Investigation of central motor pathways: Magnetic brain stimulation
The ability to stimulate percutaneously the central nervous system of conscious humans without causing pain has opened up new areas for neurophysiological investigation in the early diagnosis of neurological disease, and has furthered the understanding of normal and abnormal motor control. Magnetic stimulators are now available that can excite both upper and lower limb areas of the motor cortex, as well as cranial nerves, motor roots, and deeply sited peripheral nerves. This chapter looks at their application in a clinical scenario, which include: measurement of central motor conduction time; assessment of completeness of spinal cord injury; and possibly evaluation of neurodevelopmental delay in children with neurodegenerative and other related diseases. The technique can be used serially to monitor progress of disease or after neurological injury or to examine the effects of drugs, and it can be used safely in neonates and children.