A new device to improve target localization for transcranial magnetic stimulation therapy.

BACKGROUND: Accurate identification of cranial midline structures is essential for many targeting techniques that use repetitive transcranial magnetic stimulation (rTMS), including the Beam F3 method used for depression treatment. OBJECTIVE: Evaluate whether a novel, laser-sighted device will assist with more accurate identification of the cranial midline relative to standard scalp-based measurement procedures. METHODS: Three trained TMS technicians performed repeated scalp-based measurements to identify the inion and vertex on five subjects (n = 54 measurements). Measurements were compared to points identified with the midline localizer device and the true midline as defined by MRI midline structures. RESULTS: Use of the midline localizer was more accurate for midline identification than technician measurement (p = 0.00025) and the ratio of localizing the midline within 5 mm was higher (78% versus 54%, p = 0.008). CONCLUSION: Use of a laser-sighted midline localizer device can improve the accuracy of scalp measurements associated with target localization for rTMS treatment protocols.