During neurosurgical resection of brain tumors within brain areas for motor control, it is important to monitor motor function. For this muscle motor evoked potentials are used. Those are elicited by transcranial and direct cortical stimulation. Motor responses are recorded from muscles. In neurosurgical procedures for spinal cord tumors, the same methods are used, but additionally motor activity is recorded from the spinal cord. This is called spinal motor evoked potentials. It is known that the relation between spinal and muscle motor evoked potentials helps to extent the resection of spinal cord tumors. This study implements the spinal motor evoked potential into brain tumor surgery and analyses the relationship between spinal and muscle motor evoked potentials. With this, detection of injury to the brain area for motor control might be discovered earlier and thus tumor resection can be performed safely.