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Development and Positioning Reliability of a TMS Coil Holder for Headache Research


  • Edward P. Chronicle PhD,

  • A. Jane Pearson PhD,

  • Cheryl Matthews BA

  • From the Department of Psychology, University of Hawaii at Manoa, Hawaii (Dr. Chronicle); Department of Psychology, Lancaster University, United Kingdom (Dr. Pearson); Department of Psychology, University of Maryland Baltimore County, Maryland (Ms. Matthews).

Address all correspondence to Edward P. Chronicle, Department of Psychology, University of Hawaii at Manoa, Honolulu, HI.


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.