title: Randomized, Blinded Pilot Testing of Nonconventional Stimulation Patterns and Shapes in Parkinson's Disease and Essential Tremor: Evidence for Further Evaluating Narrow and Biphasic Pulses.
abstract: OBJECTIVE
  Evidence suggests that nonconventional programming may improve deep brain stimulation (DBS) therapy for movement disorders. The primary objective was to assess feasibility of testing the tolerability of several nonconventional settings in Parkinson's disease (PD) and essential tremor (ET) subjects in a single office visit. Secondary objectives were to explore for potential efficacy signals and to assess the energy demand on the implantable pulse-generators (IPGs).
  
  
  METHODS
  A custom firmware (FW) application was developed and acutely uploaded to the IPGs of eight PD and three ET subjects, allowing delivery of several nonconventional DBS settings, including narrow pulse widths, square biphasic pulses, and irregular pulse patterns. Standard clinical rating scales and several objective measures were used to compare motor outcomes with sham, clinically-optimal and nonconventional settings. Blinded and randomized testing was conducted in a traditional office setting.
  
  
  RESULTS
  Overall, the nonconventional settings were well tolerated. Under these conditions it was also possible to detect clinically-relevant differences in DBS responses using clinical rating scales but not objective measures. Compared to the clinically-optimal settings, some nonconventional settings appeared to offer similar benefit (e.g., narrow pulse widths) and others lesser benefit. Moreover, the results suggest that square biphasic pulses may deliver greater benefit. No unexpected IPG efficiency disadvantages were associated with delivering nonconventional settings.
  
  
  CONCLUSIONS
  It is feasible to acutely screen nonconventional DBS settings using controlled study designs in traditional office settings. Simple IPG FW upgrades may provide more DBS programming options for optimizing therapy. Potential advantages of narrow and biphasic pulses deserve follow up.
authors.affiliation: University of Florida Center for Movement Disorders and Neurorestoration, Gainesville, FL, USA.|Department of Neurology, Brown University, Providence, RI, USA.
authors.forename: Umer
authors.initials: U
authors.lastname: Akbar
authors.affiliation: Neuromodulation Global Research, Medtronic Inc., Minneapolis, MN, USA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Raike
authors.affiliation: University of Florida Center for Movement Disorders and Neurorestoration, Gainesville, FL, USA.|US Naval Hospital, Okinawa, Japan.
authors.forename: Nawaz
authors.initials: N
authors.lastname: Hack
authors.affiliation: University of Florida Center for Movement Disorders and Neurorestoration, Gainesville, FL, USA.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Hess
authors.affiliation: University of Florida Center for Movement Disorders and Neurorestoration, Gainesville, FL, USA.
authors.forename: Jared
authors.initials: J
authors.lastname: Skinner
authors.affiliation: University of Florida Center for Movement Disorders and Neurorestoration, Gainesville, FL, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martinez-Ramirez
authors.affiliation: University of Florida Center for Movement Disorders and Neurorestoration, Gainesville, FL, USA.
authors.forename: Sol
authors.initials: S
authors.lastname: DeJesus
authors.affiliation: University of Florida Center for Movement Disorders and Neurorestoration, Gainesville, FL, USA.|Departments of Neurology and Neurosurgery, University of Florida, Gainesville, FL, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
mesh_terms: D000368:Aged; D055592:Biophysical Phenomena; D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000379:methods*; D004734:Energy Metabolism / Q000502:physiology; D020329:Essential Tremor / Q000628:therapy*; D005917:Globus Pallidus / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy*; D010865:Pilot Projects; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
keywords: Biphasic pulses; Parkinson's disease; deep brain stimulation; essential tremor; irregular patterns; narrow pulse width