stimulation at 3 months, the primary end point of the study, was met with superiority for directional (P <.001) DBS. Additionally, patients showed a mean increase in TW of 41% (2.98 [±1.38 minimum amplitude (mA)]) compared with 2.11 (±1.33 mA) for omnidirectional DBS (P <.001).
Scores on the Unified Parkinson Disease Rating Scale (UPDRS) part III motor score (on medication) were improved in both groups at both timepoints. Upon the conclusion of the 6-month study, 53% (102 of 193) of participants blinded to stimulation type preferred the period with directional stimulation, while 26% (50 of 193) preferred the omnidirectional period and 21% (41 of 193) had no preference.
Similarly, 113 of 193 clinicians (59%) reported they preferred the directional period, compared with 41 (21%) who chose the omnidirectional period. Investigators noted that there were improvements in the minimum amplitude required to achieve therapeutic benefit and the side effect threshold, leading to a 40% wider TW.
Additional end points at 3, 6, and 12 months included adverse events (AEs), therapeutic current strength (TCS), medication reduction, quality of life, and UPDRS part III motor score. Full results including 12-month data will be made available at a later time point, according to the study authors.
Abbott, whose Infinity DBS system was used during the study, released initial data from PROGRESS in March 2019. At the time, Matthew Brodsky, MD, medical director of Oregon Health and Science University’s DBS program and primary investigator of the trial, said in a statement, “These data are very encouraging as they further reinforce that directional deep brain stimulation therapy may benefit a wide variety of patients living with Parkinson disease.”2
The Infinity DBS system is currently the only directional DBS system approved to target all major areas associated with movement disorders, including PD and essential tremor. It received approval for an expanded indication to target the internal globus pallidus, an area of the brain that may improve symptoms of PD, in January 2020.3
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