Optically tracked neuronavigation increases the stability of hand-held focal coil positioning: evidence from "transcranial" magnetic stimulation-induced electrical field measurements.
The stability of hand-held coil positioning with neuronavigated versus conventional transcranial magnetic stimulation (TMS) is still underinvestigated. Eleven operators naïve for neuronavigation were asked to position and maintain a figure-of-eight-shaped coil over a dipole probe placed within of a polystyrene reproduction of the human head and scalp, in correspondence of the right primary motor cortex. Ten monophasic magnetic pulses were delivered at 46% maximal stimulator output (MSO) in two different experimental conditions: (1) assisted by an optically tracked neuronavigational system; and (2) without neuronavigation. With neuronavigated stimulation, both standard deviation and coefficient of variation of the voltages induced in the dipole probe were significantly lower than without neuronavigation. Results were confirmed in four operators performing a longer-lasting experiment using 50 magnetic pulses in each condition, at an intensity of at 40% MSO. Findings show that optically tracked neuronavigation improves the stability of focal coil positioning.
Cincotta
Massimo
M
Unità Operativa di Neurologia dell'Azienda Sanitaria di Firenze, Ospedale Piero Palagi, Firenze, Italy. cincotta@unifi.it
Giovannelli
Fabio
F
Borgheresi
Alessandra
A
Balestrieri
Fabrizio
F
Toscani
Lucia
L
Zaccara
Gaetano
G
Carducci
Filippo
F
Viggiano
Maria Pia
MP
Rossi
Simone
S
D000328:Adult; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods; D005260:Female; D006257:Head / Q000033:anatomy & histology; D006801:Humans; D008875:Middle Aged; D008953:Models, Anatomic; D056888:Patient Positioning; D050781:Transcranial Magnetic Stimulation / Q000295:instrumentation / Q000379:methods; D055815:Young Adult