Transcranial magnetic stimulation as a complementary treatment for aphasia.

Functional brain imaging with nonfluent aphasia patients has shown increased cortical activation (perhaps "overactivation") in right (R) hemisphere language homologues. These areas of overactivation may represent a maladaptive strategy that interferes with, rather than promotes, aphasia recovery. Repetitive transcranial magnetic stimulation (rTMS) is a painless, noninvasive procedure that utilizes magnetic fields to create electric currents in discrete brain areas affecting about a 1-cm square area of cortex. Slow frequency, 1 Hz rTMS reduces cortical excitability. When rTMS is applied to an appropriate cortical region, it may suppress the possible overactivation and thus modulate a distributed neural network for language. We provide information on rTMS and report preliminary results following rTMS application to R Broca's area (posterior, R pars triangularis) in four stroke patients with nonfluent aphasia (5-11 years after left hemisphere stroke). Following 10 rTMS treatments, significant improvement in naming pictures was observed. This form of rTMS may provide a novel, complementary treatment for aphasia.