title: Bowstringing as a complication of deep brain stimulation: case report.
abstract: OBJECTIVE
  This retrospective case series describes bowstringing as a complication of deep brain stimulator implantation for Parkinson's disease, defined as abnormal tethering of leads between the pulse generator and stimulating electrode, associated with contracture of the patient's neck over the extension cable. There are no previous reports of this specific complication, which presumably has been more broadly classified under hardware-related complications.
  
  
  METHODS
  Bowstringing may result in discomfort, restriction of movements, and/or equipment malfunction. Patients were identified by postoperative surveillance in clinic and by review of our database of Parkinson's disease patients who had undergone subthalamic nucleus deep brain stimulator placement. The incidence of this complication was 2.6% (6/228) in our overall clinic population, composed of 0% (0/181) of patients who received a Soletra pulse generator and 12.7% (6/47) of patients who received a Kinetra pulse generator.
  
  
  METHODS
  The proportion of patients with bowstringing requiring operative revision was 83% (5/6), with 60% (3/5) patients undergoing conversion to single-channel pulse generators and 40% (2/5) undergoing revision of the original dual-channel pulse generator.
  
  
  CONCLUSIONS
  Factors associated with bowstringing include the use of dual-channel pulse generators and scar lysis complicated by seroma or infection. The mean time from implantation to bowstringing was 8.6 months with a range of 0.5 to 22 months. Bowstringing is a rare but potentially serious complication, and further study is needed to accurately predict and avoid this problem.
authors.affiliation: Department of Neurosurgery, University of Minnesota, Minneapolis, Minnesota 55455, USA. janson@memorymatters.org
authors.forename: Christopher
authors.initials: C
authors.lastname: Janson
authors.forename: Robert
authors.initials: R
authors.lastname: Maxwell
authors.forename: Akshay A
authors.initials: AA
authors.lastname: Gupte
authors.forename: Aviva
authors.initials: A
authors.lastname: Abosch
mesh_terms: D000328:Adult; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D004421:Dystonia / Q000209:etiology / Q000503:physiopathology*; D004567:Electrodes, Implanted / Q000009:adverse effects; D004868:Equipment Failure; D004864:Equipment and Supplies / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy*; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology*; D012189:Retrospective Studies