Safety of rTMS to non-motor cortical areas in healthy participants and patients.
OBJECTIVE
rTMS is increasingly being used for stimulation to non-motor areas, but available safety guidelines are derived from experience with motor cortex rTMS. We reviewed the literature and our own data to assess the safety of rTMS to non-motor areas.


METHODS
We reviewed for adverse effects all articles published from January 1998 to December 2003 that applied rTMS to non-motor areas, and analyzed data from our own studies from January 1997 to December 2003.


RESULTS
Adverse effects were infrequent and generally mild. Headache was the most common, occurring in 23% of the subjects and more frequent with frontal rTMS. More serious adverse effects were rare and consisted of two seizures and four instances of psychotic symptoms induced by rTMS to the dorsolateral prefrontal cortex in patients with depression.


CONCLUSIONS
Overall, as currently applied rTMS to non-motor areas appears to be safe with few, generally mild adverse effects. In future studies, we recommend systematic reporting of adverse effects and careful documentation of machine type, coils used, and actual intensity as a function of maximum stimulator output. Phosphene threshold might be used to index stimulation intensity when rTMS is applied to the visual cortex, and research should be directed to identifying other indexes of intensity for TMS to other non-motor areas.


CONCLUSIONS
rTMS under the present guidelines is safe, with minimal adverse effects, when applied to non-motor areas.
Machii
Katsuyuki
K
Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, KS-452, Boston, MA 02215, USA.
Cohen
Daniel
D
Ramos-Estebanez
Ciro
C
Pascual-Leone
Alvaro
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping; D003866:Depressive Disorder / Q000628:therapy*; D004307:Dose-Response Relationship, Radiation; D005071:Evoked Potentials / Q000502:physiology / Q000528:radiation effects; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012189:Retrospective Studies; D012196:Review Literature as Topic; D050781:Transcranial Magnetic Stimulation / Q000009:adverse effects*