title: Development and positioning reliability of a TMS coil holder for headache research.
abstract: OBJECTIVE
  Accurate and reproducible coil positioning is important for headache research using transcranial magnetic stimulation protocols. We aimed to design a transcranial magnetic stimulation coil holder and demonstrate reliability of test-retest coil positioning.
  
  
  METHODS
  A coil holder was developed and manufactured according to three principles of stability, durability, and three-dimensional positional accuracy. Reliability of coil positioning was assessed by stimulating over the motor cortex of four neurologically normal subjects and recording finger muscle responses, both at a test phase and a retest phase several hours later.
  
  
  RESULTS
  In all four subjects, repositioning of the transcranial magnetic stimulation coil solely on the basis of coil holder coordinates was accurate to within 2 mm.
  
  
  CONCLUSIONS
  The coil holder demonstrated good test-retest reliability of coil positioning, and is thus a promising tool for transcranial magnetic stimulation-based headache research, particularly studies of prophylactic drug effect where several laboratory visits with identical coil positioning are necessary.
authors.affiliation: Department of Psychology, University of Hawaii at Manoa, Hawaii, USA.
authors.forename: Edward P
authors.initials: EP
authors.lastname: Chronicle
authors.forename: A Jane
authors.initials: AJ
authors.lastname: Pearson
authors.forename: Cheryl
authors.initials: C
authors.lastname: Matthews
mesh_terms: D004867:Equipment Design; D006261:Headache; D006801:Humans; D008280:Magnetics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012106:Research / Q000295:instrumentation*; D012886:Skull