Enhancing the quality of studies using transcranial magnetic and electrical stimulation with a new computer-controlled system.

Transcranial magnetic (TMS) and electrical (TES) stimulation of the human brain have become useful tools in neurophysiological and neuropsychological research. Here we describe an integrated system that allows experimental control, data recording and analysis of neurophysiological and neuropsychological TMS and TES procedures (including motor thresholds, recruitment curves, intracortical inhibition and facilitation with paired pulses). The system uses a multifunction input/output board and a set of virtual instruments (VI) programmed with the Labview graphical programming language. It also includes online curve fitting of recruitment curves using the Boltzmann sigmoid function and monitoring of the preinnervation grade of the target muscle. Modules for neuropsychological stimulus presentation or faster repetitive stimulation can be easily added. This system yields more accurate data recording and analysis in a user friendly and unified environment.