title: Clinical safety of brain magnetic resonance imaging with implanted deep brain stimulation hardware: large case series and review of the literature.
abstract: BACKGROUND
  Over 75,000 patients have undergone deep brain stimulation (DBS) procedures worldwide. Magnetic resonance imaging (MRI) is an important clinical and research tool in analyzing electrode location, documenting postoperative complications, and investigating novel symptoms in DBS patients. Functional MRI may shed light on the mechanism of action of DBS. MRI safety in DBS patients is therefore an important consideration.
  
  
  METHODS
  We report our experience with MRI in patients with implanted DBS hardware and examine the literature for clinical reports on MRI safety with implanted DBS hardware.
  
  
  RESULTS
  A total of 262 MRI examinations were performed in 223 patients with intracranial DBS hardware, including 45 in patients with an implanted pulse generator. Only 1 temporary adverse event occurred related to patient agitation and movement during immediate postoperative MR imaging. Agitation resolved after a few hours, and an MRI obtained before implanted pulse generator implantation revealed edema around both electrodes. Over 4000 MRI examinations in patients with implanted DBS hardware have been reported in the literature. Only 4 led to adverse events, including 2 hardware failures, 1 temporary and 1 permanent neurological deficit. Adverse neurological events occurred in a unique set of circumstances where appropriate safety protocols were not followed. MRI guidelines provided by DBS hardware manufacturers are inconsistent and vary among devices.
  
  
  CONCLUSIONS
  The importance of MRI in modern medicine places pressure on industry to develop fully MRI-compatible DBS devices. Until then, the literature suggests that, when observing certain precautions, cranial MR images can be obtained with an extremely low risk in patients with implanted DBS hardware.
authors.affiliation: Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, and Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK. l.zrinzo@ion.ucl.ac.uk
authors.forename: Ludvic
authors.initials: L
authors.lastname: Zrinzo
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Yoshida
authors.forename: Marwan I
authors.initials: MI
authors.lastname: Hariz
authors.forename: John
authors.initials: J
authors.lastname: Thornton
authors.forename: Thomas
authors.initials: T
authors.lastname: Foltynie
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Yousry
authors.forename: Patricia
authors.initials: P
authors.lastname: Limousin
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D001929:Brain Edema / Q000473:pathology; D046690:Deep Brain Stimulation / Q000009:adverse effects* / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology; D019635:Neurosurgical Procedures; D011446:Prospective Studies; D011595:Psychomotor Agitation / Q000209:etiology