title: Observation and modeling of deep brain stimulation electrode depth in the pallidal target of the developing brain.
abstract: OBJECTIVE
  It is unclear how brain growth with age affects electrode position in relation to target for children undergoing deep brain stimulation surgery. We aimed to model projected change in the distance between the entry point of the electrode into the brain and target during growth to adulthood.
  
  
  METHODS
  Modeling was performed using a neurodevelopmental magnetic resonance imaging database of age-specific templates in 6-month increments from 4 to 18 years of age. Coordinates were chosen for a set of entry points into both cerebral hemispheres and target positions within the globus pallidus internus on the youngest magnetic resonance imaging template. The youngest template was nonlinearly registered to the older templates, and the transformations generated by these registrations were applied to the original coordinates of entry and target positions, mapping these positions with increasing age. Euclidean geometry was used to calculate the distance between projected electrode entry and target with increasing age.
  
  
  RESULTS
  A projected increase in distance between entry point and target of 5-10 mm was found from age 4 to 18 years. Most change appeared to occur before 7 years of age, after which minimal change in distance was found.
  
  
  CONCLUSIONS
  Electrodes inserted during deep brain stimulation surgery are tethered at the point of entry to the skull. Brain growth, which could result in a relative retraction with respect to the original target position, appears to occur before 7 years of age, suggesting careful monitoring is needed for children undergoing implantation before this age. Reengineering of electrode design could avoid reimplantation surgery in young children undergoing deep brain stimulation.
authors.affiliation: Complex Motor Disorder Service, Evelina Children's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom; King's College London, London, United Kingdom. Electronic address: Daniel.lumsden@nhs.net.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Lumsden
authors.affiliation: King's College London, London, United Kingdom.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ashmore
authors.affiliation: King's College London, London, United Kingdom.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Charles-Edwards
authors.affiliation: Functional Neurosurgery, King's College Hospital, King's College Hospital NHS Foundation Trust, London, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Selway
authors.affiliation: Complex Motor Disorder Service, Evelina Children's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Lin
authors.affiliation: Clinical Neurosciences, Institute of Psychiatry, King's College London, London, United Kingdom; Functional Neurosurgery, King's College Hospital, King's College Hospital NHS Foundation Trust, London, United Kingdom.
authors.forename: Keyoumars
authors.initials: K
authors.lastname: Ashkan
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000375:Aging; D001921:Brain / Q000033:anatomy & histology / Q000254:growth & development; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000379:methods*; D004421:Dystonia / Q000628:therapy; D004567:Electrodes, Implanted; D005260:Female; D007839:Functional Laterality; D005917:Globus Pallidus / Q000033:anatomy & histology / Q000254:growth & development; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods
keywords: Deep brain stimulation; Developing brain; Dystonia; Implanted electrode; Pallidum