ABSTRACT
In the later decades of the 20th century, systematic extraoperative study with implanted subdural grids resulted in finer anatomic subdivision, competing descriptive terminologies, and the recognition of a lateral negative motor area.4-7
Figure 107.1 shows the lateral and mesial negative motor areas in relation to nearby homunculi. The descriptive terms ‘lateral’ and ‘mesial’ negative motor areas used in this chapter are synonymous with primary and supplementary negative motor areas (PNMA, SNMA). Inhibitory effects due to stimulation of mesial and lateral negative motor areas must be recognized in context with other forms of cortically-mediated motor inhibition (Figure 107.2), which will be described further below.
