Preoperative assessment: motor function

Abstract With the advent of FMRI, it was quickly recognized that a new tool might be available for the preoperative mapping of motor function. The motor system was extensively studied in both healthy volunteers and also in patients. The clear relationship between the activation of the primary motor cortex and the corresponding electrophysiological response even led to the use of intraoperative mapping as a method to validate motor FMRI. Today, preoperative motor FMRI seems to be the major clinical application of a method that has become an indispensable tool of research. Motor control is a complex organized process that involves several motor, sensory, and associative areas. Anatomically, the motor cortex, neocortical association areas, the basal ganglia, the cerebellum, the brainstem, and the spinal cord are involved. The main cortical motor areas include the primary motor cortex (M1), the supplementary motor area (SMA), the presupplementary motor area (pre-SMA), the cingulate motor area (CMA), the premotor area (pre-MA) and the prefrontal cortex (PFC). The location of these areas is usually described using the Brodmann classification which subdivides the cortex into more than 40 areas using cytoarchitectonic criteria (Fig. 2.1).