T1-, T2-, and diffusion-weighted MRI was used to determine whether repetiti
ve transcranial magnetic stimulation (rTMS) affects the blood-brain barrier
or induces localized brain edema. In 11 healthy individuals, 1,200 to 3,80
0 stimuli were applied over the visual cortex of one hemisphere in series o
f 5-, 10-, or 20-Hz stimulus trains. MRI performed 6 minutes to 6 hours aft
er rTMS did not show pathologic changes in conventional MRI sequences, afte
r application of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA),
or by determining apparent diffusion coefficients.