title: Stability of symptom control after replacement of impulse generators for deep brain stimulation.
abstract: OBJECTIVE
  Impulse generators (IPGs) for deep brain stimulation (DBS) need to be replaced when their internal batteries fail or when technical problems occur. New IPGs are routinely programmed with the previous stimulation parameters. In this study, the authors evaluate the stability of symptom control after such IPG replacements.
  
  
  METHODS
  The authors retrospectively analyzed the outcome of 56 IPG replacements in 42 patients with various movement disorders treated using DBS.
  
  
  RESULTS
  Stable symptom control was found in 65% of single-channel IPG replacements and 53% of dual-channel IPG replacements. Worsening of symptoms resulted primarily from changes in stimulation effects requiring reprogramming of stimulation parameters (17% of dual-channel IPG and 25% of single-channel IPG). In 14% of dualchannel IPG replacements, instability resulted from erroneous extension adjustment with change in laterality. A new short circuit of active with previously inactive contacts of the quadripolar stimulation lead resulted in a worsening of symptoms in 4% of replacements.
  
  
  CONCLUSIONS
  Replacement of the IPG requires careful follow-up of patients with DBS to ensure stable symptom control.
authors.affiliation: Neurological Rehabilitation Center Godeshoehe, Bonn, Germany. allert@godeshoehe.de
authors.forename: Niels
authors.initials: N
authors.lastname: Allert
authors.forename: Holger
authors.initials: H
authors.lastname: Kirsch
authors.forename: Waldemar
authors.initials: W
authors.lastname: Weirich
authors.forename: Hans
authors.initials: H
authors.lastname: Karbe
mesh_terms: D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000295:instrumentation*; D011211:Electric Power Supplies; D004567:Electrodes, Implanted; D004867:Equipment Design; D004868:Equipment Failure; D006801:Humans; D009069:Movement Disorders / Q000150:complications / Q000628:therapy*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome