title: Twiddler's syndrome in spinal cord stimulation.
abstract: BACKGROUND
  The aims are to present a case series of Twiddler's syndrome in spinal cord stimulators with analysis of the possible mechanism of this syndrome and discuss how this phenomenon can be prevented.
  
  
  METHODS
  Data were collected retrospectively between 2007 and 2013 for all patients presenting with failure of spinal cord stimulators. The diagnostic criterion for Twiddler's syndrome is radiological evidence of twisting of wires in the presence of failure of spinal cord stimulation.
  
  
  RESULTS
  Our unit implants on average 110 spinal cord stimulators a year. Over the 5-year study period, all consecutive cases of spinal cord stimulation failure were studied. Three patients with Twiddler's syndrome were identified. Presentation ranged from 4 to 228 weeks after implantation. Imaging revealed repeated rotations and twisting of the wires of the spinal cord stimulators leading to hardware failure.
  
  
  CONCLUSIONS
  To the best of our knowledge this is the first reported series of Twiddler's syndrome with implantable pulse generators (IPGs) for spinal cord stimulation. Hardware failure is not uncommon in spinal cord stimulation. Awareness and identification of Twiddler's syndrome may help prevent its occurrence and further revisions. This may be achieved by implanting the IPG in the lumbar region subcutaneously above the belt line. Psychological intervention may have a preventative role for those who are deemed at high risk of Twiddler's syndrome from initial psychological screening.
authors.affiliation: The Walton Centre for Neurology & Neurosurgery, Lower Lane, Liverpool, L9 7LJ, UK. rafid@doctors.org.uk.|South East Neurosurgery and Spinal Surgery, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK. rafid@doctors.org.uk.
authors.forename: Rafid
authors.initials: R
authors.lastname: Al-Mahfoudh
authors.affiliation: The Walton Centre for Neurology & Neurosurgery, Lower Lane, Liverpool, L9 7LJ, UK.
authors.forename: Yuen
authors.initials: Y
authors.lastname: Chan
authors.affiliation: The Walton Centre for Neurology & Neurosurgery, Lower Lane, Liverpool, L9 7LJ, UK.
authors.forename: Hsu Pheen
authors.initials: HP
authors.lastname: Chong
authors.affiliation: The Walton Centre for Neurology & Neurosurgery, Lower Lane, Liverpool, L9 7LJ, UK.
authors.forename: Jibril Osman
authors.initials: JO
authors.lastname: Farah
mesh_terms: D000328:Adult; D004868:Equipment Failure; D055111:Failed Back Surgery Syndrome / Q000628:therapy*; D005260:Female; D006801:Humans; D008875:Middle Aged; D062187:Spinal Cord Stimulation / Q000009:adverse effects*; D013577:Syndrome
keywords: Failed back surgery syndrome; IPG; Spinal cord stimulation; Twidder’s syndrome