6 BOLD fMRI helps neurosurgeons determine surgical strategy before an operation. 3 ⇓– 5 Hence, a novel method is needed to localize the motor cortex to achieve higher accuracy and reliability.īlood oxygen level–dependent (BOLD) fMRI is a reliable preoperative method for mapping functional regions of the brain that allows assessment of the function of cortical and subcortical regions.
2 However, due to morphologic deviations, tumor infiltration, and edema, hand knobs cannot be localized through typical structural landmarks. The hypothesis that the hand knob (hand motor cortex), whose shape resembles the Greek letter Ω the in axial plane, represents the hand motor cortex is well-recognized. Previous studies have investigated various ways of localizing the motor cortex. 1 It is crucial to identify the motor cortex accurately, especially areas relevant to hand movement. Because the anterior structure is responsible for motor function, brain tumors in this area cause transient motor function deficits and even permanent paralysis. The sensorimotor area is divided by a central sulcus.
ABBREVIATIONS: BOLD blood oxygen level–dependent DCS direct cortical stimulation DD deviation distance for the midpoint of the hand knob on the lesion hemisphere D-min the shortest distance from the tumor to the hand knob
