Induction of speech arrest and counting errors with rapid‐rate transcranial magnetic stimulation

Abstract

Six adult epileptic patients underwent rapid-rate transcranial magnetic stimulation (rTMS) at stimulation rates of up to 25 Hz with an 11-cm water-cooled round coil held flat on the scalp, centered over 15 different positions on each side of the scalp. The trains of stimuli were for 10 seconds while the patients counted aloud. rTMS centered over D5 or D7 induced reproducible speech arrest in all patients and counting errors in three when applied at lower intensities. There were no such speech disturbances by rTMS centered over the different positions on the right side. Intracarotid amobarbital test (IAT) demonstrated left hemispheric language dominance in all patients. Lateralization of speech arrest induced by rTMS correlated with the IAT results and may be helpful for noninvasive determination of hemispheric language dominance.

Transcranial magnetic stimulation: studying the brain--behaviour relationship by induction of ‘virtual lesions’

“…Note the relatively accurate targeting of the central sulcus (primary motor area) but the large variability in the prefrontal target. 1996b), or the role of parietal structures in hemiinattention (Pascual-Leone et al 1994a). elegantly demonstrated the use of this form of application of rTMS in a study of the functional signi¢-cance of striate cortex activation during tactile Braille reading in early and congenitally Braille subjects.…”

“…In contrast, rTMS can be safely applied over a fairly large time-window thereby providing an opportunity of testing the contribution of a cortical area to a given task without stringent temporal constraints. This type of application can be used to study hemispheric dominance for language (Pascual-Leone et al 1991;Epstein 1998) or memory (Grafman et al 1994), frontal contributions to working memory or procedural learning (Pascual-Leone et al Intrilligator. A BOLD fMRI study shows the areas of activation during visual stimulation with a display of random motion (red), vection motion (green) or both (yellow).…”

Power spectral density changes and language lateralization during covert object naming tasks measured with high-density EEG recordings

“…Because of this, in recent years, a burgeoning interest has developed in replacing the Wada test with noninvasive measures. Some of these newer techniques, like the Wada test, are based on ''deactivation" of the language cortex, such as repetitive transcranial magnetic stimulation [2], whereas other methods are based on structural imaging analyses [3]. However, the most promising novel noninvasive methods include direct measures of physiological language activation.…”

Impact of low frequency transcranial magnetic stimulation on event-related brain potentials

“…TMS studies have provided interesting results that contribute to a better understanding of the relationship between brain and behavior. Short-term effects of rTMS on cognitive processes have been reported in different studies including induction of speech arrest and counting errors (Pascual-Leone et al, 1991), alteration of visual perception (Kammer and Nusseck, 1998), enhancement and impairment of memory function (Pascual-Leone et al, 1999b), and significantly slower picture naming (Stewart et al, 2001). …”