Correct Way to Code and Bill Brain Mapping
Surgically removing brain tumors adjacent to "eloquent" or 
functional regions of the brain poses significant risks for causing neurological impairments. Brain Mapping is performed for such eloquent cortex identification or to determine where the motor/sensory transition exists. CPT 95961 ( Functional cortical and subcortical mapping by stimulation and/or recording of electrodes on brain surface, or depth electrodes, to provoke seizures or identify vital brain structures; initial hour of physician attendance) code should be used for the first hour of attendence.
For any subsequent attendence CPT 95962 (each additional hour of physician attendance) should be used.
Note that the physician must be physically present in the room for these codes to be billed.This cannot be performed or interpreted remotely by a physician.
Also CPT codes 95961- 95962 (functional cortical mapping) are not eligible for the 95920 (intraoperative neurophysiology testing per hour) hourly add on code.