Study and modulation
of human cortical excitability with transcranial magnetic stimulation.
Pascual-Leone A, Tormos JM, Keenan J, Tarazona F, Canete C,
Departamento de Fisiologia, Universidad de Valencia, and Instituto Cajal,
Consejo Superior de Investigaciones Cientificas, Spain.
Transcranial magnetic stimulation (TMS) can be applied
in different paradigms to obtain a measure of various aspects of cortical
excitability. These different TMS paradigms provide information about
different neurotransmitter systems, enhance our understanding about
the pathophysiology of neuropsychiatric conditions, and in the future
may be helpful as a guide for pharmacological interventions. In addition,
repetitive TMS (rTMS) modulates cortical excitability beyond the duration
of the rTMS trains themselves. Depending on rTMS parameters, a lasting
inhibition or facilitation of cortical excitability can be induced.
These effects can be demonstrated neurophysiologically or by combining
rTMS with neuroimaging techniques. The effects do not remain limited
to the cortical area directly targeted by rTMS, but affect a wider neural
network transynaptically. Modulation of cortical excitability by rTMS
may in the future be useful not only as a research tool but also as
a therapeutic intervention in neurology, psychiatry, and neurorehabilitation.
Trends Neurosci. 1991 Jun;14(6):217-8