Chapter 7 Applications of combined TMS-PET studies in clinical and basic research

Publisher Summary This chapter focuses on the combination of transcranial magnetic stimulation (TMS) with positron emission tomography (PET) imaging of regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of glucose (rCMRglc). Despite limited temporal and spatial resolution, the combination of PET with TMS offers some methodological advantages over combined TMS–fMRI studies. Compared with TMS in the MRI scanner, the prerequisites for applying TMS in the PET scanner are relatively easy to establish. PET measurements give an estimate of regional synaptic activity over several tens of seconds or minutes. Combined TMS–PET studies can use the limited temporal resolution of PET as an advantage because a single PET scan will represent the summation of the effects of individual stimuli on regional synaptic activity. The major advantage of PET is that it is possible to make direct comparisons of synaptic activity among different scanning sessions. This makes PET ideally suited to comparing changes in activity because of different TMS paradigms performed on separate days.