Advanced Neurophysiology Measures

This chapter describes paired- and triple-pulse techniques aimed at probing corticospinal physiology. Most commonly, TMS applications have used a pair of sequential pulses in the same brain location, or in two different locations. For paired-pulse TMS using a single coil targeting one brain region, pulses are delivered in close succession, requiring the stimulator to have greater than a single capacitor and precise timing control. By observing MEP amplitude change because of a prior conditioning pulse, local intracortical inhibitory and facilitatory influence on the corticospinal system can be examined. A similar approach can be applied using two coils, each in separate brain locations, to examine the influence of one brain region over the other. Single-pulse TMS can also be paired with peripheral nerve stimulation, wherei. TMS is delivered to unilateral primary motor cortex, and temporally associated with electrical stimuli in the periphery. The techniques described in this section have a range of applications including to investigate the pathophysiology of neurological or psychiatric disease, or the effect of intervention.