Perturbation of visuospatial attention by high-frequency offline rTMS

TY - JOUR

T1 - Perturbation of visuospatial attention by high-frequency offline rTMS

AU - Jin, Yu

AU - Hilgetag, Claus C

PY - 2008/7

Y1 - 2008/7

N2 - The contribution of different cortical regions to visuospatial attention can be probed with the help of perturbation techniques, such as transcranial magnetic stimulation (TMS). Repetitive TMS (rTMS) has also been suggested as a tool for the therapy of brain injuries, by adjusting the neural excitability of injured or intact brain regions. Low- and high-frequency rTMS have been shown to result in subsequent (offline) reductions or increases of local cortical excitability, respectively. Previous studies demonstrated that low-frequency (1 Hz) rTMS of posterior parietal cortex (PPC) produced significantly reduced detection of stimuli in the visual hemifield contralateral to the stimulation site, as well as increased ipsilateral detection. We here explored the functional impact of high-frequency (20 Hz) rTMS with an attention task similar to that of a previous low-frequency study (Hilgetag et al. in Nat Neurosci 4:953-957, 2001). Normal healthy subjects (N = 14) received high-frequency rTMS (20 Hz, 10 min, 50% stimulator output) over right or left PPC (coordinate points P4 or P3). After stimulation of the right PPC, detection of single visual stimuli in the contralateral hemifield was significantly impaired. Generally, rTMS of right and left PPC produced mirror-symmetric trends in reduced contralateral detection. These effects were still present after post-TMS sham stimulation (more than 20 min after the end of active rTMS). The results suggest that attentional function can be perturbed by high-frequency rTMS as well as by low-frequency rTMS, despite potential differences in the underlying neural mechanisms.

AB - The contribution of different cortical regions to visuospatial attention can be probed with the help of perturbation techniques, such as transcranial magnetic stimulation (TMS). Repetitive TMS (rTMS) has also been suggested as a tool for the therapy of brain injuries, by adjusting the neural excitability of injured or intact brain regions. Low- and high-frequency rTMS have been shown to result in subsequent (offline) reductions or increases of local cortical excitability, respectively. Previous studies demonstrated that low-frequency (1 Hz) rTMS of posterior parietal cortex (PPC) produced significantly reduced detection of stimuli in the visual hemifield contralateral to the stimulation site, as well as increased ipsilateral detection. We here explored the functional impact of high-frequency (20 Hz) rTMS with an attention task similar to that of a previous low-frequency study (Hilgetag et al. in Nat Neurosci 4:953-957, 2001). Normal healthy subjects (N = 14) received high-frequency rTMS (20 Hz, 10 min, 50% stimulator output) over right or left PPC (coordinate points P4 or P3). After stimulation of the right PPC, detection of single visual stimuli in the contralateral hemifield was significantly impaired. Generally, rTMS of right and left PPC produced mirror-symmetric trends in reduced contralateral detection. These effects were still present after post-TMS sham stimulation (more than 20 min after the end of active rTMS). The results suggest that attentional function can be perturbed by high-frequency rTMS as well as by low-frequency rTMS, despite potential differences in the underlying neural mechanisms.

KW - Adult

KW - Attention

KW - Brain Mapping

KW - Electric Stimulation

KW - Female

KW - Functional Laterality

KW - Humans

KW - Male

KW - Photic Stimulation

KW - Psychomotor Performance

KW - Reaction Time

KW - Space Perception

KW - Transcranial Magnetic Stimulation

KW - Journal Article

U2 - 10.1007/s00221-008-1449-y

DO - 10.1007/s00221-008-1449-y

M3 - SCORING: Journal article

C2 - 18563400

VL - 189

SP - 121

EP - 128

JO - EXP BRAIN RES

JF - EXP BRAIN RES

SN - 0014-4819

IS - 1

ER -