Eloquent areas in the Sawaya study are the motor/sensory cortices, visual center, speech center, internal capsule, basal ganglia, hypothalamus/thalamus, brainstem, and dentate nucleus
Grade I lesions are located in noneloquent brain
Grade II lesions in near-eloquent brain
Grade III lesions in eloquent brain 1).
see Sawaya grading
1)
Sawaya R, Hammoud M, Schoppa D, Hess KR, Wu SZ, Shi WM, et al. Neurosurgical outcomes in a modern series of 400 craniotomies for treatment of parenchymal tumors. Neurosurgery 1998;42:1044-56.