Brain Tumours

Language mapping

• Bipolar stimulation • Cortical mapping started at low stimulus (1 mA) • Constant-current generator delivers biphasic square wave pulses in 4-s trains at 60 Hz across 1 -mm bipolar electrodes separated by 5 mm • Stimulation sites marked with sterile numbered tickets • Throughout motor and language mapping, continuous ECoG used to monitor after discharge potentials