Finally, we want to know whether patients with PTLS have over-active central pain circuits in the brain. Because pain is processed through the brain's pain circuits, we wish to examine whether people suffering from PTLS have hyper-active pain circuits that make them more sensitive to pain than those who have normally-active pain circuits. To do this, we will be comparing patients with PTLS to healthy volunteers by conducting careful neurologic and brain imaging (fMRI) studies.